Selection of efficient rhizobial symbionts forCratylia argentea in the cerrado biome

Ciência Rural

Cruz, José Carlos¹  Marriel, Ivanildo Evódio¹  Oliveira, Christiane Abreu de¹  Calazans, Giovanna Moura²  Matrangolo, Walter José Rodrigues¹ 

[1] Embrapa Milho e Sorgo (CNPMS, Sete Lagoas, Brazil;Fundação de Ensino Superior de Itabira (FUNCESI, Itabira, Brasil

关键词: biological fixation;    legumes;    cerrado;   

DOI  :  10.1590/0103-8478cr20151137

学科分类：农业科学（综合）

来源: Universidade Federal de Santa Maria * Centro de Ciencias Rurais

【 摘 要 】

: Cratylia argenteais a leguminous shrub native to the cerrado, which has great potential for forage production and recovery of degraded areas. This study aimed to isolate, characterize, and select efficient rhizobial strains in symbiosis with Cratylia argentea . Rhizobacteria were isolated from the nodules of 12-month-old plants and cultivated in pots containing cerrado soil. Twenty-five bacterial strains were obtained, which displayed extensive variability with respect to morphological and symbiotic characteristics. Cratylia argenteaseeds were planted in pots containing 5kg of cerrado soil and maintained in the greenhouse. The treatments consisted of 25 rhizobial isolates, two controls (without nitrogen and without inoculation), with or without nitrogen fertilization (5mgN·plant-1·week-1), and four replications. Plants were cultivated for 150 days after planting seeds to evaluate nodule number, nodule dry weight, shoot and root dry weight, shoot and root N content, and relative and symbiotic efficiency. Thirteen isolates improved shoot dry weight (up to 65.8%) and shoot nitrogen concentration (up to 76%) compared with those of control treatments. Two isolates, 4 (CR42) and 22 (CR52), conferred higher symbiotic efficiency values of approximately 20%. Therefore, these two rhizobial isolates displayed the highest potential as beneficial inoculants to optimize the symbiotic efficiency for Cratyliaand to increase the incorporation of nutrients and biomass into the productive system in the cerrado.

【 授权许可】

Unknown