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 aim of this research was to assess the diversity of the Cameroon cotton zone in soybean associated rhizobia in order to formulate the most efficient elite inoculant to boost both the cotton and soybean production....The aim of this research was to assess the diversity of the Cameroon cotton zone in soybean associated rhizobia in order to formulate the most efficient elite inoculant to boost both the cotton and soybean production. Therefore, soybean associated rhizobia were isolated and characterized morphologically, physiologically and biochemically on YEMA culture media. For each of the two soybean varieties (Houla1 and TGX1910 14F) used, the trials were laid out in two IRAD-fields of North Cameroon (Sanguere-Paul) and Far-North (Soukoundou) respectively, under a complete randomized complete block design, the isolate formulations representing the treatments. The six isolated strains (IS1, IS2, IS3, IS4, IS5, IS6) from which seven liquid inoculant were formulated were revealed to belong to the same slow growing group of rhizobia, with a high level of tolerance to temperature, pH, and salinity, with optimum growth at respectively 28˚C, pH (7 - 9), salt (1% - 5%). Not surprisingly, root nodules were formed by both inoculated and uninoculated soybean plants. However, the most efficient soybean-rhizobia symbiosis for nodulations were isolate IS6 associated to TGX1910 14F variety, and isolate IS5 associated to Houla1variety at Sanguere-Paul. Whereas isolate M was associated to TGX1910 14F variety, Houla 1 variety had affinity with native rhizobia isolates at Soukoundou. The present results suggest the adaptability of rhizobia isolates to a particular soybean variety at a particular cotton fields zone. These findings should be taken into consideration for commercial inoculant formulation.展开更多
Two-year field experiments were carried out at El-Kassasen Horticultural Research Station, Agricultural Research Center (ARC), Ismailia government, Egypt, during 2018 and 2019 summer seasons to evaluate some soybean c...Two-year field experiments were carried out at El-Kassasen Horticultural Research Station, Agricultural Research Center (ARC), Ismailia government, Egypt, during 2018 and 2019 summer seasons to evaluate some soybean cultivars for interplanting with mandarin trees to achieve high productivity of both crops, land usage and profitability under sandy soil conditions. The treatments were the combinations of two cropping systems (interplanting and solid cultures) and five soybean cultivars (Giza 21, Giza 22, Giza 35, Giza 82 and Giza 111). A strip plot design with three replications was used. Interplanting soybean cultivar Giza 22 with mandarin trees gave a higher total count of rhizobia in rhizosphere of mandarin roots after 75 days from soybean sowing than the other treatments in both seasons. The highest fruit weight and volume, total soluble solids (T.S.S.), fruit yields per tree and per ha were obtained by growing soybean cultivar Giza 22 or Giza 111 with mandarin compared with the other treatments in both seasons. With respect to soybean crop, interplanting soybean with mandarin trees decreased percentages of light intensity at the middle and bottom of the plant, chlorophylls a and b, as well as, plant dry weight after 75 days from soybean sowing compared with those of solid culture in both seasons. Soybean cultivars Giza 22 and Giza 82 had higher light intensity at the middle and bottom of the plant, as well as chlorophyll a, meanwhile soybean cultivars Giza 22 and Giza 111 had higher plant dry weight than the other soybean cultivars after 75 days from soybean sowing in both seasons. Soybean cultivar Giza 22 and Giza 111 had higher plant dry weight than the other soybean cultivars under interplanting and solid plantings in both seasons. Interplanting soybean with mandarin trees decreased soybean seed yield and its attributes compared with soybean solid culture in both seasons. Soybean cultivars Giza 111 and Giza 22 gave a higher number of pods per plant, seed yields per plant and per ha than the other cultivars in both seasons. Soybean cultivars Giza 111 and Giza 22 followed by Giza 82 recorded a higher number of pods per plant, seed yields per plant and per ha under interplanting and solid cultures than the other treatments in both seasons. Interplanting soybean cultivar Giza 22 and Giza 111 with mandarin trees achieved higher LER, LEC, total return and MAI than solid culture of mandarin. Growing four ridges of soybean cultivars Giza 22 or Giza 111 between mandarin trees cultivar Fremont had higher productivity, land usage and profitability than mandarin solid culture under sandy soil conditions.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.
