بررسي القاء ريزش گل تحت شرايط تنش گرما در گياه فلفل (Capsicum annuum L.)

The study of the induction of flower abscission in Capsicum annuum L. under heat stress

To study different plant sensitivity to heat stress, understanding of the factors that inhibit pollination, fertilization and induce flower and fruit abscission and ultimately a cut in yield is necessary. In this study, the possibility of physiological changes during heat stress which cause yield reduction in Capsicum annuum L.cv. malali were investigated. The reduced content of sugars and total proteins of flower and leaf in both control and heat stressed plants were measured and the quality of proteins in both leaf and flower was investigated using electrophoritic technique. The pattern of pollen grain growth on stigma and the growth of pollen tubes in style were investigated using florescent technique. The reduced sugars in those flowers which were formed in heat was significantly lower than th~ control, but no significant differences between reduced sugars in leaf of heat treated and control were observed. Total proteins of both flower and leaf in heat stressed plants were significantly lower than the control. The quality of proteins changed in both leaf and flower of stressed plants when compared with the control based on pattern of protein on electrophoresis.gel. One new band of protein with molecular weight of 23.75 KD was observed in both leaf and flower of heat treated plants. ʹThe observation of anther showed increase in hallow pollen grains. Those pollen grains which germinated on stigma and penetrated into style were unregulated and decreased significantly in those flowers which were under heat stress. More investigation into physiological responses to heat stress and more importantly those which inhibit fruit formation under heat stress are necessary for understanding the effect of heat stress on yield before it can be used in plant breeding and producing heat tolerant plants