Molecular characterization and validation of microsatellite markers linked with tolerance to Powdery Mildew disease in mungbean (Vigna radiata (L.) Wilczek)
Loading...
Date
2018
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Orissa University of Agriculture and Technology, Bhubaneswar
Abstract
Mungbean (Vigna radiata L. Wilczek) is a self-pollinated diploid grain legume
(2n=2x=22) crop and has genome size of 560 mb. It is the most important legume (Pulse) crop
after Chickpea and Pigeon pea in India and widely cultivated in different parts of India as it is well
adapted to multiple cropping systems in the drier and warmer climates.The yield of mungbean in
India was 30.41 lakh hectares with a total production of 14.24 lakh tonnes and Odisha in particular
is very low productivity (337 kg/ha) mainly due to inherent genotype failures and losses due to
pests and diseases. On account of its dense crop canopy, photo insensitivity, and short duration, it
assumes special significance in crop diversification, intensification, and conservation of natural
resources and sustainability of production systems. Many diseases affect mungbean, among which
Powdery mildew disease in mungbean caused by Erisyphe polygoni is economically important
and it reduces photosynthetic activity and physiological changes which results in 20-40 per cent
reduction in yield. For achieving a gain in yield and for developing resistant and well adoptable
genotypes through breeding programme, scientific collection, characterisation and evaluation of
mungbean germplasm is highly essential. It also helps proper identification of genotypes with the
desired characteristics. The objective of the present study was to describe the nature and extent of
genotypic variation among mungbean collections for a range of traits of potential agronomic and
adaptive interests. A total of 27 mungbean genotypes along with four check varieties viz.
‘Kamdev’, ‘OBBGG-52’, ‘IPM-02-14’ and ‘IPM-02-3’,wereevaluated for several diverse traits
for two cropping seasons at two different locations in Odisha. Analysis of data on classification of
visual character and various categorical DUS descriptors revealed the occurrence of 62 numbers
of variants out of which eighteen variants could not be observed in any of the genotype. Seed
colour was observed in different states of colour like yellow, green, mottled and black exhibited in
9.67%, 41.93%, 29.03%, 19.35% genotypes respectively. Majority of genotypes (22.58%) were
highly resistant for powdery mildew and 16.12% were resistant to powdery mildew. While
19.35% genotypes exhibited were highly susceptible, with moderate resistance and susceptible.
Among all genotypes 3.3%vgenotypes were exhibited susceptible to powdery mildew. The cluster
analysis revealed wide diversity in the mungbean collection. The genotype pairs ‘Badahana Local’
and ‘Hinjili Local’, showed the maximum dissimilarity (2.67) followed by dissimilarity between
‘OBGG-52’ and ‘Berhampur Local 1’ among the thirty one genotypes, whereas, ‘Nayagarh
Local’ and ‘Nayagarh Local 6’ showed lowest dissimilarity (0.01) followed by dissimilarity
between ‘Kukudakhandi Local’ and ‘Banpur Local’(0.20).The genetic dis-similarity matrix was
analysed using UPGMA clustering algorithms for the construction of dendrogram and the analysis
revealed four main clusters at 8.75 dis-similarity coefficient with best possible discrimination
between groups. Fourteen genotypes were included in Cluster I whereas cluster-II was represented
by only one genotype (‘Sambalpur Local 2’). Ten genotypes were represented in the Cluster III
and cluster IV had 6 genotypes. At 8.07 dis-similarity coefficient, Cluster-I was further subdivided
into two sub-clusters. The sub-cluster I A was represented by two genotypes and subcluster
IB had 12 genotypes. In the present study analyzed seven molecular markers viz.,
VrCSSTS1, VrCSSTS2, VrCSSSR3, CEDG191, MB-SSR238, CEDG166, CEDG282 were
found associated with powdery mildew resistance in mungbean genotypes studied. The VrCSSSR
and VrCSSTS marker linked with powdery mildew resistance gene were tested in different
genotypes with known powdery mildew reaction and the results showed consistent association of
the marker in all the powdery mildew resistant genotypes and absent in all the powdery mildewsusceptible
genotypes. The results confirmed the validation of these markers with powdery
mildew resistance gene in different genetic back-grounds. Similarly, CEDG191, CEDG166,
CEDG282 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) programme as
well as genotype conservation. These linked markers will boost the efficiency and precision of
powdery mildew resistance breeding in mungbean.
Description
Th-5227
Keywords
null