文摘The aim of this research was to assess the diversity of the Cameroon cotton zone in soybean associated rhizobia in order to formulate the most efficient elite inoculant to boost both the cotton and soybean production. Therefore, soybean associated rhizobia were isolated and characterized morphologically, physiologically and biochemically on YEMA culture media. For each of the two soybean varieties (Houla1 and TGX1910 14F) used, the trials were laid out in two IRAD-fields of North Cameroon (Sanguere-Paul) and Far-North (Soukoundou) respectively, under a complete randomized complete block design, the isolate formulations representing the treatments. The six isolated strains (IS1, IS2, IS3, IS4, IS5, IS6) from which seven liquid inoculant were formulated were revealed to belong to the same slow growing group of rhizobia, with a high level of tolerance to temperature, pH, and salinity, with optimum growth at respectively 28˚C, pH (7 - 9), salt (1% - 5%). Not surprisingly, root nodules were formed by both inoculated and uninoculated soybean plants. However, the most efficient soybean-rhizobia symbiosis for nodulations were isolate IS6 associated to TGX1910 14F variety, and isolate IS5 associated to Houla1variety at Sanguere-Paul. Whereas isolate M was associated to TGX1910 14F variety, Houla 1 variety had affinity with native rhizobia isolates at Soukoundou. The present results suggest the adaptability of rhizobia isolates to a particular soybean variety at a particular cotton fields zone. These findings should be taken into consideration for commercial inoculant formulation.
文摘Two-year field experiments were carried out at El-Kassasen Horticultural Research Station, Agricultural Research Center (ARC), Ismailia government, Egypt, during 2018 and 2019 summer seasons to evaluate some soybean cultivars for interplanting with mandarin trees to achieve high productivity of both crops, land usage and profitability under sandy soil conditions. The treatments were the combinations of two cropping systems (interplanting and solid cultures) and five soybean cultivars (Giza 21, Giza 22, Giza 35, Giza 82 and Giza 111). A strip plot design with three replications was used. Interplanting soybean cultivar Giza 22 with mandarin trees gave a higher total count of rhizobia in rhizosphere of mandarin roots after 75 days from soybean sowing than the other treatments in both seasons. The highest fruit weight and volume, total soluble solids (T.S.S.), fruit yields per tree and per ha were obtained by growing soybean cultivar Giza 22 or Giza 111 with mandarin compared with the other treatments in both seasons. With respect to soybean crop, interplanting soybean with mandarin trees decreased percentages of light intensity at the middle and bottom of the plant, chlorophylls a and b, as well as, plant dry weight after 75 days from soybean sowing compared with those of solid culture in both seasons. Soybean cultivars Giza 22 and Giza 82 had higher light intensity at the middle and bottom of the plant, as well as chlorophyll a, meanwhile soybean cultivars Giza 22 and Giza 111 had higher plant dry weight than the other soybean cultivars after 75 days from soybean sowing in both seasons. Soybean cultivar Giza 22 and Giza 111 had higher plant dry weight than the other soybean cultivars under interplanting and solid plantings in both seasons. Interplanting soybean with mandarin trees decreased soybean seed yield and its attributes compared with soybean solid culture in both seasons. Soybean cultivars Giza 111 and Giza 22 gave a higher number of pods per plant, seed yields per plant and per ha than the other cultivars in both seasons. Soybean cultivars Giza 111 and Giza 22 followed by Giza 82 recorded a higher number of pods per plant, seed yields per plant and per ha under interplanting and solid cultures than the other treatments in both seasons. Interplanting soybean cultivar Giza 22 and Giza 111 with mandarin trees achieved higher LER, LEC, total return and MAI than solid culture of mandarin. Growing four ridges of soybean cultivars Giza 22 or Giza 111 between mandarin trees cultivar Fremont had higher productivity, land usage and profitability than mandarin solid culture under sandy soil conditions.
文摘为了促进广谱高效大豆埃氏慢生根瘤菌Y63-1菌株的高效生产与推广应用,本研究对其培养基进行了筛选与优化。首先比较了Y63-1在YMA、TY、SM、PA和BSE 5种根瘤菌基本培养基中的生长速度,结果表明Y63-1在TY基本培养基中生长最快。以TY为基本培养基进行单因素碳源及无机盐利用试验,结果表明葡萄糖是Y63-1生长的最佳碳源,CaCl_(2)为必要的培养基成分,Rh微量元素对菌株的生长有很大的促进作用。进一步对蛋白胨、葡萄糖、酵母粉及Rh微量元素4种组分进行正交优化,获得了适宜Y63-1生长的最佳培养基,配方(1 L)为:8 g蛋白胨、10 g葡萄糖、3 g酵母粉、0.1 g CaCl_(2)·6H_(2)O、3 mL Rh微量元素,pH7.0。此培养基也能显著提升USDA110的生长速率,可以广泛应用于慢生根瘤菌菌剂的大规模生产。
