American Journal of Plant Sciences, 2011, 2, 589-600
doi:10.4236/ajps.2011.24070 Published Online October 2011 (http://www.SciRP.org/journal/ajps)
Copyright © 2011 SciRes. AJPS
589
Recent Advances in Sorghum Genetic
Enhancement Research at ICRISAT
Are Ashok Kumar1*, Belum Venkata Subba Reddy1, Hari Chand Sharma1, Charles Thomas Hash1,
Pinnamaneni Srinivasa Rao1, Bhavanasi Ramaiah1, Pulluru Sanjana Reddy2
1International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), Patancheru, India; 2Directorate of Sorghum Research,
Rajendranagar, Hyderabad, India.
Email: a.ashokkumar@cgiar.org
Received June 15th, 2011; revised August 22nd, 2011; accepted September 16th, 2011.
ABSTRACT
Sorghum is one of the most important cereal crops widely grown for food, feed, fodder/forage, and fuel in the semi-arid
tropics of Asia, Africa, the Americas and Australia. The global sorghum areas remained static as the increased area in
Africa compensated the area loss in Asia. Inspite of rapid decline in sorghum area in Asia due to competition from
other remunerative crops, sorghum grain production levels have not declined at the same rate owing to adoption of
high yielding hybrids. Though impressive gains have been made in improving productivity levels, biotic and abiotic
challenges such as shoot fly, stem borer, grain molds, and terminal drought stress continue to haunt the sorghum
growers across the world. International Crops Research Institu te for the Semi-Arid Tropics (ICRISAT) and the respec-
tive national programs are working on genetic enhancemen t of sorghum for high yield ; sh oot fly, and grain mold resis-
tance, and sweet stalk traits. In addition, research fo cus at ICRISAT also includes adaptation to postrain y season, ter-
minal drought toleran ce, and increasing micronutrient contents (Fe and Zn) in grain. Genetic and cytoplasmic diversi-
fication of hybrid parents and varieties for key traitsis critical for sustaining the productivity gains. The grain and
stover quality requirements of different market segments needs special attention in sorghum improvement research to
enhance its market value. This paper analyses the progress made in sorghum improvement research at ICRISAT in
partnership with na tional programs in recent years and the way forward.
Keywords: IC RIS AT , Sorghum, Genetic Enhancement, Grain Yield, Shoot Fly, Grain Mold, Drought, Biofortification
1. Introduction
Sorghum is fifth most important cereal crop globally and
is the dietary staple of more than 500 million people in
30 countries. It is grown on 40 m ha in 105 countries of
Africa, Asia, Oceania and the Americas. Africa and India
account for the largest share (> 70%) of global sorghum
area whileUSA, India, Mexico, Nigeria, Sudan and
Ethiopia are the major sorghum producers (http://faostat.
fao.org/site/567/default.aspx#ancor verified on July 4,
2011). It is the third most important grain crop in U.S.
Other sorghum producing countries include Australia,
Brasil, Argentina, China, Burkina Faso, Mali, Egypt,
Niger, Tanzania, Chad and Cameroon. Sorghum grain is
used mostly for food purposes (55%), consumed in the
form of flat breads and porridges (thick or thin); stover is
an important source of dry season maintenance rations
for livestock, especially in drylands; it is also an impor-
tant feed grain (33%), especially in the Americas [1].
Sorghum area, production and productivity trends in-
dicate that, globally sorghum area increased from 45
m·ha in 1970s to 51 m·ha in 1980s. Later on, there was a
fluctuation by 4 to 10 m·ha in area in the next two dec-
ades but reached to 40 m·ha by 2009. The productivity
increased from 1200 kg·ha–1 in 1970s to 1400 kg·ha–1 in
2009. Adoption of improved sorghum cultivars and man-
agement practices contributed to the productivity gains
though large differences exist in different parts of the
world for sorghum productivity (Figure 1) [2].
Sorghum is a self-pollinating, diploid (2n = 2x = 20)
with a genome, about 25% the size of maize orsugarcane.
It is a C4 plant with higher photosynthetic efficiency and
higher abiotic stress tolerance [3,4]. Its small genome
(730 Mb) makes sorghum an attractive model for func-
tional genomics of C4 grasses. Drought tolerance makes
sorghum especially important in dry regions such as
northeast Africa (its center of diversity), India and the
southern plains of the United States [5]. Genetic variation
Recent Advances in Sorghum Genetic Enhancement Research at ICRISAT
590
Figure 1. Three-year moving average for sorghum area, production, yield; and number of released varieties (3-years total)
based on ICRISAT-bred material globally.
in the partitioning of carbon into sugar stores versus cell
wall mass, and in perenniality and associated features
such as tillering and stalk reserve retention, make sor-
ghum an attractive system for the study of traits impor-
tant in perennial cellulosic biomass crops [6]. Its high
level of inbreeding makes it an attractive association ge-
netics system. Sorghum is one among the climate resil-
ient crops that can better adapt to climate change condi-
tions [2,7].
ICRISAT has a global mandate for sorghum im-
provement research and physical mandate of semi-arid
tropics (SAT) for enhancing the livelihoods of poor [8].
The total sorghum growing areas can be divided in to
eight major research domains [9].
2. Sorghum Research Domains (SRDs)
Of the total 40 m ha global sorghum area, the agro-
ecologies, growing conditions and the market require-
ments are quite different necessitating crop improvement
for various adaptations, different uses and market pref-
erences. Sorghum research activities at different loca-
tions over the years were conducted under the implicit
assumption of eight research domains delineated as ho-
mogeneous eco-regions in terms of soil and climatic con-
ditions regardless of national boundaries [9]. Table 1
summarizes the characteristics of these sorghum research
domains (SRDs) across the world. These domains are:
wide adaptability (SRD I), dual purpose with specific
adaptability (SRD II), dual purpose with fodder emphasis
(SRD III), forage sorghum (SRD IV), early-sown pos-
trainy sorghum (SRD V), late-sown postrainy sorghum
(SRD VI), irrigated sorghum (SRD VII) and extreme
altitude sorghum (SRD VIII).
ICRISAT has one of the largest collections of global
sorghum germplasm with > 36,000 accessions in its gene
bank. These accessions are maintained under short-term
and long-term storage conditions and shared with re-
search organizations globally. ICRISAT and National
Agricultural Research Systems (NARS) across the sor-
ghum growing areas are working on sorghum genetic
enhancement for traits of global and regional importance.
The target materials had been open-pollinated varieties in
Africa whereas hybrids and hybrid parents for rest of the
world. Hybrid sorghum is gradually picking up in Africa
[11]. Exploitation of global germplasm accessions through
systematic crop improvement programsto a large extent
has contributed to development of large number of sor-
ghum cultivars. The germplasm and improved materials
developed at ICRISAT are shared with public sector and
private sector partners across the globe. For e.g. during
2010, ICRISAT sent a total of 3275 seed samples of hy-
brid seed parents/breeding lines to 21 countries. India
received 2375 samples, followed by Nigeria and other
countries. Of the 2375 samples supplied in India, 888
samples were sent to public sector scientists, 1380 sam-
les to private sector scientists and the remaining 107 p
Copyright © 2011 SciRes. AJPS
Recent Advances in Sorghum Genetic Enhancement Research at ICRISAT591
Table 1. Characteristics of sorghum research domains.
