TITLE:
Estimation of Variability, Heritability and Genetic Advance for Phenological, Physiological and Yield Contributing Attributes in Wheat Genotypes under Heat Stress Condition
AUTHORS:
Md. Mukhtar Hossain, Md. Abul Kalam Azad, Md. Shamiul Alam, Touria El-Jaoual Eaton
KEYWORDS:
Wheat Genotype, Variability, Heritability, Genetic Advance, PCV (Phenotypic Co-Efficient of Variation), GCV (Genotypic Co-Efficient of Variation), Heat Tolerance
JOURNAL NAME:
American Journal of Plant Sciences,
Vol.12 No.4,
April
21,
2021
ABSTRACT: The investigation was carried out in focusing the
genetic variability for different traits of wheat influenced by heat tolerance
mechanism to find out relationships among phenological, physiological and yield
contributing traits. Spring wheat cultivar of 25 genotypes were selected and
cultivated under late sowing condition at the Regional Wheat Research
Institute, Shympur, Rajshahi, Bangladesh from December, 2016 to April, 2017.
Significant variability among the genotypes exposed for different traits
related to heat tolerance. Results showed that the genotypes G24, G10, G01,
G13, G16, G25 and G14 ranked as better
category considering maximum number of traits in mean performance
indicating their tolerance to heat stress under late sowing condition.
Phenotypic variances (σg2) of all traits
were greater than those of genotypic variances (σg2). The same
trends were also found in their co-efficient of variances. The phenotypic
co-efficient of variances (PCV) of all traits were greater compare to those of
genotypic co-efficient of variances (GCV) and their values were closer to each
other. The heading days (HD), canopy temperature at vegetative stage (CTvg),
canopy temperature at grain filling stage (CTgf),
biomass, plant height (PH), spike/m2 (SPM), spikelet/spike (SPS), grain/ spike (GPS), thousand grain
weight (TGW) and yield exhibited higher heritability (hb2)
estimated under irrigated late sowing (ILS) condition. Under the same ILS
condition SPAD, SPM, SPS, GPS, TGW and yield showed moderate to high genetic
advance (GA) obtained through computing their mean percentage (%) and the rest
traits HD, maturity days (MD), CTvg, CTgf, biomass, PH
and harvest index (HI) exposed smaller genetic advance (% mean). The
co-efficient of variation (CV%) of all attributes in all genotypes were
significantly lower (1.36 - 6.96).
Both heritability and genetic advance were found lower for MD, SPAD and HI
indicated their non additive genetic effects for which these traits might not be recommended for selection. However, spike/m2, spikelet/spike, grain/spike, thousand grain
weight and yield belonged to higher heritability and high to moderate
genetic advance in mean percentage (%) along with wide genetic variation and
lower environmental influence in heat stress situation indicated the most
likely heritability due to the effects of additive genes that might be
suggested as effective process of selection for these traits in heat stress
condition.