Heritability estimates for winter hardiness in lentil under natural and controlled conditions

Heritability analysis for cold tolerance in lentil was conducted using parental, F-2 and F-3 populations at two locations in Balochistan, Pakistan and one controlled environment in Fort Collins, Colorado, USA. Populations of parental and F-2 families were grown over 2 years (1991-92 and 1992-93) at Quetta, Balochistan, Pakistan. In 1992-93, parental and F-2 families were studied at Quetta, and Kalat, Balochistan, Pakistan. Evaluation for normality using non-transformed and log-transformed data failed. Attempts to use analysis of variance were then abandoned in favour of parent-offspring regression for narrow-sense heritability. Estimates of narrow-sense heritability ranged from 0.32 +/- 0.06 to 0.71 +/- 0.16 under field conditions. Under controlled conditions, the estimated heritability was maximized at 1.00 +/- 0.17 using 6- to 8-week-old lentils. Significant transgressive segregants were found in five of the six populations in the F-3 generation. Transgressive segregants appeared in the controlled F-3 generation but were not observed in held environments. This indicates that cold tolerance is under additive gene control and is environmentally sensitive in gene expression.