Genetic diversity of soybean-nodulating rhizobia in Nepal in relation to climate and soil properties

Adhikari, Dinesh; Kaneto, Masakazu; Itoh, Kazuhito; Suyama, Kousuke; Pokharel, Bhanu Bhakta; Gaihre, Yam Kanta

doi:10.1007/s11104-012-1134-6

Cited by 56 publications

(54 citation statements)

References 40 publications

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“…In the present study, B. yuanmingense strains were isolated from the root nodule of soya bean from Yangon Region and Shan State. Additionally, this strain was also isolated from soya bean in China 32 , Nepal 33 , and Thailand 29 . The phylogenetic tree showed that the indigenous bradyrhizobial strains were distributed throughout the soya bean growing regions of Myanmar.…”

Section: Discussionmentioning

confidence: 99%

Phylogenetic diversity of indigenous soya bean bradyrhizobia from different agro-climatic regions in Myanmar

Soe¹,

Yamakawa²,

Hashimoto³

et al. 2013

ScienceAsia

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Soya bean (Glycine max Merr.) is the most important legume crop in the world and an important cash crop in Myanmar. In the present study, we characterized 43 isolates of indigenous soya bean rhizobia from Myanmar based on the sequence analysis of the bacterial 16S-23S rRNA internal transcribed spacer region. The sequence analysis confirmed that all isolates were categorized and identified as the genus Bradyrhizobium and they were conspecific with B. japonicum, B. elkanii, B. yuanmingense, and Bradyrhizobium sp. The highest genetic diversity of Bradyrhizobium strains was observed in the Shan State soya bean growing area. B. elkanii was distributed throughout the cultivation areas and was recorded as the dominant soya bean-nodulating strain in Myanmar. The present study revealed that there were two Rj-genotypes as Rj4-and non-Rj-genotypes among the collected soya bean cultivars from Myanmar. These findings indicate a high compatibility between Rj4-genotypes soya beans and nodulation type B strains in Shan State and Yangon region. In Mandalay region, the compatibility between non-Rj-genotype soya beans and nodulation type A strains was clearly investigated. This is the first report describing B. yuanmingense from nodules of soya bean and the geographical distribution of indigenous bradyrhizobia of soya bean from different regions in Myanmar.

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Section: Discussionmentioning

confidence: 99%

Phylogenetic diversity of indigenous soya bean bradyrhizobia from different agro-climatic regions in Myanmar

Soe¹,

Yamakawa²,

Hashimoto³

et al. 2013

ScienceAsia

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“…B. liaoningense T indeed failed to nodulate any of the local plant varieties tested in our cross-inoculation experiment. Also, the rather pH-neutral soils which were sampled might be relevant for lack of B. liaoningense (61), since it is assumed that B. canariense and B. liaoningense tolerate acidic and prefer alkaline soils, respectively (22,63). The broad range of soil pHs at our sampling sites indicates that this might not be the only crucial factor.…”

Section: Pachyrhizimentioning

confidence: 98%

Rhizobia Indigenous to the Okavango Region in Sub-Saharan Africa: Diversity, Adaptations, and Host Specificity