Domains Production system characteristics Major constraints Locations
SRD I (wide adaptability)
Rainy season, multi-purpose grain,
stalk, fodder (fodder emphasis).
Wide adaptability (June-August
sowing)
Grain mold, shoot fly and head
bug
West Africa (southern tier), India
(Tamil Nadu, Southern Karna-
taka, Andhra Pradesh)
SRD II (dual purpose and spe-
cific adaptability)
Rainy season, dual purpose (grain
and fodder). Specific adaptability
(June sowing). Medium- to late-
maturing types
Stem borer, grain mild, midge,
shoot fly and drought
East and Southern Africa, India
(Andhra Pradesh, Northern Kar-
nataka, Maharashtra, Madhya
Pradesh, Gujarat), Latin America
(some areas)
SRD III (dual purpose, fodder
emphasis)
Rainy season, dual purpose (fodder
emphasis). Early maturing Shoot fly and stem borer
West Africa (northern tier), East
Africa (Yemen, Somalia), India
(Eastern Rajasthan), Latin Amer-
ica (some areas), China, Iran
SRD IV (forage sorghum) Rainy season, forage type (thin
stalk, tillering) and late maturing Stem borer and leaf diseases India (Northern Gangetic plains),
Pakistan
SRD V (early sown post rainy) Postrainy (early sown-before Octo-
ber). Bold grain types, dual purpose Shoot fly, charcoal rot, aphids India (South Andhra Pradesh,
South Karnataka)
SRD VI ( later sown postrainy)
Postrainy season (late sown-mid/late
October). Bold grain, photoperiod
sensitivity required, temperature
insensitive
Shoot fly, charcoal rot, drought
(shallow soils)
East Africa (Ethiopia, Sudan),
India (Gujarat, South Maharash-
tra, North Karnataka)
SRD VII (irrigated) Irrigated sorghum Iran, Egypt, Wad Medani (Sudan)
SRD VIII (extreme altitude) Others
High altitude: China and low al-
titude: Indonesia, Brazil, Ecuador,
Venezuela
Source: [9-10].
samples to farmers and NGOs. Fourteen sets of sweet
stalk trials consisting of 423 entries were sent for evalua-
tion in India, Philippines, Israel, Mexico, Mozambique
and Mali. Further seed samples were also sent to Brazil,
Mexico, U.S.A, Australia and China. During the period
1976 to 2010, a total of 242 sorghum cultivars were re-
leased globally using the ICRISAT-bred sorghum mate-
rial by private and public sector organizations including
National Agricultural Research System (NARS) partners
across the world (Figure 1). ICRISAT is a major reposi-
tory of global germplasm collection with a total of
36,774 accessions from 90 countries [12] and the existing
collections represent about 80% of the variability present
in the crop [13]. Since its establishment in 1972, germ-
plasm sources at ICRISAT have been screened and util-
ized in the development of high yielding male-sterile
lines (CK 60, 172, 2219) and restorers (IS 84, IS 3691, IS
3541). They have been valuable sources for incorporate-
ing shoot fly and stem borer resistance (IS 1082, IS 2205,
IS 2312, IS 5604, IS 5470, IS 1054, IS 18432, IS 18417,
IS 18425), midge resistance (DJ 6514, IS 3443), multiple
disease resistance (IS 3547 and IS 14387), Striga resis-
tance (IS 18331, IS 2221), drought tolerance (IS 12611
and IS 69628), high lysine content (IS 11167, IS 11758),
stalk sweetness (IS 20963, IS 15428), forage quantity
and quality (IS 1044, IS 1059) and salinity tolerance (IS
164, IS 19604) [12].
Sorghum improvement research program at ICRISAT-
Patancheru, India over the years developed more than
680 A-/B-pairs and more than 880 R-lines which were
trait specific [high yield, large grain, biotic stress resis-
tance (shoot fly, midge and grain mold) and abiotic stress
tolerance (drought and salinity), grain micronutrient (Fe
and Zn) density and sweet stalk traits] for use as parents
in hybrid development [14]. In some cases, the resistance
sources per se were directly converted into male-sterile
lines. Of late, cytoplasmic diversification and racial di-
versification has been given major thrust in sorghum
improvement [1].
Considerable progress has been made in developing
techniques to screen for resistance to four insect pests,
five diseases and drought. Apart from identification of
resistant germplasm sources (particularly shoot fly and
midge, and grain mold), considerable information has
also been generated on the mechanisms and inheritance
of resistance to insects such as shoot fly (Atherigona
soccata), stem borer (Chilo partellus), shoot bug (Peri-
grinus maidis), aphid (Melanaphis sacchari), midge
Copyright © 2011 SciRes. AJPS
Recent Advances in Sorghum Genetic Enhancement Research at ICRISAT
592
(Stenodiplosis sorghicola) and head bug (Calocoris an-
gustatus) [15]. Glossy trait at the seedling stage to select
for resistance to shoot fly, short and tight glumes for
midge resistance and long glumes for head bug resistance
have been identified as marker traits. Similarly grain
hardness, flavan-4-ols in the grain and loose panicles
helps in reducing damage by grain molds [16]. While
diversifying sorghum hybrid parents, both geographical
and racial diversity were successfully captured. The
variation in caudatum race being captured for a long time
now and more emphasis is given to exploit guinea and
durra races in recent years. Efforts are underway to di-
versify hybrid parents for shoot fly resistance (SFR) and
grain mold resistance (GMR) by introgressing genes
from new and diverse sources of resistant germplasm
lines, guinea race in particular. Postrainy season adapted
sweet sorghum parental lines development is in progress.
Some of the more recent advances in sorghum improve-
ment research at ICRISAT-Patancheru, India are summa-
rized below:
3. Hybrid Parents Improvement for Rainy
Season Adaptation
Sorghum grain produced in rainy season in India and
other Asian countries is not always preferred for human
consumption if grain gets molded especially when high
rain fall occurs during grain development stage. Most of
the mold-affected grain goes for poultry feed or for in-
dustrial uses. However, rainy season stover is important
as animal feed. The research targets are fixed based on
the crop utilization and the performance of popular
checks in a given ecology. For e.g. the research target for
India is to develop hybrid parents that yield grain 15% to
20% higher than the commercial hybrid CSH 18 (4.5
t·ha–1) and fodder about 20% higher compared to CSH 18
(13 t·ha–1).
3.1. Grain and Fodder Yields, Height and
Maturity
In addition to dual-purpose types, hybrid parents to de-
velop dwarf hybrids for mechanized harvesting and fod-
der purpose hybrids with high recovery ability (for multi-
cut forage purpose) in a range of maturity (70 to 85 days
to 50% flowering) has been the major focus. Focus is
also there on forage varieties amenable for both single-
and multi-cuts to meet the needs of farmers and dairy
Industry.
Considering that Caudatum race has been exploited
extensively for diversification of hybrid parents at IC-
RISAT, and elsewhere, greater emphasis was given for
the use of other races (durra and guinea ) for hybrid par-
ents’ development since 2000 at ICRISAT, Patancheru.
