Studies on induced genetic variation for yield, disease resistance and quality traits in hard and soft wheat (Triticum aestivum L.)
Loading...
Date
2022-12-24
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
CSK HPKV, Palampur
Abstract
Present study was undertaken with the objectives to assess the efficacy of physical mutagens, chemical
mutagens and their combinations and to estimate induced genetic variation and identify putative mutants
for yield, yellow rust, powdery mildew resistance and quality traits. Experiment was conducted at the
Rice and Wheat Research Centre, Malan during Rabi 2021-22. Experimental material comprised of two
promising cultivars of bread wheat [Triticum aestivum (L.)] viz. HPW 89 (soft) and HPW 251 (hard).
Experimental materials also included a total of ninety M2 mutant lines of wheat varieties HPW 251 and
HPW 89. For working out mutagenic effectiveness and efficiency, both wheat varieties were subjected
to mutagenesis by using EMS (0.3%, 0.6% and 0.9%), gamma-rays (250 Gy, 300 Gy and 350 Gy) and
their combinations. HPW 89 exhibited higher reduction in germination percentage under lab conditions
in comparison to HPW 251 across all the mutagen doses and their combinations. For shoot length, HPW
251 showed more reduction as compared to HPW 89 at lower dose. It may be attributed to the difference
in shoot length of the parent (control) varieties. In both wheat varieties, root: shoot ratio decreased when
the concentrations of gamma rays, EMS and their combinations increased. In case of EMS and gamma
rays, HPW 251 exhibited more reduction in SVI (seedling vigour index). However, in combination HPW
89 showed the highest reduction in SVI. Under field conditions also more reduction in germination
percentage was observed in HPW 89. HPW 251 have higher survival rates at the heading and maturity
stages. Mutagenic frequency was found to be higher for the combination treatment 0.9% EMS +350Gy.
Highest mutagenic effectiveness of EMS was observed at dose of 0.3% in both the varieties. The results
regarding mutagenic efficiency in general showed a decline when the concentrations of gamma rays,
EMS and their combinations increased. Analysis of variance revealed significant differences among
wheat mutant lines for all the agro-morphological traits except tillers/ plant. High heritability coupled
with high genetic advance was recorded for biological yield/plant, harvest index, peduncle length and
flag leaf length. Days to 75% maturity, spike length, harvest index, grains/spike and 1000-grain weight
showed significant positive correlation with grain yield/plant. Biological yield showed highest direct
effect followed by harvest index. For grain hardness mutant Mt21 was found to be significantly superior
than the best check, while other 10 mutant lines were statistically at par with this best check. Two mutants
(Mt 62 and Mt63) were found to be yellow rust resistant,24 wheat mutants were found resistant to
powdery mildew. One mutant line Mt23 was found to be superior for grain yield and grain hardness.
Based on overall disease screening data Mt45, Mt53 and Mt87 were resistant to both powdery mildew
and yellow rust. Preliminary findings on the differential response of soft and hard wheat lines to the
mutagens and their combination treatments could be further studied by working out mutagenic
effectiveness and efficiency on more parameters of biological damage. High yielding, disease resistant,
hard grained and early flowering mutant progenies may further be subjected to rigorous evaluation by
growing larger populations for isolation of superior mutants in M3.