Genetic Profiling and Diversity of Some Promising Efficient Rhizobial Isolates on Faba Bean Plants

Abstract

A group of twenty faba bean rhizobial isolates was collected from two Egyptian Governorates (Dakahlia and Damitta). The isolates were further morphologically and physiologically characterized to check their growth and symbiotic performance on faba bean plants. According to remarkable lab and pots tests, five rhizobial isolates (Rh 32, Rh 6-A, Rh 3-4, Rh RL3, and Rh 8-A) were selected and subjected to further biochemical and molecular characterizations. Genetic profiling of the five promising rhizobial isolates was conducted using six ISSR-primers. Amplification of bacterial genomic DNA produced a total of 37 genomic loci, 54% of them were polymorphic and 46% were monomorphic. The rate of polymorphism ranged between 25% to 80% with an average of 54%. Clustering pattern analysis of morphological and physiological data grouped the twenty rhizobial isolates in five clusters and the five selected rhizobial isolates were falling close to each other. Clustering analysis of ISSR data grouped the the five rhizobial isolates in four clusters. Analysis based on ISSR data revealed that the lowest genetic distance was 2.00 between Rh 6-A and Rh 3-4 isolates, while the highest genetic distance of 3.61 was between Rh 32 and each of Rh 6-A, Rh 3-4, and Rh RL3 isolates. The greatest similarity measurement was 0.931 between Rh 6-A and Rh 3-4 isolates; while the lowest similarity was 0.745 between Rh 32 and Rh 3-4 isolates. It can concluded that clustering pattern analysis based on molecular data could be used in facilitating the selection of rhizobial isolates that will be promising as a source of genes for biological nitrogen fixation and plant growth-promotion.

Phenotypic and Genetic Diversity of Native Rhizobium Isolated From Root Nodules of Leguminous Plants Grown in Reclaimed Soil, Egypt

“…Moreover, RAPD and ISSR markers, employed previously, explored the genetic variability among several wheat varieties and proved that the ISSR markers gave more frequency (El-Assal and Gaber, 2012). Fathy et al (2021) used the ISSR marker to study the genetic profiling of five rhizobial isolates. PCR produced 37 genomic loci, 54% of them polymorphic.…”

“…Therefore, the molecular criteria are more efficient in assessing genetic relationships among populations of rhizobia (Rai et al, 2012;Fetyan and Mansour, 2012). DNA markers, such as ISSR and RAPD, proved as excellent sources of diversity and establishing new genetic relationships (Randhawa et al, 2013;Etminan et al, 2016;Fathy et al, 2021). RAPD use is one of the quickest and easiest markers to discriminate Rhizobia on strains level (Rajasundari et al, 2009;Shoukry et al, 2013;Bhuyan et al, 2014;Flores-Félix et al, 2020).…”