Availability of cytoplasmic-nuclear male sterility (CMS)
system, higher heterosis % in the improved hybrids, and
strong private sector presence facilitated the development
of improved hybrids in large part of the globe. In addi-
tion to the widely used Milo-cytoplasm (A1), cytoplasmic
male-sterile lines are also available in A2, A3, A4, A4M,
A4VZM, A4G1, A5, A6, 9E and KS cytoplasms [17-23].
Considering the restoration frequency, hybrid perform-
ance and comparable A1 and A2 CMS effects for grain
yield and resistance to shoot fly and grain mold, it is ad-
vantageous to use A2 CMS system for developing hybrid
parents, among the alternate cytoplasms available. This
not only increases the cytoplasmic diversity but reduces
the possibility of epidemics occurrence when a single
source of cytoplasm is used. This has been a major prior-
ity in hybrid seed parents’ development at ICRISAT. As
a result of concerted efforts, a total of 85 new race-spe-
cific A-/B-lines (39 A1 and 46 A2 CMS-systems based)
have been developed in last 10 years (Table 2).
The grain yield potential of some of the improved B-
lines (A2) was significantly higher than the control 296B
(Table 3).
3.2. Shoot Fly Resistance
Shoot fly is a major problem in late-sown crop in re-
gions/years with erratic rains. At ICRISAT, interlard-
fishmeal technique has been used for screening against
shoot fly to develop shoot fly resistant hybrid parents
[24]. While breeding for shoot fly resistance, resistant
sources in desirable agronomic background (ICSV 702,
ICSH 705, ICSV 708, PS 21318, PS 30715-1 and PS
35805) as well as other sources (IS 18551) were used in
crossing programs. Following trait-based pedigree breed-
ing approach, a large number of shoot fly resistant seed
parents for both rainy season (ICSA-/B-409 to ICSA-/B-
436) and post-rainy season adaptation (ICSA-/B-437 to
ICSA-/B-463) were developed [25]. All these B-lines
have been designated and characterized as per the Dis-
tinctness, Uniformity and Stability (DUS) test guide-
lines and their characteristics are available at ICRISAT
website: http//www.icrisat.org/text/research/grep/homepage/
sorghum/breeding/main.htm, verified on 5 July 2011 [14].
More recently, new sources of resistance IS 923, IS 1057,
Table 2. The number of race-specific A-/B-lines developed
at ICRISAT, Patancheru, India after year 2000.
Number of A-/B-lines
Race
A1 A2
Durra bold grain
Caudatum
Guinea
Feterita (Caudatum)
23
6
10
28
4
5
9
Total 39 46
Copyright © 2011 SciRes. AJPS
Recent Advances in Sorghum Genetic Enhancement Research at ICRISAT
Copyright © 2011 SciRes. AJPS
593
Table 3. Performance of sorghum advanced B-lines (A2-cytoplasm based) at ICRISAT, Patancheru during 2010 rainy sea-
son.
S. No Origin Days to 50% flowering Plant height (m)Panicle grain mold rating score
(1 = no mold, 990%)
Grain yield (t·ha–1) 100-seed weight (g)
1 SP 09 27915 76 2 2.7 2.77 2.7
2 ABT 6 74 1.9 2 2.23 2.6
3 SP 09 27943 79 2 2.3 2.06 2.3
4 SP 09 27917 73 2 3 1.88 2.4
5 SP 09 27911 73 1.9 2.7 1.73 2.6
6 PBTA2 21 73 2.1 2.3 1.66 2.8
7 PBTA2 9 69 1.5 5 1.53 2.1
8 SP 09 27939 79 2 3 1.52 2
9 SP 09 27949 77 1.8 3 1.46 2.7
20 296B 74 1.5 3.3 1.49 2.1
Grand Mean 76 1.8 3.1 1.52 2.4
CV 2.7 5.3 19 16.9 13.8
LSD 3.43 0.16 0.97 0.42 0.55
PVALUE 0 0 0 0 0.01
3.3. Grain Mold Tolerance
IS 1071, IS 1082, IS 1096, IS 2394, IS 4663, IS 5072, IS
18369, IS 4664, IS 5470 and IS 5636 are in use for de-
velopment of shoot fly resistant hybrid parents. On com-
paring the A1 and A2 systems for shoot fly resistance, no
significant differences were observed between A1 and A2
cytoplasms [26]. High yielding, shoot fly resistant hybrid
parents were developed and heterotic hybrids produced
using these parents. The need for having shoot fly resis-
tance in both female and male parents for producing
shoot fly resistant high yielding hybrids was demon-
strated [27]. In sorghum, quantitative trait loci (QTL)
governing various component traits contributing for
shoot fly resistance have been identified and mapped in
the parent IS 18551 [28] and CT Hash, ICRISAT, Per-
sonal communication). The QTL have been transferred to
two cultivated backgrounds namely, BTx623 and 296B
at ICRISAT (Hash CT, ICRISAT, Personal communica-
tion). These lines are currently being used to transfer
shoot fly resistance in to elite sorghum hybrid parents.
New B-lines with high grain yield and shoot fly resis-
tance were identified during the 2008 rainy season at
ICRISAT-Patancheru (Table 4).
Grain mold is one of the important biotic challenges for
the rainy season sorghum. Both greenhouse and field
screening techniques have been standardized by ICRI-
SAT and partners for effective screening for grain mold
resistance [16] and new sources of resistance were iden-
tified for use in breeding programs. Grain hardness, red
pericarp and pigmented testa contribute to grain mold
resistance [16]. In a study at ICRISAT, 156 grain mold
tolerant/resistant lines were identified by screening 13,000
photoperiod-insensitive sorghum germplasm lines [29].
Resistance has been found mostly in colored grain sor-
ghums with and without tannins and also in very few
white-grain sorghums [29,30]. White grained sorghums
are preferred for food use in India whereas colored grains
are preferred in other parts of the world. Using the grain
mold resistant germplasm sources, acouple of improved
hybrid parents and varieties were developed [29]. Recent
studies showed that there are no cytoplasmic differences
between A1 and A2 cytoplasms for grain mold resistance
and it is feasible to develop white pericarp grain mold
resistant high yielding sorghum hybrids with stable per-
Recent Advances in Sorghum Genetic Enhancement Research at ICRISAT
594
Table 4. Performance of advanced sorghum B-lines for ag-
ronomic traits and shoot fly resistance in the 2008 rainy
season at ICRISAT-Patancheru, India.
Genotype Days to 50%
flowering
Plant
height (m)
Shoot fly
deadhearts (%)
Grain yield
(t·ha–1)
ICSB 29001 70 1.4 38 3.51
ICSB 29002 69 1.5 71 3.63
ICSB 29003 70 1.6 40 3.57
ICSB 29004 69 2.1 45 6.09
ICSB 29005 68 1.5 46 5.33
ICSB 29006 69 1.5 54 4.47
ICSB 29017 68 1.5 33 4.50
ABT 1007 68 1.6 39 4.52
PBT 1004 69 1.8 53 4.29
Controls
IS 18551 72 3 31 2.57
296B 70 1.5 59 4.11
Swarna 69 1.8 44 4.86
Mean 69 1.73 46.02 4.28
SE (+) 1.18 0.21 14.33 0.35
CV (%) 2.95 21.33 23.93 14.00
CD (5%) 3.47 0.63 4.20 1.00
formance by using improved grain mold resistant hybrid
parents, at least one of the parents being resistant to grain
mold [31]. For identifying QTL for grain mold resistance,
mapping populations (RILs) were developed (296 B ×
PVK 801; PVK 801 × 296 B) and the phenotyping of
these populations for grain mold resistance is in progress.
