STUDIES ON INDUCED MUTATIONS FOR MORPHOLOGICAL, YIELD AND YIELD CONTRIBUTING TRAITS IN MUNGBEAN (Vigna radiata (L.) Wilczek)
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Date
2021-12-06
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Acharya N.G. Ranga Agricultural University, Guntur
Abstract
The present investigation entitled “Studies on induced mutations for
morphological, yield and yield contributing traits in mungbean (Vigna radiata (L.)
Wilczek)” was carried out during kharif, 2017 (M1 generation), rabi, 2017-18 (M2
generation), kharif, 2018 (M3 generation) and rabi, 2018-19 (M4 generation) at dry
land farm of Sri Venkateswara Agricultural College, Tirupati.
The present investigation was under taken to induce mutations in two
mungbean varieties viz., WGG-42 and LGG-460 and to determine the effectiveness
and efficiency of various mutagens at different doses/concentrations of gamma rays
(200 Gy, 300 Gy, 400 Gy, 500 Gy and 600 Gy), EMS (0.2%, 0.3%, 0.4%, 0.5% and
0.6%) and SA (1 mM, 2 mM and 3 mM). The study was also aimed to estimate the
nature of variability, trait associations, direct and indirect contributions of various
yield component character towards yield in mutant populations and to isolate
desirable mutants for yield and yield component traits.
The results on LD50 values of various mutagens based on seed germination
percentage revealed that, the LD50 value for gamma rays in WGG-42 was 565.63 Gy
and in LGG-460 it was 448.33 Gy. Similarly, the LD50 value for EMS in WGG-42
was 0.46% and in LGG-460 it was 0.42%. Whereas, the LD50 value for SA in
WGG-42 was 2.72 mM and in LGG-460 it was 2.01 mM.
In M1 generation under laboratory condition, the mean values for
germination percentage (%), shoot length (cm) and root length (cm) showed a
decreasing trend with increasing dose/concentrations of the mutagens in both the
genotypes. The reductions in all these characters were found to be more prominent
in SA treatments followed by EMS and gamma rays treatments. Similarly under
field condition most of the traits were greatly reduced due to mutagenic treatments.
The reductions in all these characters were found to be more prominent in SA
treatments followed by EMS and gamma rays treatments. The variety WGG-42 was
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found more sensitive than LGG-460 variety to gamma rays, EMS and SA
treatments.
In M2 generation, 376 progenies of WGG-42 and 379 progenies of LGG-460
selected in M1 were studied. Three types of chlorophyll mutants viz., albina, xantha
and chlorina were observed and occurrence of chlorina was found to be the most
frequent. Viable mutants like stature, leaf, duration, cotelydonary leaf, pod, seed
size, seed colour and purple colour stem and non viable mutants like non-flowered
sterile, flowered sterile and chimeric mutants were identified which could be
exploited for improving desirable traits into the otherwise well adopted cultivars.
The EMS treatments were found to be more effective and efficient in inducing
chlorophyll and viable mutants than gamma rays in both the varieties. Data on
eleven quantitative traits showed a wide range of variation and shift in mean values
in both positive and negative directions for most of the traits in mutants, which
indicated great scope for improving various quantitative traits through mutation
breeding.
In M3 generation 394 progenies of WGG-42 and 248 progenies of LGG-460,
selected in M2 based on superior performance in yield and yield component traits,
were studied for yield and yield component traits. High GCV and PCV were
observed for number of primary branches per plant, number of clusters per plant,
number of pods per plant, pod length and seed yield per plant in both mutant
populations. High heritability coupled with high genetic advance as per cent of mean
was observed for number of clusters per plant, number of pods per plant and seed
yield per plant indicating the preponderance of additive gene action and hence
simple selection would be more effective for improvement of these characters.
In M4 generation, a total of 55 mutants i.e., 36 from WGG-42 and 19 from
LGG-460, which were selected in M3 were evaluated along with their parents. The
mutant lines of WGG-42 viz., WGG-42-15, WGG-42-10, WGG-42-12, WGG-42-5,
WGG-42-25, WGG-42-33 and WGG-42-29 and the mutant lines of LGG-460 viz.,
LGG-460-2, LGG-460-19, LGG-460-12, LGG-460-16, LGG-460-8 and LGG-460-3
showed the high per se performance for seed yield per plant suggesting that these
mutant lines could be exploited directly for improving yield. The highest 100 seed
weight was registered by the mutant line WGG-42-10 followed by WGG-42-28,
WGG-42-15 and LGG-460-17, which could be exploited in the hybridization
programme as donors for improving bold seeded types. High GCV and PCV was
observed for number of primary branches per plant, number of clusters per plant and
number of pods per plant indicating the presence of wider variation in mutant lines
and high heritability estimates were also recorded for all the eleven characters. High
heritability coupled with high genetic advance as per cent of mean was recorded for
plant height, number of primary branches per plant, number of clusters per plant,
number of pods per plant, pod length and seed yield per plant.
Character association analysis revealed that the characters viz., days to 50%
flowering, days to maturity, plant height, number of primary branches per plant,
number of clusters per plant, number of pods per plant, number of seeds per pod,
pod length and 100 seed weight exhibited significant positive association with seed
yield per plant. Among these traits number of pods per plant and 100 seed weight
had the high and moderate positive direct effects, respectively on seed yield per
plant and hence suggested more weightage to these traits in the selection programme
to isolate superior lines with high genetic potentiality for seed yield per plant.
Description
STUDIES ON INDUCED MUTATIONS FOR
MORPHOLOGICAL, YIELD AND YIELD
CONTRIBUTING TRAITS IN MUNGBEAN
(Vigna radiata (L.) Wilczek)