Genetic Diversity Analysis and Validation of Microsatellite Markers Linked with Tolerance to Powdery Mildew Disease in Mungbean [Vigna radiata (L.) Wilczek

Abstract

Background: Mungbean [Vigna radiata (L.) Wilczek] is a self-pollinated diploid grain legume (2n=2x=22) crop and has a genome size of 560 Mb. The present study was concentrate to portray the nature and extent of genotypic variation exists among mungbean collections for a range of traits of potential agronomic and adaptive interests. Many diseases affect mungbean, causes the major constraint in the increasing production among which Powdery mildew disease caused by Erisyphepolygoni is economically significant because it reduces photosynthetic activity and physiological changes which results in 20-40 per cent reduction in yield. Some gene-specific marker were analysed and found associated with powdery mildew resistance in mungbean genotypes.Methods: The present investigation was carried out to evaluate thirty-one mungbean genotypes (including four checks) collected from the different parts of India. The genotypes were sown in an incomplete augmented bock design along with four checks varieties. viz. ‘Kamdev’, ‘OBBGG-52’, ‘IPM-02-14’ and ‘IPM-02-3’. All the mungbean genotypes were evaluated for different phenotypic traits and their tolerance to powdery mildew disease at two cropping seasons as well as at two different locations in Odisha. In this investigation, seven molecular markers viz., VrCSSTS1, VrCSSTS2, VrCSSSR3, CEDG191, MB-SSR238, CEDG166, CEDG282 were analysed.Result: SSR marker such as VrCSSSR and VrCSSTS linked with powdery mildew resistance gene were tested in different genotypes with known powdery mildew reaction and the results showed a consistent association of the marker in all the powdery mildew resistant genotypes and absent in all the powdery mildew susceptible genotypes. The results confirmed the validation of these markers with the powdery mildew resistance gene in different genetic backgrounds. Similarly, CEDG191, CEDG166, CEDG282 markers, reported to be linked to powdery mildew resistance, amplified the respective marker fragment of 100 to 300 bp in mungbean genotypes and were polymorphic. The above PCR-based and locus-specific markers could be employed for marker-assisted breeding (MAB) program as well as genotype conservation. These linked markers will boost the efficiency and precision of powdery mildew resistance breeding in mungbean.