Recently, 14 B-lines with a grain yield of 1.9 to 2.6 t·ha–1
and significantly superior to the check, 296 B (1.3 t·ha–1)
for grain yield were developed and all these B-lines were
tolerant to grain mold with panicle grain mold rating
ranging from 2.0 to 3.7 compared to the susceptible
check, 296B (PGMR: 4.3 on 1 to 9 scale where 1 = no
molds and 990% grain surface area covered with molds)
(ICRISAT Archival Report 2009
http://www.icrisat.org/
icrisat-archival-reports.htm verified on 5th July 2011).
3.4. Drought Tolerance
Four growth stages in sorghum have been considered as
vulnerable to drought: germination and seedling emer-
gence, postemergence or early seedling stage, midseason
or pre-flowering, and terminal or postflowering. Termi-
nal drought is the most limiting factor for sorghum pro-
duction worldwide. In sub-Saharan Africa, drought at
both seedling establishment and terminal stages is very
common. In India, sorghum is grown during both rainy
and postrainy seasons. The variable moisture availability
at both pre-flowering and post-flowering stages during
the rainy season can have severe impact on grain and
biomass yield. Climatic variability and associated geno-
type environment interactions do not permit clear defi-
nition of target environments. Opportunities to make
progress in breeding for drought tolerance occur both in
understanding the environmental control of crop growth
and in developing simplified approaches to modeling
effects of climate change [32].
Drought and/or heat stress at the seedling stage often
results in poor emergence, plant death and reduced plant
stands. Severe pre-flowering drought stress results in
drastic reduction in grain yield. Post-flowering drought
stress tolerance is indicated when plants remain green
and fill grain normally. A stay-green trait has been asso-
ciated with post-flowering drought tolerance in sorghum.
Genotypes with the stay-green trait are also reported to
be resistant to lodging and charcoal rot [33] (Figure 2).
Genetic enhancement of sorghum for drought toler-
ance would stabilize productivity and contribute to sus-
tainability of production systems in drought-prone envi-
ronments. The extent of grain yield losses due to drought
stress depends on the stage of the crop and the timing,
duration, and severity of drought stress. Sorghum re-
sponses to moisture stress at all four growth stages have
been well characterized. Variation in these responses has
been observed and found to be heritable [3]. Since the
phenotypic responses of genotypes differing in drought
tolerance can be masked if drought occurs at more than
Figure 2. Expression of stay-gre en trait (in sorghum) under
receding soil moisture conditions in a vertisol (photo cour-
tesy: C Tom Hash, Santosh Deshpande and Vincent Vadez,
ICRISAT).
Copyright © 2011 SciRes. AJPS
Recent Advances in Sorghum Genetic Enhancement Research at ICRISAT595
one stage, screening techniques have been developed to
identify drought-tolerant genotypes at each of the growth
stages, separately [34-40]. Of the several mechanisms to
circumvent drought stress in sorghum, drought escape
(related to shorter maturity durations), drought avoidance
(maintenance of higher leaf water potential, LWP), and
drought tolerance (related to greater osmotic adjustment,
OA) are important and have been well characterized [3].
However, LWP and OA did not correlate well enough
with grain yield in field conditions to merit selection
based on them; in addition, screening techniques devel-
oped based on LWP and OA were not cost effective in
sorghum breeding. Empirical screening based on impos-
ing drought at various growth stages and measuring plant
morphological and yield responses was the most effec-
tive approach. Long mesocotyl in seedling establishment
and recovery from mid-season stress after release by
rains are important traits that can be easily deployed in
lines. The stay-green trait has been well exploited to en-
hance post-flowering drought tolerance in sorghum [3].
At ICRISAT, growth-stage-specific breeding for drought
tolerance, which involves alternate seasons of screening
in specific drought and well-watered environments, has
been used to breed sorghum that can yield well in both
high-yield-potential environments as well as in drought-
prone environments [3]. Since hybrids have exhibited
relatively better performance than open pollinated (OP)
cultivars for grain yield under water-limited environ-
ments, hybrid cultivar development (including their par-
ents) should be given strategic importance for enhancing
sorghum production in water-scarce environments [3].
The progress in enhancing drought tolerance in sorghum
through conventional approaches is limited by the quan-
titative inheritance of drought tolerance and yield cou-
pled with the complexity of the timing, severity and du-
ration of drought. Biotechnology appears to offer prom-
ising tools, such as marker-assisted selection, for genetic
enhancement of drought tolerance in sorghum. Four sta-
ble and major QTLs were identified for the stay-green
trait and are being introgressed through MAS into elite
genetic backgrounds at ICRISAT, QDPI, Purdue Univer-
sity, and Texas A & M University [3].
Integration of the sorghum genetic map developed
from QTL information with the physical map will greatly
facilitate the map-based cloning and precise dissection of
complex traits such as drought tolerance in sorghum.
Sorghum has a compact genome size (2n = 20) and can
be an excellent model for identifying genes involved in
drought tolerance to facilitate their use in other crops. It
was reported that with respect to withstanding drought,
sorghum has four copies of a regulatory gene that acti-
vates a key gene family which is present in a wide vari-
ety of plants. Sorghum also has several genes for proteins
called expansins, which may be involved in helping sor-
ghum to recover from droughts. In addition, it has 328
cytochrome P450 genes, which may help plants respond
to drought stress, whereas rice has only 228 of these
genes [5].
Some of the drought tolerant sources identified in sor-
ghum at ICRISAT include Ajabsido, B35, BTx623,
BTx642, BTx3197, El Mota, E36Xr16 8/1, Gadambalia,
IS12568, IS22380, IS12543C, IS2403C, IS3462C, CSM-
63, IS11549C, IS12553C, IS12555C, IS12558C, IS17459C,
IS3071C, IS6705C, IS8263C, ICSV 272, Koro Kollo,
KS19, P898012, P954035, QL10, QL27, QL36, QL41,
SC414-12E, Segaolane, TAM422, Tx430, Tx432, Tx2536,
Tx2737, Tx2908, Tx7000 and Tx7078 (www.icrisat.org).
ICRISAT has identified lines that are tolerant to drought
at various growth stages (Table 5). Drought tolerance of
M 35-1, a highly popular post-rainy season adapted land-
race in India, has been amply demonstrated [41].
4. Hybrid Parents with Postrainy Season
Adaptation
Post-rainy sorghums are very crucial for food and fodder
security in the drought prone areas of India [43] as there
is no alternative cereal grown during this season, which
receives only 8% of the total annual rainfall. Due to ex-
cellent grain quality, post-rainy sorghums are mostly
used as food. The grain productivity of post-rainy sor-
ghum is very low as much of the cultivated area is under
landraces that are poor grain yielders. Terminal drought
stress is a major production constraint in the post-rainy
season as the crop is grown on receding soil moisture
after cessation of the rains. Low levels of heterosis for
grain yield and low levels of shoot fly resistance were
Table 5. Sorghum germplasm and breeding lines tolerant to
drought at specific growth stages, ICRISAT-Patancheru,
India.
