Author(s)

Khin Myat Soe^1*, Aung Zaw Htwe², Kyi Moe², Tomomi Abiko³, Takeo Yamakawa⁴

¹Biofertilizer Laboratory, Land Use Division, Department of Agriculture, Ministry of Agriculture, Livestock and Irrigation, Yangon, Myanmar.
²Department of Agronomy, Yezin Agricultural University, Yezin, Myanmar.
³Laboratory of Agroecology, Department of Bioresource Sciences, Faculty of Agriculture, Kyushu University, Harumachi, Kasuya-Machi, Kasuya-Gun, Fukuoka, Japan.
⁴Laboratory of Plant Nutrition, Department of Bioresource and Bioenvironmental Sciences, Faculty of Agriculture, Kyushu University, Motooka, Nishi-Ku, Fukuoka, Japan.

Black gram (Vigna mungo L. Hepper) is one of the main leguminous crops that provide chief source of food. Several Bradyrhizobium species are able to induce effective nodules in black gram cultivars. In the present study, we characterized forty isolates of indigenous black gram bradyrhizobia from Myanmar based on the sequence analysis of the bacterial 16S rRNA gene. The sequence analysis confirmed that all isolates were categorized and identified as the genus Bradyrhizobium and they were conspecific with B. elkanii, B. sp., B. liaoningense, B. japonicum and B. yunamingense. Almost all the collected isolates from major black gram growing regions of Nyaunglebin Bago Regio, Chaungzon Mon State, Sittwe Rakhine State, Danubyu Ayeyarwady Region and Launglon Tanintharyi Region were identified as B. liaoningense. At Danubyu Ayeyarwady Region and Pyinmanar Nay Pyi Taw Region, most of the strains were identified as B. japonicum. On the other hand, more or less all the isolates from Launglon Tanintharyi Region and Hpa-an Kayin State were related to B. elkanii. However, all B. sp. strains were found in Salingyi Sagaing Region black gram growing region. This is the first report describing Bradyrhizobium strains that were isolated from soil samples of major black gram growing areas in Myanmar. Evaluation of the effectiveness of Myanmar Bradyrhizobim strains isolated from soil samples of major black gram growing areas of Myanmar for plant growth and nitrogen fixation was studied in pot experiments with completely randomized design and three replicates. The nodule dry weight, shoot dry weight and acetylene reduction activity of the plant inoculated with Bradyrhizobium elkanii LauBG38 were significantly higher in ARA per plant, nodule and shoot dry weights than the other tested isolates in both Yezin-4 and Yezin-7 black gram varieties. We expect that Myanmar Bradyrhizobium elkanii LauBG38 will be able to use as Biofertilizer for black gram cultivars.

Black Gram, Myanmar, 16S rRNA Gene, Bradyrhizobium, Nitrogen Fixation

Soe, K.M., Htwe, A.Z., Moe, K., Abiko, T. and Yamakawa, T. (2020) Phylogenetic Diversity and Evaluation the Effectiveness of Indigenous Bradyrhizobium Strains for Myanmar Black Gram (Vigna mungo L. Hepper) Cultivars. American Journal of Plant Sciences, 11, 285-306. doi: 10.4236/ajps.2020.112022.