EFFECT OF HEAT AND MOISTURE STRESS TREATMENTS ON SEEDLING GROWTH OF WHEAT (TRITICUM AESTIVUM L.) VARIETIES

A pot experiment was conducted in sand culture to evaluate the effect of heat and
moisture stress treatments on seedling growth parameters of eight wheat varieties
sown on two dates under laboratory condition in 2003. Seeds obtained from normal
sowing recorded significantly higher shoot length and root and shoot dry weights
than those from late sown crop. Unfavorable conditions (moisture/heat) for growth
of the seedlings under moisture/ temperature stress adversely affected seedling growth.
Among varieties, UP 2425 and Raj 3765 consistently showed higher seedling vigour
values compared to other varieties which may be attributed to their large seed size.
Variety WH 542 with lowest grain size produced lowest shoot and root dry weight.
Therefore, it appears that seedling vigor parameters are related to seed size which
was evident from significantly positive correlation between 1000 grain weight and
shoot length, shoot dry weight and root dry weight. The values for acquired moisture
stress tolerance were higher than acquired heat stress tolerance. The result of acquired
stress tolerance of seedlings showed that varieties UP 2425, Raj 3765 and PBW 373
had better tolerance to stress situation as compared to other varieties. Acquired
stress tolerance for heat stress (r = 0.87) and moisture stress (r = 0.80) showed
positive correlation with 1000 grain weight