Growth stage Drought tolerant sources/improved lines
Seedling emergence
IS 4405, IS 4663, IS 17595 and IS 1037,
VZM1-B and 2077 B, IS 2877, IS 1045, D
38061, D 38093, D 38060, ICSV 88050, ICSV
88065 and SPV 354
Early seedling ICSB 3, ICSB 6, ICSB 11 and ICSB 37, ICSB
54 and ICSB 88001
Mid-season
DKV 1, DKV 3, DKV 7, DJ 1195, ICSV 272,
ICSV 273, ICSV 295, ICSV 378, ICSV 572,
ICSB 58 and ICSB 196
Terminal droughtE 36-1, DJ 1195, DKV 3, DKV 4, DKV 17,
DKV 18, ICSB 17
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Copyright © 2011 SciRes. AJPS
596
observed in post-rainy season hybrids. Therefore, most
farmers use either landraces or open pollinated varieties
(OPVs) for Post-rainy season sowings [44]. Considering
that photo- period sensitivity and low temperature toler-
ance during flowering, terminal drought tolerance, and
grain quality traits are critical for post-rainy season crop,
ICRISAT is engaged in developing hybrid parents by
involving several post-rainy season adapted landraces (M
35-1, Gidda Maldandi, DSH 128, E 36-1, Barsizoot,
Dagadi Sholapur, Dagadi local, Amaravathi local, M
35-1 selection bulks, etc.) and elite varieties and B-lines
with good grain quality traits in the crossing program.
Promising B-lines with higher yield and good grain qual-
ity were developed (Table 6).
5. Grain Micronutrient Density
Biofortification (increasing the grain Fe and Zn status
through genetic means) complements the on-going ef-
forts to address hidden malnutrition which is rampant in
Sub-Saharan Africa and South Asia [45,46]. It is one of
the cheapest and sustainable options to combat the mal-
nutrition in predominantly sorghum eating populations
[47]. Based on sorghum grain consumption levels, nutria-
ent retention in grain storage and processing, and nutrient
bioavailability ICRISAT targeted 70 ppm Fe and 40 ppm
Zn contents in grain for addressing micronutrient malnu-
trition in populations who depend predominantly on sor-
ghum for their nutrient requirements [47]. ICRISAT un-
Table 6. Performance of post-rainy sorghum advanced B-lines in sorghum (A1-cytoplasm based) at ICRISAT, Patancheru
during 2009 postrainy season.
S. No Entry Days to 50% floweringPlant height (m)Grain luster score*Grain yield (t·ha–1) 100 grain weight (g)
1 SP 54457-1 74 1.5 2.0 6.3 3.2
2 SP 93037 81 1.3 2.0 5.6 2.3
3 SP 92919 72 1.4 2.0 5.0 2.6
4 SP 92931 73 1.4 2.0 4.7 2.7
5 SP 92929 76 1.1 2.0 4.7 2.5
6 SP 93035 79 1.3 2.0 4.7 2.4
7 SP 92927 72 1.4 2.0 4.6 2.7
8 SP 92925 73 1.3 2.0 4.4 2.6
9 SP 92923 72 1.4 2.0 4.4 2.6
10 SP 92939 76 1.2 2.0 4.4 2.6
11 SP 54425-1 74 1.3 3.0 4.3 3.3
12 SP 92921 72 1.4 2.0 4.2 2.5
13 SP 93019 71 1.2 2.7 3.5 3.3
14 ICSB 52 (Check) 71 1.5 3.0 5.0 4.0
15 296 B (Check) 79 1.1 3.0 3.4 3.0
Mean 74 1.3 2.2 4.6 2.8
CV 1.3 4.5 6.6 10.9 5.5
LSD 2 0.1 0.3 0.8 0.3
PVALUE 0 0 0 0 0
(*Luster score taken on a scale where 1 = highly lustrous and 5 = dull grain color). Small quantities of all these materials can be obtained from ICRISAT on
equest. r
Recent Advances in Sorghum Genetic Enhancement Research at ICRISAT597
dertook screening of core germplasm accessions to iden-
tify lines with high Fe and Zn contents. A total of 2267
core germplasm accessions were screened and promising
donors identified under the HarvestPlus Challenge Pro-
gramme [48]. Significant positive association between
grain Fe and Zn contents and no significant association
between grain Fe and Zn contents and agronomic traits
were observed [49]. ICRISAT is developing the hybrid
parents with high grain Fe and Zn contents in order to
develop and disseminate sorghum hybrids with high mi-
cronutrient density. A total of 66 commercial sorghum
cultivars developed by public sector and private sector
partner organizations in India were assessed for grain Fe
and Zn contents and promising cultivars identified [47]
(Table 7).
6. Sweet Sorghum for Ethanol Andanimal
Feed
Sweet sorghum is a multi-purpose crop that yields food,
fodder and fuel. It is being used for syrup and ethanol
production in U.S.A (http://nssppa.org/Sweet_Sorghum_
FAQs.html verified on 12th July 2011) EU (http://esse-
community.eu/ verified on 12th July 2011), China, Phil-
ippines, Mali, India and other countries. ICRISAT, under
its BioPower strategy is working on sweet sorghum im-
provement for bioethanol production without unduly
compromising the food or fodder use of the crop. Ethanol
feedstock CSH 22SS, the first sweet sorghum hybrid
released in India, was based on the ICRISAT-bred fe-
male parent ICSA 38. Strategic research at Indian na-
tional program and ICRISAT indicated that ethanol pro-
duction in Indiausing sweet sorghum is cost-effective and
its cultivation gives 23% additional income to farmers
compared to the grain sorghum [50]. There are minimal
food-fuel tradeoffs in sweet sorghum but season-speci-
ficity exists. Hybrids are the cultivar options, as hybrids
are high-yielding, flower early and less photoperiod-
sensitive compared to the varieties. ICRISAT, along with
Table 7. Mean performance of the commercial sorghum cultivars (Set I) for grain Fe and Zn contents at ICRISAT-
Patancheru, India during 2008 and 2009 postrainy seasons.
