Rhizobia, crucial for nitrogen fixation in leguminous plants, play a vital role in soybean cultivation. This study, conducted in Mexico, a major soybean importer, aimed to identify bacteria from nodules of five soybea...Rhizobia, crucial for nitrogen fixation in leguminous plants, play a vital role in soybean cultivation. This study, conducted in Mexico, a major soybean importer, aimed to identify bacteria from nodules of five soybean varieties in high-production regions. Multilocus sequence analysis (MLSA) was employed for enhanced species resolution. The study identified six Bradyrhizobium species: Bradyrhizobium japonicum USDA 110, Bradyrhizobium japonicum USDA 6, Bradyrhizobium elkanii USDA 76, Bradyrhizobium neotropicale, Bradyrhizobium lablabi, and Bradyrhizobium icense. Bradyrhizobium japonicum USDA 110 predominated in the soils, displaying symbiotic preference for the Huasteca 400 variety. However, phylogenetic analysis didn't reveal a clear association between strains, soil, and soybean variety. This research sheds light on the diversity of rhizobia in Mexican soybean cultivation, contributing to the understanding of symbiotic relationships in soybean production systems.展开更多
The cosmid gene library of Rhizobium fredii strain B52 genome was constructed,andthen a 3.7kb enhancing fragment was isolated through plant experiment,which could im-prove the symbiotic efficiency of Bradyrhizobium ja...The cosmid gene library of Rhizobium fredii strain B52 genome was constructed,andthen a 3.7kb enhancing fragment was isolated through plant experiment,which could im-prove the symbiotic efficiency of Bradyrhizobium japonicum strain 2210.The obtained higheffective strain was called HN32.It has been widely used as soybean inoculant in He-longjiang,Sichuan and Guangxi provinces with an average of 6%yield increase comparingwith 2210.The recombinant plasmid pHN32 in strain HN32 contains a 3.7kb foreign insert.Its nucleotide sequence was analyzed.Computer analysis indicated that there were two openreading frames(ORFs)within the 3.7kb enhancing fragment.ORF1 shows no homologywith known genes except the first 19 amino acids which had high homology with lactosetransferase of Agrobacterium radiobacter.ORF2 shows 54% homology with hupE of Rhizo-bium leguminosarum,and related with glycosylation transfer gene of Rhizobium meliloti.Names enfA and enfB are proposed to ORF1 and ORF2 respectively.展开更多
Soybean(Glycine max),the primary source of high-quality plant protein,plays a crucial role as a grain and oil crop in China.Harnessing the full potential of symbiotic nitrogen fixation in soybean production holds imme...Soybean(Glycine max),the primary source of high-quality plant protein,plays a crucial role as a grain and oil crop in China.Harnessing the full potential of symbiotic nitrogen fixation in soybean production holds immense significance for agriculture and ecology alike.Zhongdou 63,a newly developed early-maturing summer soybean cultivar in 2021,exhibits remarkable traits such as high yield,superior quality,multi-resistance,and wide adaptability.In this study,eight distinct rhizobia strains from diverse regions were meticulously screened to identify highly effective strains specifically suited for Zhongdou 63.The aboveground biomass,plant height,chlorophyll content,root length,nodule number,and nodule dry weight of Zhongdou 63 were measured and the data were subjected to statistical analysis.The results demonstrated that Y63-1 is a predominant strain of Zhongdou 63.Subsequently,we conducted further investigations on the broad-spectrum nodulation characteristics of Y63-1.Ten representative soybean cultivars were individually inoculated with Y63-1 and subsequently analyzed for nodule numbers and nodule dry weight in their symbiotic systems with rhizobia.The findings revealed that Y63-1 effectively formed nodules with all ten soybean varieties tested.In summary,our current study identified highly efficient broad-spectrum Bradyrhizobium elkanii strain Y63-1 as the predominant strain in Zhongdou 63 and provided a theoretical foundation for enhancing yield potential not only in Zhongdou 63 but also in other varieties through inoculation with highly efficient rhizobia in production.展开更多
文摘Rhizobia, crucial for nitrogen fixation in leguminous plants, play a vital role in soybean cultivation. This study, conducted in Mexico, a major soybean importer, aimed to identify bacteria from nodules of five soybean varieties in high-production regions. Multilocus sequence analysis (MLSA) was employed for enhanced species resolution. The study identified six Bradyrhizobium species: Bradyrhizobium japonicum USDA 110, Bradyrhizobium japonicum USDA 6, Bradyrhizobium elkanii USDA 76, Bradyrhizobium neotropicale, Bradyrhizobium lablabi, and Bradyrhizobium icense. Bradyrhizobium japonicum USDA 110 predominated in the soils, displaying symbiotic preference for the Huasteca 400 variety. However, phylogenetic analysis didn't reveal a clear association between strains, soil, and soybean variety. This research sheds light on the diversity of rhizobia in Mexican soybean cultivation, contributing to the understanding of symbiotic relationships in soybean production systems.
基金the High Technology Research and Development Programme of china.
文摘The cosmid gene library of Rhizobium fredii strain B52 genome was constructed,andthen a 3.7kb enhancing fragment was isolated through plant experiment,which could im-prove the symbiotic efficiency of Bradyrhizobium japonicum strain 2210.The obtained higheffective strain was called HN32.It has been widely used as soybean inoculant in He-longjiang,Sichuan and Guangxi provinces with an average of 6%yield increase comparingwith 2210.The recombinant plasmid pHN32 in strain HN32 contains a 3.7kb foreign insert.Its nucleotide sequence was analyzed.Computer analysis indicated that there were two openreading frames(ORFs)within the 3.7kb enhancing fragment.ORF1 shows no homologywith known genes except the first 19 amino acids which had high homology with lactosetransferase of Agrobacterium radiobacter.ORF2 shows 54% homology with hupE of Rhizo-bium leguminosarum,and related with glycosylation transfer gene of Rhizobium meliloti.Names enfA and enfB are proposed to ORF1 and ORF2 respectively.
基金funded by Key Research and Development Plan Projects of Hubei Province(2022BBA0036)the National Natural Science Foundation of China(grant no.32071964)。
文摘Soybean(Glycine max),the primary source of high-quality plant protein,plays a crucial role as a grain and oil crop in China.Harnessing the full potential of symbiotic nitrogen fixation in soybean production holds immense significance for agriculture and ecology alike.Zhongdou 63,a newly developed early-maturing summer soybean cultivar in 2021,exhibits remarkable traits such as high yield,superior quality,multi-resistance,and wide adaptability.In this study,eight distinct rhizobia strains from diverse regions were meticulously screened to identify highly effective strains specifically suited for Zhongdou 63.The aboveground biomass,plant height,chlorophyll content,root length,nodule number,and nodule dry weight of Zhongdou 63 were measured and the data were subjected to statistical analysis.The results demonstrated that Y63-1 is a predominant strain of Zhongdou 63.Subsequently,we conducted further investigations on the broad-spectrum nodulation characteristics of Y63-1.Ten representative soybean cultivars were individually inoculated with Y63-1 and subsequently analyzed for nodule numbers and nodule dry weight in their symbiotic systems with rhizobia.The findings revealed that Y63-1 effectively formed nodules with all ten soybean varieties tested.In summary,our current study identified highly efficient broad-spectrum Bradyrhizobium elkanii strain Y63-1 as the predominant strain in Zhongdou 63 and provided a theoretical foundation for enhancing yield potential not only in Zhongdou 63 but also in other varieties through inoculation with highly efficient rhizobia in production.
