Studies on induced mutations in mungbean [Vigna radiata (L.) Wilczek] and identification of MYMIV resistant mutants using molecular makers
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Date
2020-11
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CCSHAU, Hisar
Abstract
Mungbean (Vigna radiata L. Wilczek) is an economically important pulse crop of South-East Asia
It is mostly liked in Indian diets due to its good palatability, easy digestibility and high nutritional quality.
Unavailability of sufficient genetic variability is a major challenge for mungbean breeders. In this study,
dry seeds of two mungbean varieties viz., MH 2-15 and MH 318 were mutagenized by 300, 400, 500 Gy of
γ-rays and 0.2, 0.4 % EMS as well as their combination treatments and variability for various parameters
were studied in M1, M2 and M3 populations during 2017-18 at CCS HAU, Hisar. In M1 generation, seed
germination parameters like seed germination per cent, shoot and root length, seedling length, seedling
fresh and dry weight, SVI-I and II, mean germination rate, synchronization index, germination index,
coefficient of velocity of germination and speed of germination decreased whereas seed/seedling mortality,
mean germination time and days to 50 % germination increased with the increase in concentration of both
the mutagens under controlled lab and natural field conditions. LD50 values for γ-rays ranged from 488.47
to 694.28 Gy in MH 2-15 and 519.77 to 715.15 Gy in MH 318 and 0.35 to 0.69 % in MH 2-15 and 0.37 to
0.74 % in MH 318 for EMS under controlled lab and natural field conditions. The M2 population of 24,464
mutants were screened and a broad spectrum of chlorophyll mutants (1.08 %) like
xantha>viridis>chlorina>albina and morphological mutants (1.98 %) with compact, bushy, erect,
spreading, tall, dwarf nature, tetra-foliate, penta-foliate, elliptic, lanceolate, lobbed, wrinkled, round leaves,
early maturing, late maturing, sterile plants and large, small, lobbed pods were observed. Mutagen
exhibited non-linear reduction in effectiveness and efficiency with increase in concentration. Mutagenesis
generated significant variability in seed yield and attributing traits. Based on correlation and path
coefficient studies, number of pods plant-1, number of seeds pod-1 and 100-seed weight were observed to be
important parameters for increasing seed yield plant-1. Overall, MH 2-15 was found to be more sensitive for
mutagenic changes as compared to MH 318, whereas among mutagens, the combination treatments (γ-rays
+ EMS) have exhibited more shift in magnitude of all the parameters followed by EMS and γ-rays. In M3
generation, 64 MYMIV resistant mutants were identified with <1 % PDI through phenotypic screening
which were further confirmed by amplification of YMD linked SSR markers viz., YR4, CYR1 and
CEDG180. Twenty-two mutants were identified with true resistance based on marker assisted screening.