Fe content (mg·kg–1) Zn content (mg·kg–1)
Hybrid name Seed source 2008 2009 Mean 2008 2009 Mean
NSH 703 Nuziveedu Seeds, Hyderabad 50 38 44 36 28 32
GK 4035 Ganga Kaveri Seeds, Hyderabad 57 31 44 46 19 33
Mahabeej 703 MSSCL, Akola 53 33 43 36 22 29
NSH 702 Nuziveedu Seeds, Hyderabad 49 37 43 37 28 32
8562 Bayer Bio Sc., Hyderabad 51 31 41 37 23 30
Mahabeej 704 MSSCL, Akola 48 31 40 34 19 26
KDSH 1179 Krishidhan Seeds, Jalna 48 30 39 31 22 27
BSH 45 Biostadt Mh Seeds, Aurangabad 48 29 39 32 22 27
Madhura-SS hybrid Nimbkar Seeds, Paltan 52 25 39 43 21 32
Mahabeej 7 MSSCL, Akola 52 25 39 33 18 26
GK 4009 Ganga Kaveri Seeds, Hyderabad 46 30 38 36 17 27
Hi-jowar 52 Biostadt Mh Seeds, Aurangabad 42 33 38 28 22 25
PSV 2 (variety) ARS, Palem 47 28 38 36 16 26
CSH 25 MAU, Parbhani 53 27 37 35 19 25
8340 Bayer Bio Sc., Hyd 47 27 37 29 20 25
KDSH 209 Krishidhan Seeds, Jalna 48 28 36 31 22 26
PSV 1 (variety) ARS, Palem 47 26 36 31 17 24
BSH 47 Biostadt Mh seeds, Aurangabad 42 28 35 26 19 23
GK 4044 Ganga Kaveri Seeds, Hyderabad 43 26 33 32 16 22
8568 Bayer Bio Sc., Hyderabad 37 23 30 29 17 23
Controls
PVK 801 (variety) 55 30 43 41 20 30
CSH 16 (hybrid) 50 32 41 34 22 28
Mean 48 29 39 34 20 27
SE + 2.86 1.85 2.76 2.09 1.44 2.00
CD (5%) 8.39 5.27 7.84 6.13 4.10 5.68
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Recent Advances in Sorghum Genetic Enhancement Research at ICRISAT
598
Table 8. Nitrogen, neutral detergent fiber (NDF), in vitro digestibility (all in % of dry matter) and mega joule (MJ) of me-
tabolizable energy content and voluntary feed intake and changes in live weight in bulls fed a marketed commercial sorghum
stover-based feed block (CF B), an experimental swee t sorghum bagasse/stripped leave s-based feed block (SLB) and sorghum
stover of the type used in the CFB.
Diets Nitrogen (%)NDF (%) Iv Dig. (%) ME (MJ/kg)Intake (kg/d)Intake (g/d/kg LW) Weight changes (kg/d)
CFB 1.81a 56.1a 57.5a 8.21a 7.31a 35a 0.82a
SLB 1.65b 56.2a 54.6b 7.77b 7.52a 37a 0.73a
Sorghum stover 0.45c 70.2b 50.5b 7.30b 2.31b 13b –0.38b
its partners, is working on sweet sorghum ethanol value
chain development including the supply chain manage-
ment through a combination of centralized and decen-
tralized models for commercial ethanol production [51].
Sweet sorghum when fed directly as forage was found to
have high daily intake and higher digestibility in large
ruminants (cows and buffaloes) [52]. No significant dif-
ferences were observed in the intake or body weight of
animals when bagasse and stripped leaves feed blocks
were used to feed the ruminants indicating that sweet
sorghum bagasse (after extraction of juice) can be used
as animal feed without chemical or physical upgrading
(Table 8) [53].
7. Future Plans
In addition to the biotic and abiotic challenges, presumed
climate change effects influence the sorghum area and its
importance globally. Climate change will modify the
length of the growing period across the sorghum regions,
but this can be mitigated by the re-targeting and re-de-
ployment of existing germplasm. Predicted temperature
increases, through their effect on increasing rate of crop
development, will have greater negative impact on crop
production than the relatively small (±10%) changes in
rainfall that are predicted to occur. Yield gap analyses at
ICRISAT and elsewhere have shown that the negative
impacts of climate change can be largely mitigated
through greater adoption of improved crop, soil and wa-
ter management innovations by farmers and better tar-
geted crop improvement approaches by researchers, more
explicitly focused on adaptation to climate change.
Keeping all these points in view, crop improvement re-
search in sorghum need to beoriented towards genetic and
cytoplasmic diversification for high yield and large grain,
striga, shoot fly and grain mold resistance, drought, acid
soil and salinity tolerance, postrainy season adaptation,
sweet stalk traits, and grain micronutrient density. The
grain and stover quality attributes need special attention
in sorghum improvement programs to enhance the mar-
ket value. More collaboration is required between IC-
RISAT and NARS partners across the globe in this en-
deavor. Harnessing the synergies of public- and private-
sector agencies assume higher importance to ensure bet-
ter impacts of genetic enhancement in farmers’ fields.
REFERENCES
[1] B. V. S. Reddy, A. A. Kumar and P. S. Reddy, “Recent
Advances in Sorghum Improvement Research at ICRI-
SAT,” Kasetsart Journal: Natural Science, Vol. 44, 2010,
pp. 499-506.
[2] B. V. S. Reddy, A. A. Kumar, S. Ramesh and P. S. Reddy,
“Breeding Sorghum for Coping with Climate Change,” In:
S. S. Yadav, R. Redden, J. L. Hatfield and H. Lotze-
Campen, Eds., Crop Adaptation to Climate Change, John
Wiley & Sons Inc., Iowa, 2011, pp. 326-339.
[3] Z. Z. Nagy, F. Tuba, Z. Soldos and L. Erdei, “CO2-Ex-
change and Water Relation Responses of Sorghum and
Maize during Water and Salt Stress,” Journal of Plant
Physiology, Vol. 145, No. 4, 1995, pp. 539-544.
[4] B. V. S. Reddy, S. Ramesh, P. S. Reddy and A. A. Kumar,
“Genetic Enhancement for Drought Tolerance in Sor-
ghum,” Plant Breeding Reviews, Vol. 31, 2009, pp.
189-222. doi:10.1002/9780470593783.ch3
[5] A. H. Paterson, J. E. Bowers and R. Bruggmann, “The
Sorghum bicolor Genome and the Diversification of
Grasses,” Nature, Vol. 457, 2009, pp. 551-556.
doi:10.1038/nature07723
[6] A. H. Paterson, “The Weediness of Wild
Plants—Molecular Analysis of Genes Influencing Dis-
persal and Persistence of Johnson Grass, Sorghum Hale-
pense (l) pers,” Proceedings of the National Academy of
Sciences of the United States of America, Vol. 92, 1995,
pp. 6127-6131. doi:10.1073/pnas.92.13.6127
[7] P. Cooper, K. P. C. Rao, P. Singh, J. Dimes, P. S. Traore,
K. Rao, P. Dixit and S. J. Twomlow, “Farming with Cur-
rent and Future Climate Risk: Advancing a ‘Hypothesis
of Hope’ for Rainfed Agriculture in the Semi-Arid Trop-
ics,” E-Journal of SAT Agricultural Research, Vol. 7, No.
1, 2009.
[8] ICRISAT Strategic Plan to 2020, “Inclusive Market-
Oriented Development for Smallholder Farmers in the
Tropical Drylands,” International Crops Research Insti-
tute for the Semi-Arid Tropics (ICRISAT), Patancheru,
2010, p. 60.
[9] M. C. S. Bantilan, U. K. Deb, C. L. L. Gowda, B. V. S.
Reddy, A. B. Obilana and R. E. Evenson, “Sorghum Ge-
netic Enhancement Research Process, Dissemination and
Impacts,” International Crops Research Institute for the
Semi-Arid Tropics, Patancheru, 2004, p. 320.
[10] ICRISAT, “Medium-Term Plan 1994-1998,” Interna-
tional Crops Research Institute for the Semi-Arid Tropics,
Patancheru, 1992.
Copyright © 2011 SciRes. AJPS
Recent Advances in Sorghum Genetic Enhancement Research at ICRISAT599
[11] A. B. Obilana, E. S. Monyo and S. C. Gupta, “Impact of
Genetic Improvement in Sorghum and Pearl Millet: De-
veloping Country Experiences,” Proceedings of the In-
ternational Conference on Genetic Improvement of Sor-
ghum and Pearl Millet, Lubbock, 22-27 September 1996,
pp. 119-141.
