两系杂交稻制种的气候适应性研究

研究两系杂交稻的首要不育系———培矮64S制种的气候适应性, 一方面可为两系杂交稻的生产提供决策参考, 另一方面也可为其它不育系的研究提供借鉴。分析气候适应性时, 首先利用播种—抽穗天数及其对应的气象资料, 建立发育期模型; 然后利用自交结实率资料及其对应的气象资料建立育性量化模型, 并求出育性转换的光温指标; 最后将我国稻区35个站点42年 (1951~1992年) 的气象资料代入发育期模型, 求出各站点的可能出穗持续期 (最早出穗期—最晚出穗期的历期), 对比育性转换的光温指标, 确定培矮64S在80%、90%和95%保证率下连续不育 (可育) 的初、终日, 将连续不育期作为生产杂交稻种子的季节, 将连续可育期作为繁殖培矮64S的季节。结果显示:培矮64S仅能在海南岛及云贵高原中低海拔地区自交繁殖; 而在东北、云贵高原以外的稻区, 培矮64S均可用于生产两系杂交稻的种子, 各稻区制种季节的长短、起止日期与种植地的纬度、海拔高度相关。

Study of Climatic Adaptability of Two-line Hybrid Rice Seed Production

The research on the climatic adaptability of the predominant sterile line, Peiai 64S, can provide references for decision making in the production of two line hybrid rice and the study of other sterile lines. The growth model is constructed by using the number of days from seeding date to heading date and the corresponding meteorological data. The fertility model is developed based on the seed setting rate along with the corresponding meteorological data, and the switch indices of critical sterility induced by temperature and day length are calculated. The 42 year meteorological data of 35 weather stations in China are input into the growth model and the potential duration for the heading period (the duration from the earliest heading date to the latest heading date) is deduced for each station. According to the switch indices of critical sterility induced by temperature and day length, the beginning and ending dates of the sterile and fertile duration under the guarantee rates of 80%, 90% and 95 % are given. During the sterile duration Peiai 64S can be used for producing hybrid seeds; and during the fertile duration, it can be used for multiplying itself. The results show that Peiai 64S can multiply only in Hainan Island or in the lower altitude area of the Yungui Plateau, whereas it can produce hybrid seeds in any rice production regions except Northeast China and the Yungui Plateau. The seasons for producing hybrid rice seeds are related to the altitude and latitude of the rice planting areas.