Preliminary study on seed setting rate for high temperature response of hybrid rice.

Under heat stress with variational temperature in heading and flowering stage,the response of seed setting rate of hybrid rice was studied by psychrometric cells.The results indicated that the sensitive stage to high temperature of seed set of hybrid rice was flowering stage.The varieties responses of seed setting rate were different at high temperature.When daily mean temperature 35 ℃ during flowering stage,Ⅱyou 7 and D you 527 could keep higher seed setting rate;when daily mean temperature≥30 ℃ during flowering stage,the seed setting rate of Ⅱyou 802 decreased rapidly.