[12] B. V. S. Reddy, A. A. Kumar, P. S. Reddy and M.
Elangovan, “Sorghum Germplasm: Diversity and Utiliza-
tion,” In: B. V. S Reddy, S. Ramesh, A. A. Kumar and C.
L. L. Gowda, Eds., Sorghum Improvement in the New
Millennium, International Crops Research Institute for the
Semi-Arid Tropics, Patancheru, 2008, pp. 153-169.
[13] S. A. Eberhart, P. J. Bramel-Cox and K. E. Prasada Rao,
“Preserving Genetic Resources,” Proceedings of the
International Conference on Genetic Improvement of
Sorghum and Pearl Millet, Lubbock, 22-27 September
1996, pp. 25-41.
[14] B. V. S. Reddy, H. C. Sharma, R. P. Thakur, S. Ramesh
and A. A. Kumar, “Characterization of ICRISAT-Bred
Sorghum Hybrid Parents,” International Sorghum and
Millets Newsletter, Vol. 48, Special Issue, 2007, pp.
1-123.
[15] H. C. Sharma, V. R. Bhagwat and P. G. Padmaja, “Tech-
niques to Screen Sorghums for Resistance to Insect
Pests,” In: B. V. S. Reddy, S. Ramesh, A. A. Kumar and
C. L. L. Gowda, Eds., Sorghum Improvement in the New
Millennium, International Crops Research Institute for the
Semi-Arid Tropics, Patancheru, 2008, pp. 31-49.
[16] R. P. Thakur, B. V. S. Reddy, S. Indira, V. P. Rao, S. S.
Navi, X. B. Yang and S. Ramesh, “Sorghum Grain
Mold,” International Crops Research Institute for the
Semi-Arid Tropics, Patancheru, No. 72, 2006, p. 32.
[17] K. F. Schertz and D. R. Pring, “Cytoplasmic Male Steril-
ity Systems in Sorghum,” Sorghum in the Eighties, In: L.
R. House, L. K. Mughogho and J. M. Peacock, eds., In-
ternational Crops Research Institute for the Semi-Arid
Tropics, Patancheru, 1982, pp. 373-383.
[18] K. F. Schertz, A. Sotomayor-Rios and S. Torres-Cardona,
“Cytoplasmic-Nuclear Male Sterility: Opportunities in
Breeding and Genetics,” Proceedings of Grain Sorghum
Reseasrch Utility Conference, Vol. 16, 1989, pp. 175-
186.
[19] T. Nagur, “Studies on Fertility Restoration and Combin-
ing Ability in Relation to Genetic Diversity and Cyto-
plasmic Constitution in Sorghum,” Ph.D. Dissertation,
Tamil Nadu Agricultural University, Coimbatore, 1971.
[20] K. F. Schertz, S. Sivaramakrishnan, W. W. Hanna, J.
Mullet, Y. Sun, U. R. Murty, D. R. Pring, K. N. Rai and
B. V. S. Reddy, “Alternate Cytoplasms and Apomixes of
Sorghum and Pearl Millet,” Proceedings of International
Conference on Genetic Improvement of Sorghum and
Pearl Millet, Lubbock, 22-27 September 1996, pp.
213-223.
[21] N. G. P. Rao, D. P. Tripathi and B. S. Rana, “Genetic
Analysis of Cytoplasmic Systems in Sorghum,” Indian
Journal of Human Genetics, Vol. 44, 1984, pp. 48-49.
[22] J. V. Worstell, H. J. Kidd and K. C. Schertz, “Relation-
ships among Male Sterility Inducing Cytoplasms of Sor-
ghum,” Crop Science, Vol. 24, No. 1, 1984, pp. 186-189.
doi:10.2135/cropsci1984.0011183X002400010044x
[23] G. W. Xu, Y. X. Cui, K. F. Schertz and G. E. Hart, “Iso-
lation of Mitochondrial DNA Sequences That Distinguish
Male-Sterility Inducing Cytoplasms in Sorghum bicolor
(L.) Moench,” Theoretical and Applied Genetics, Vol. 90,
No. 7-8, 1995, pp. 1180-1187. doi:10.1007/BF00222941
[24] K. F. Nwanze, “Screening for Resistance to Sorghum
Shoot Fly,” In: H. C. Sharma, F. Singh and K. F. Nwanze,
Eds., Plant Resistance to Insects in Sorghum, Interna-
tional Crops Research Institute for the Semi-Arid Tropics,
Patancheru, 1997, pp. 35-37.
[25] B. V. S. Reddy, P. Rao and U. K. Deb, “Global Sorghum
Genetic Enhancement Processes at ICRISAT,” In: M. C.
S. Bantilan, U. K. Deb, C. L. L. Gowda, B. V. S. Reddy,
A. B. Obilana and R. E. Evenson, Eds., Sorghum Genetic
Enhancement: Research Process, Dissemination and Im-
pacts, International Crops Research Institute for the
Semi-Arid Tropics, Patancheru, 2004, pp. 65-102.
[26] B. V. S. Reddy, S. Ramesh, P. S. Reddy and A. A. Kumar,
“Comparison of A1 and A2 Cytoplasmic Male-Sterility for
Combining Ability in Sorghum (Sorghum bicolor (L.)
Moench),” Indian Journal of Genetics and Plant Breed-
ing, Vol. 69, No. 3, 2009, pp. 199-204.
[27] A. A. Kumar, B. V. S. Reddy, H. C. Sharma and B.
Ramaiah, “Shoot Fly (Atherigona soccata) Resistance in
Improved Grain Sorghum Hybrids,” E-Journal of SAT
Agricultural Research, Vol. 6, No. 1, 2008.
[28] K. Satish, G. Srinivas, R. Madhusudhana, P. G. Padmaja,
R. N. Reddy, S. M. Mohan and N. Seetharama, “Identi-
fication of Quantitative Trait Loci for Resistance to Shoot
Fly in Sorghum [Sorghum bicolor (L.) Moench],” Theo-
retical and Applied Genetics, Vol. 119, No. 8, 2009, pp.
1425-1439. doi:10.1007/s00122-009-1145-8
[29] R. Bandyopadhyay, L. K. Mughogho and K. E. Prasada
Rao, “Sources of Resistance to Sorghum Grain Molds,”
Plant Disease, Vol. 72, 1988, pp. 504-508.
doi:10.1094/PD-72-0504
[30] R. Bandyopadhyay, J. W. Stenhouse, S. D. Singh and B.
V. S. Reddy, “Sorghum Grain Mold: Current Status,” In:
C. L. L. Gowda and J. W. Stenhouse, eds., Strengthening
Sorghum Research Collaboration in Asia: Report of the
Asian Sorghum Scientists Meeting, International Crops
Research Institute for the Semi-Arid Tropics, Patancheru,
1998, pp. 19-21.
[31] A. A. Kumar, B. V. S. Reddy, R. P. Thakur and B.
Ramaiah, “Improved Sorghum Hybrids with Grain Mold
Resistance,” E-Journal of SAT Agricultural Research,
Vol. 6, No. 1, 2008.
