Characterization and nodulation capacity of native bacteria isolated from mung bean nodules used as a trap plant in Brazilian tropical soils

2021 ◽  
Vol 167 ◽  
pp. 104041
Author(s):  
Vinício Oliosi Favero ◽  
Rita Hilário de Carvalho ◽  
Ana Beatriz Carneiro Leite ◽  
Karine Moura de Freitas ◽  
Jerri Édson Zilli ◽  
...  
2021 ◽  
Vol 11 ◽  
Author(s):  
Vinício Oliosi Favero ◽  
Rita Hilário Carvalho ◽  
Victória Monteiro Motta ◽  
Ana Beatriz Carneiro Leite ◽  
Marcia Reed Rodrigues Coelho ◽  
...  

The mung bean has a great potential under tropical conditions given its high content of grain protein. Additionally, its ability to benefit from biological nitrogen fixation (BNF) through association with native rhizobia inhabiting nodule microbiome provides most of the nitrogen independence on fertilizers. Soil microbial communities which are influenced by biogeographical factors and soil properties, represent a source of rhizobacteria capable of stimulating plant growth. The objective of this study is to support selection of beneficial bacteria that form positive interactions with mung bean plants cultivated in tropical soils, as part of a seed inoculation program for increasing grain yield based on the BNF and other mechanisms. Two mung bean genotypes (Camaleão and Esmeralda) were cultivated in 10 soil samples. Nodule microbiome was characterized by next-generation sequencing using Illumina MiSeq 16S rRNA. More than 99% of nodule sequences showed similarity with Bradyrhizobium genus, the only rhizobial present in nodules in our study. Higher bacterial diversity of soil samples collected in agribusiness areas (MW_MT-I, II or III) was associated with Esmeralda genotype, while an organic agroecosystem soil sample (SE_RJ-V) showed the highest bacterial diversity independent of genotype. Furthermore, OTUs close to Bradyrhizobium elkanii have dominated in all soil samples, except in the sample from the organic agroecosystem, where just B. japonicum was present. Bacterial community of mung bean nodules is mainly influenced by soil pH, K, Ca, and P. Besides a difference on nodule colonization by OTU sequences close to the Pseudomonas genus regarding the two genotypes was detected too. Although representing a small rate, around 0.1% of the total, Pseudomonas OTUs were only retrieved from nodules of Esmeralda genotype, suggesting a different trait regarding specificity between macro- and micro-symbionts. The microbiome analysis will guide the next steps in the development of an inoculant for mung bean aiming to promote plant growth and grain yield, composed either by an efficient Bradyrhizobium strain on its own or co-inoculated with a Pseudomonas strain. Considering the results achieved, the assessment of microbial ecology parameters is a potent coadjuvant capable to accelerate the inoculant development process and to improve the benefits to the crop by soil microorganisms.


1995 ◽  
Vol 94 (4) ◽  
pp. 629-634 ◽  
Author(s):  
Mohamed Benichou ◽  
Gracia Martinez-Reina ◽  
Felix Romojaro ◽  
Jean-Claude Pech ◽  
Alain Latche

2013 ◽  
Vol 27 (3) ◽  
pp. 239-246 ◽  
Author(s):  
A.E. Ajayi ◽  
M.S. Dias Junior ◽  
N. Curi ◽  
I. Oladipo

Abstract This study aimed to investigate the mineralogy, moisture retention, and the compressive response of two agricultural soils from South West Nigeria. Undisturbed soil cores at the A and B horizons were collected and used in chemical and hydrophysical characterization and confined compression test. X-ray diffractograms of oriented fine clay fractions were also obtained. Our results indicate the prevalence of kaolinite minerals relating to the weathering process in these tropical soils. Moisture retention by the core samples was typically low with pre-compression stress values ranging from50 to 300 kPa at both sites. Analyses of the shape of the compression curves highlight the influence of soil moisture in shifts from the bi-linear to S-shaped models. Statistical homogeneity test of the load bearing capacity parameters showed that the soil mineralogy influences the response to loading by these soils. These observations provide a physical basis for the previous classification series of the soils in the studied area. We showed that the internal strength attributes of the soil could be inferred from the mineralogical properties and stress history. This could assist in decisions on sustainable mechanization in a datapoor environment.


AGRICA ◽  
2019 ◽  
Vol 1 (2) ◽  
pp. 32-37
Author(s):  
Yustina M.S.W Puu ◽  
Hildegardis Nalti Nansi

Callosobruchus Chinensis is a pest that damages mung bean seeds in storage and causes damage to both the quality and quantity of seeds. This study aims to determine the effectiveness of neem leaf extracts in suppressing the development of the Callosobruchus Chinensis pest as one of the postharvest pests in the commodity green beans. This research conducted at the Laboratory of the Faculty of Agriculture, University of Flores, by using a Completely Randomized Design (CRD) with five treatments and three replications. The concentration of neem leaf extract treatment is 0 ml / l, 25 ml / l, 30 ml / l, 35 ml / l, and 40 ml / l. The results showed that the concentration of neem leaf extract 40 ml / l caused mortality of C. Chinensis imago as contact poison by 99% and nerve poison by 47%. While the effectiveness of the limb leaf extract on spawning activity was 86%.


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