Isolation, characterization and selection of indigenous Bradyrhizobium strains with outstanding symbiotic performance to increase soybean yields in Mozambique.
Isolation, characterization and selection of indigenous Bradyrhizobium strains with outstanding symbiotic performance to increase soybean yields in Mozambique.
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DOI：
10.1016/j.agee.2017.06.017
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发表时间：
2017-08-01
期刊：
影响因子：
--
通讯作者：
Hungria M
中科院分区：
文献类型：
--
作者：
Chibeba AM;Kyei-Boahen S;Guimarães MF;Nogueira MA;Hungria M
生物固氮（BNF）是非洲大豆生产的关键过程。选择非洲本土大豆慢生根瘤菌优良菌株是一个可行的策略。从莫桑比克的大豆根瘤中获得了 87 个分离株。分离株适合慢生根瘤菌 (75%) 和农杆菌-根瘤菌 (25%) 进化枝。获得了5株具有优异共生性能的慢生根瘤菌分离株。大豆接种有效的根瘤菌菌株使得热带地区无需使用氮肥。一个经常报道的问题是接种菌株未能克服本土根瘤菌种群带来的竞争。筛选已经适应当地条件的本土根瘤菌，寻找用作接种剂的高效菌株，是克服接种失败的一个有前途的策略。本研究的目的是分离和表征本土根瘤菌，并鉴定在莫桑比克农业气候条件下有可能纳入大豆生产接种剂配方的菌株，包括混杂和非混杂大豆品种。从 15 个地点种植的混杂大豆根瘤中获得的总共 105 个分离株以及 5 个商业菌株在温室中进行了固氮效果筛选。 87 个分离株证实能够在大豆上形成有效根瘤，并用于通过 rep-PCR (BOX) 和 16S rRNA 基因测序进行遗传表征，并用于共生有效性。 BOX-PCR 指纹分析显示出显着的遗传多样性，形成了 41 个簇，相似度为 65%。 16S rRNA 分析将分离株归属慢生根瘤菌属 (75%) 和农杆菌/根瘤菌属 (25%)。在莫桑比克本土根瘤菌中检测到共生有效性存在很大差异，其中 10 个分离株的性能优于商业菌株 B. diazoefficiens USDA 110（最佳参考菌株），而 51 个分离株的性能低于所有参考菌株。在第二次温室试验中，对第一次温室试验中的 13 个最佳分离株以及 5 个商业菌株在两个混杂（TGx 1963-3F 和 TGx 1835-10E）和一个非混杂（BRS 284）大豆品种中进行了评估。一般来说，杂种大豆对接种反应更好。 13 株分离株还具有体外对酸度和碱度（pH 分别为 3.5 和 9.0）、盐度（0.1、0.3 和 0.5 mol L−1 NaCl）和高温（35、40 和 45 °C）的耐受性。五个分离株，其中三个（Moz 4、Moz 19 和 Moz 22）属于 B. elkanii 超进化枝，另外两个（Moz 27 和 Moz 61）属于 B. japonicum 超进化枝，始终表现出高共生有效性，表明接种适应当地条件的本土根瘤菌是提高莫桑比克大豆产量的一种可能策略。 MLSA 使用 4 个蛋白质编码管家基因 dnaK、glnII、gyrB 和 recA 确认了 5 个精英分离株的系统发育位置。
Biological nitrogen fixation (BNF) is a key process for soybean production in Africa. The selection of elite African indigenous soybean Bradyrhizobium strains is a feasible strategy. Eighty-seven isolates were obtained from soybean nodules in Mozambique. Isolates fit into the Bradyrhizobium (75%) and Agrobacterium-Rhizobium (25%) clades. Five Bradyrhizobium isolates with outstanding symbiotic performance were obtained. Soybean inoculation with effective rhizobial strains makes unnecessary the use of N-fertilizers in the tropics. A frequently reported problem is the failure of the inoculant strains to overcome the competition imposed by indigenous rhizobial populations. The screening of indigenous rhizobia, already adapted to local conditions, searching for highly effective strains for use as inoculants represents a promising strategy in overcoming inoculation failure. The objective of this study was to isolate and characterize indigenous rhizobia and to identify strains that hold potential to be included in inoculant formulations for soybean production, with both promiscuous and non-promiscuous soybean cultivars, in Mozambican agro-climatic conditions. A total of 105 isolates obtained from nodules of promiscuous soybean grown at 15 sites were screened for N2-fixation effectiveness in the greenhouse along with five commercial strains. Eighty-seven isolates confirmed the ability to form effective nodules on soybean and were used for genetic characterization by rep-PCR (BOX) and sequencing of the 16S rRNA gene, and also for symbiotic effectiveness. BOX-PCR fingerprinting revealed remarkable genetic diversity, with 41 clusters formed, considering a similarity level of 65%. The 16S rRNA analysis assigned the isolates to the genera Bradyrhizobium (75%) and Agrobacterium/Rhizobium (25%). Great variability in symbiotic effectiveness was detected among the indigenous rhizobia from Mozambique, with ten isolates performing better than the commercial strain B. diazoefficiens USDA 110, the best reference strain, and 51 isolates with lower performance than all reference strains. Thirteen of the best isolates from the first greenhouse trial were evaluated, along with the five commercial strains, in two promiscuous (TGx 1963-3F and TGx 1835-10E) and one non-promiscuous (BRS 284) soybean cultivars in a second greenhouse trial. In general the promiscous soybeans responded better to inoculation. The 13 isolates were also characterized for tolerance to acidity and alkalinity (pH 3.5 and 9.0, respectively), salinity (0.1, 0.3 and 0.5 mol L−1 of NaCl) and high temperatures (35, 40 and 45 °C) in vitro. Five isolates, three (Moz 4, Moz 19 and Moz 22) belonging to the superclade B. elkanii and two (Moz 27 and Moz 61) assigned to the superclade B. japonicum, consistently showed high symbiotic effectiveness, suggesting that the inoculation with indigenous rhizobia adapted to local conditions represents a possible strategy for increasing soybean yields in Mozambique. Phylogenetic position of the five elite isolates was confirmed by the MLSA with four protein-coding housekeeping genes, dnaK, glnII, gyrB and recA.
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影响因子：
3.4
作者：
Duran, David;Rey, Luis;Ruiz-Argueeso, Tomas
通讯作者：
Ruiz-Argueeso, Tomas
影响因子：
4.9
作者：
AHERN, CR;BAKER, DE;AITKEN, RL
通讯作者：
AITKEN, RL
影响因子：
4.8
作者：
Abaidoo, R. C.;Keyser, H. H.;Sanginga, N.
通讯作者：
Sanginga, N.
DOI：
10.3763/ijas.2010.0548
发表时间：
2011-02-01
影响因子：
3.4
作者：
Giller, Ken E.;Murwira, Mazwita S.;Mpepereki, Sheunesu
通讯作者：
Mpepereki, Sheunesu
影响因子：
4.4
作者：
Groenemeyer, Jann L.;Kulkarni, Ajinkya;Reinhold-Hurek, Barbara
通讯作者：
Reinhold-Hurek, Barbara