[32] F. R. Bidinger, G. L. Hammer and R. C. Muchow, “The
Physiological Basis of Genotype by Environment Interac-
tion in Crop Adaptation,” In: M. Cooper and G. L. Ham-
mer, Eds., Plant Adaptation and Crop Improvement, CAB
International, Wallingford, 1996, pp. 329-347.
[33] B. V. S. Reddy, B. Ramaiah and A. A. Kumar, “Evalua-
tion of Sorghum Genotypes for Stay-Green Trait and
Grain Yield,” E-Journal of SAT Agricultural Research,
Copyright © 2011 SciRes. AJPS
Recent Advances in Sorghum Genetic Enhancement Research at ICRISAT
Copyright © 2011 SciRes. AJPS
600
Vol. 3 (Suppl. 1), 2007.
[34] B. V. S. Reddy,“Genetic Improvement for Drought Resis-
tance in Sorghum: A Plant Breeder’s Viewpoint,” Genetic
Improvement for Drought Resistance, Proc. Discussion
Series of Drought Research Seminar Forums. ICRISAT,
Patancheru, 1986. pp. 28-32.
[35] A. Blum, J. Mayer and G. Golan, “Agronomic and Physi-
ological Assessments of Genotypic Variation for Drought
Resistance in Sorghum,” Australian Journal of Agricul-
ture Research, Vol. 40, 1989, pp. 49-61.
doi:10.1071/AR9890049
[36] R. C. Muchow, F. R. Bidinger and G. L. Hammer, “Tar-
geting Sorghum Improvement in Drought-Prone Envi-
ronments: Approaches and Progress,” In: Proceedings of
the International Conference on Genetic Improvement of
Sorghum and Pearl Millet, Lubbock, 1996, pp. 429-442.
[37] I. G. Haussmann, A. B. Obilana and A. Blum, “Hybrid
Performance of Sorghum and Its Relationship to Morpho-
logical and Physiological Traits under Variable Drought
Stress in Kenya,” Plant Breeding, Vol. 117, No. 3, 1998,
pp. 223-229. doi:10.1111/j.1439-0523.1998.tb01930.x
[38] A. K. Borrell, G. L. Hammar and R. O. Henzell, “Does
Maintaining Green Leaf Area in Sorghum Improve Yield
under Drought? II. Dry Matter Production and Yield,”
Crop Science, Vol. 40, No. 4, 2000a, pp. 1037-1048.
doi:10.2135/cropsci2000.4041037x
[39] A. K. Borrell, G. L. Hammar and A. C. L. Douglas,
“Does Maintaining Green Leaf Area in Sorghum Improve
Yield under Drought? I. Leaf Growth and Senescence,”
Crop Science, Vol. 40, No. 4, 2000b, pp. 1026-1037.
doi:10.2135/cropsci2000.4041026x
[40] K. Harris, P. K. Subudhi and A. Borrell, “Sorghum Stay
Green QTL Individually Reduce Post-Flowering Drou
ght-Induced Leaf Senescence,” Journal of Experimental
Botany, Vol. 58, No. 2, 2007, pp. 327-338.
doi:10.1093/jxb/erl225
[41] N. Seetharama, B. V. S. Reddy and J. M. Peacock,
“Sorghum Improvement for Drought Resistance in Crops
with Emphasis on Rice,” International Rice Research
Institute (IRRI), Manila, 1982, pp. 317-338.
[42] ICRISAT, Annual Report, 1981, ICRISAT, Patancheru,
1982, pp. 1-31.
[43] Anonymous, Progress Report 2000-2001, Development
of hybrids, Rabi sorghum (NATP MM project), Group
meeting, Hyderabad, 16-18 October 2001, pp 11-14.
[44] P. S. Reddy, B. V. S. Reddy and A. A. Kumar, “M 35-1
Derived Sorghum Varieties for Cultivation during the
Postrainy Season,” E-Journal of SAT Agricultural
Research, Vol. 7, No. 1, 2009.
[45] J. V. Meenakshi, N. L. Johnson, V. M. Manyong, H.
Degroote, J. Javelosa, D. R. Yanggen, F. Naher, C. G. J.
Garcia and E. Meng, “How Cost-Effective Is Bioforti-
fication in Combating Micronutrient Malnutrition? An ex-
ante Assessment,” World Development Report, Vol. 38,
No. 1, 2010, pp. 64-75.
doi:10.1016/j.worlddev.2009.03.014
[46] H. E. Bouis, C. Hotz, B. McClafferty, J. V. Meenakshi
and W. H. Pfeiffer, “Biofortification: A New Tool to Re-
duce Micronutrient Malnutrition,” Food and Nutrition
Bulletin, Vol. 32, Supplement 1, 2011, pp. 31S-40S.
[47] A. A. Kumar, B. V. S. Reddy, K. L. Sahrawat and B.
Ramaiah, “Combating Micronutrient Malnutrition: Identi-
fication of Commercial Sorghum Cultivars with High
Grain Iron and Zinc,” E-Journal of SAT Agricultural Re-
search, Vol. 8, No. 1, 2010.
[48] A. A. Kumar, B. V. S. Reddy, B. Ramaiah, P. Sanjana
Reddy, K. L. Sahrawat and H. D. Upadhyaya,“Genetic
Variability and Plant Character Association of Grain Fe
and Zn in Selected Core Collections of Sorghum
Germplasm and Breeding Lines,” E-Journal of SAT
Agricultural Research, Vol. 7, No. 1, 2009.
[49] P. S. Reddy, B. V. S. Reddy, A. A. Kumar, S. Ramesh, K.
L. Sahrawat and P. V. Rao, “Association of Grain Fe and
Zn Contents with Agronomic Traits in Sorghum,” Indian
Journal of Plant Genetic Resources, Vol. 23, No. 3, 2010,
pp. 280-284.
[50] B. V. S. Reddy, S. Ramesh, A. A. Kumar, S. P. Wani, R.
Ortiz, H. Ceballos and T. K. Sreedevi, “Bio-Fuel Crops
Research for Energy Security and Rural Development in
Developing Countries,” Bio-Energy Research, Vol. 1, No.
3-4, 2008, pp. 248-258. doi:10.1007/s12155-008-9022-x
[51] A. A. Kumar, B. V. S. Reddy, C. R. Reddy, M. Blümmel,
P. S. Rao, B. Ramaiah and P. S. Reddy, “Enhancing the
Harvest Window for Supply Chain Management of Sweet
Sorghum for Ethanol Production,” E-Journal of SAT Ag-
ricultural Research, Vol. 8, No. 1, 2010.
[52] A. A. Kumar, B. V. S. Reddy, M. Blümmel, S. Anandan,
Y. R. Reddy, C. R. Reddy, P. S. Rao and P. S. Reddy,
“On-Farm Evaluation of Elite Sweet Sorghum Genotypes
for Grain and Stover Yields and Fodder Quality,” Animal
Nutrition and Feed Technology, Vol. 10S, 2010, pp 69-
78.
[53] M Blümmel, S. S. Rao, S. Palaniswami, L. Shah and B. V.
S. Reddy, “Evaluation of Sweet Sorghum (Sorghum bi-
color (L) Moench) Used for Bio-Ethanol Production in
the Context of Optimizing Whole Plant Utilization,”
Animal Nutrition and Feed Technology, Vol. 9, 2009, pp.
1-10.