Genetic Variation in Wheat (Triticum aestivum L.) Seedlings for Nutrient Uptake at Different Salinity and Temperature Regimes

Abstract

In the present study, 20 genetically diverse genotypes of wheat were evaluated for salt (0.0% and 0.3%; EC 2.8 and 11.4 mS/cm, respectively) and heat stress (15°C and 25°C) tolerance. The petridishes were irrigated with 5 ml of test solution after draining the previous day's solution for the fi rst 5 days which were later increased to 10 ml. On the 11th day, the experiment was terminated and the observations were recorded on germination percentage, fresh weight of shoot/seedling (mg), fresh weight of root/seedling (mg), dry weight of shoot/seedling (mg), dry weight of root/seedling (mg). The data for Na⁺, K⁺, Ca²⁺, Na⁺/K⁺ ratio, Na⁺/Ca²⁺ ratio, Cu²⁺, Zn²⁺, Mn²⁺ contents in roots and shoots were also recorded. Salt and high temperature stress reduced the growth of all genotypes of wheat. However, cultivars differed signifi cantly to both salt and temperature stress. Mukta, Raj-3765, Sonalika, Kharchia-65 were found to be best suited to salinity, while PBW-226 and Raj-2535 were very sensitive to salinity and higher temperature. Accumulation of Cu²⁺, Zn²⁺ and Mn²⁺ was positively correlated with all other attributes. However, Na⁺ was negatively correlated with K⁺ and Ca²⁺. Therefore, in order to breed effi cient genotypes which can withstand the effects of salinity the positive association between Na⁺ and other contents will have to be broken. This can be done by biparental mating design or recurrent selections.