محمد مدرسی

Considering the importance of impact of heat stress on reproductive organs in wheat and to study the effects of stress on germination percentage of pollen and pollen tube length on 10 wheat cultivars, which include Kaz, Mantna, Gohar, Kuhdasht, Zagros, Alvand, Atrak, Durum, Nyknzhad and Chamran at 25, 30, 35, 40 and 50 degrees Celsius in the form of a factorial experiment based on completely randomized design with three replications was done. Analysis of variance showed a significant difference in the level of one percent (p?0.01) among varieties, temperature and interaction temperature × varieties showed. The highest values of germination percentage at 25°C belonged to Chamran and Kaz 95 and 93 percent respectively. Kaz with 80, 74 and 56 percent pollen germination respectively had heighest presentage of pollen at 30, 35 and 40° C. and the Mantna with 39 and 27 percent pollen germination had lowest levels of pollen tube at 30 and 40 degrees, respectively. Mantna had least amount of pollen tube at all 5 temperature during 292, 214, 184, 151 and 110 microns, respectively. Heat tolerant varieties can be as a criterion for selection of resistant varieties and study to find QTL source used to heat stress tolerance.