Apex Development of Three Wheat Cultivars in the Presence of Salinity

Intra-specific variations in apex development of two salt-tolerant cultivars (Cross Rowshan ۱۱ (CR) and Kharchia-۶۵) and one salt-sensitive cultivar (Ghods) of spring wheat (Triticum aestivum L.) grown in sand culture at selected levels of salinity (۰, ۱۰۰, ۲۰۰, and ۳۰۰ mol m-۳ NaCl and CaCl۲ in ۵:۱ molar ratio) were studied. To determine the apex lengths and the number of spikelet primordia in the apex, the main shoot apex was dissected. Results indicated that final spikelet number of wheat cultivars decreased with increasing salinity. Cultivars showed different responses to a particular level of salinity. Duration of spikelet development from double ridge to terminal spikelet, spikelet number and apex length declined in the presence of salinity. Both shorter duration and reduced rate of spikelet initiation were responsible for reduction in spikelet number in salt-treated plants. Cultivar CR showed a better performance during spikelet initiation period and produced relatively more spikelets under saline conditions than the others.