등숙기간중 온도와 벼 이삭 지경간 곡립의 형태 형성차이

To clarify the effect of temperature during ripening on grain quality, rice plant which was grown under normal natural conditions untill heading stage was subjected various temperature regimes during grain filling stage. Three varieties, Odaebyeo, Hwaseongbyeo and Dongjinbyeo were used. Grains on primary and secondary-rachis branches were harvested seperately and measured specific gravity, grain size and weight. The optimum daily temperature for grain filling of rice during ripening period was about 22~circC and grain filling under alternating temperature(26/18~circC , day /night) was better than constant temperature (22 /22~circC ) based on 1, 000-grain weight and yield. Grain size based on volume per grain was smallest under the constant temperature of 22 /22~circC . The size of secondary-rachis branches was smaller than primary-rachis branch. The difference in size between primary and secondary-rachis branches was biggest in Hwaseongbyeo, followed by Odaebyeo and Dongjinbyeo. The temperature regimes treated did not influence the grain size difference between branches so much. The 1000-grain weight was lighter under high temperature than low temperature in Odaebyeo, but reversed tendency was observed in Dongjinbyeo of secondary rachis-branches.