Grönemeyer

Kulkarni

Hölscher

et al. 2014

Appl Environ Microbiol

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The rhizobial community indigenous to the Okavango region has not yet been characterized. The isolation of indigenous rhizobia can provide a basis for the formulation of a rhizobial inoculant. Moreover, their identification and characterization contribute to the general understanding of species distribution and ecology. Isolates were obtained from nodules of local varieties of the pulses cowpea, Bambara groundnut, peanut, hyacinth bean, and common bean. Ninety-one of them were identified by BOX repetitive element PCR (BOX-PCR) and sequence analyses of the 16S-23S rRNA internally transcribed spacer (ITS) and the recA, glnII, rpoB, and nifH genes. A striking geographical distribution was observed. Bradyrhizobium pachyrhizi dominated at sampling sites in Angola which were characterized by acid soils and a semihumid climate. Isolates from the semiarid sampling sites in Namibia were more diverse, with most of them being related to Bradyrhizobium yuanmingense and Bradyrhizobium daqingense. Host plant specificity was observed only for hyacinth bean, which was nodulated by rhizobia presumably representing yet-undescribed species. Furthermore, the isolates were characterized with respect to their adaptation to high temperatures, drought, and local host plants. The adaptation experiments revealed that the Namibian isolates shared an exceptionally high temperature tolerance, but none of the isolates showed considerable adaptation to drought. Moreover, the isolates' performance on different local hosts showed variable results, with most Namibian isolates inducing better nodulation on peanut and hyacinth bean than the Angolan strains. The local predominance of distinct genotypes implies that indigenous strains may exhibit a better performance in inoculant formulations.T he catchment area of the Okavango River extends across parts of the three sub-Saharan African countries of Angola, Namibia, and Botswana and is mainly characterized by smallholder and subsistence farming. Since cultivation techniques remain underdeveloped, e.g., in terms of irrigation and the application of agrochemicals or rhizobial inoculants, local farmers are confronted with low yields and decreasing soil fertilities (1). Pulses like cowpea (Vigna unguiculata), Bambara groundnut (Vigna subterranea), peanut (Arachis hypogaea), hyacinth bean (Lablab purpureus), and common bean (Phaseolus vulgaris) are cultivated and occasionally intercropped, but natural nodulation rates are often low (2), presumably due to a seasonal reduction of the rhizobial population caused by drought and heat. Thus, nitrogen input via symbiotic N 2 fixation might be very limited.Field-grown cowpea plants in Ghana have been reported to fix more than 200 kg N/ha (89% of plant N) (3). In contrast, values of only 4 to 29 kg N-fixed/ha (15 to 56% of plant N) were observed in semiarid southwestern Zimbabwe (4). In such areas, the application of a rhizobial inoculant may thus hold the potential to increase plant nutrition and soil fertility. Many effective rhizobial strains have been identif...

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“…As to the rhizobia, soil pH and salinity are the main ecological factors determining their distribution (10,11), while agricultural practices, such as crop management (12), tillage intensity (13)(14)(15)(16), fertilization (17), legume cultivation history (18,19), and land use patterns (3), can also modify rhizobial diversity and abundance.…”

mentioning

confidence: 99%

Abundance and Diversity of Soybean-Nodulating Rhizobia in Black Soil Are Impacted by Land Use and Crop Management

Yan

Han

et al. 2014

Appl Environ Microbiol

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To investigate the effects of land use and crop management on soybean rhizobial communities, 280 nodule isolates were trapped from 7 fields with different land use and culture histories. Besides the known Bradyrhizobium japonicum, three novel genospecies were isolated from these fields. Grassland (GL) maintained a higher diversity of soybean bradyrhizobia than the other cultivation systems. Two genospecies (Bradyrhizobium spp. I and III) were distributed widely in all treatments, while Bradyrhizobium sp. II was found only in GL treatment. Cultivation with soybeans increased the rhizobial abundance and diversity, except for the soybean monoculture (S-S) treatment. In monoculture systems, soybeans favored Bradyrhizobium sp. I, while maize and wheat favored Bradyrhizobium sp. III. Fertilization decreased the rhizobial diversity indexes but did not change the species composition. The organic carbon (OC) and available phosphorus (AP) contents and pH were the main soil parameters positively correlated with the distribution of Bradyrhizobium spp. I and II and Bradyrhizobium japonicum and negatively correlated with Bradyrhizobium sp. III. These results revealed that different land uses and crop management could not only alter the diversity and abundance of soybean rhizobia, but also change interactions between rhizobia and legume or nonlegume plants, which offered novel information about the biogeography of rhizobia.

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Genetic diversity of soybean-nodulating rhizobia in Nepal in relation to climate and soil properties

Cited by 56 publications

References 40 publications

Phylogenetic diversity of indigenous soya bean bradyrhizobia from different agro-climatic regions in Myanmar

Phylogenetic diversity of indigenous soya bean bradyrhizobia from different agro-climatic regions in Myanmar

Rhizobia Indigenous to the Okavango Region in Sub-Saharan Africa: Diversity, Adaptations, and Host Specificity

Abundance and Diversity of Soybean-Nodulating Rhizobia in Black Soil Are Impacted by Land Use and Crop Management

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