关键词: 水稻, 两用核不育系, 亲本繁殖, 播期, 育性转化敏感期, 自交结实率

Abstract:

Seven representative dual-purpose genic male sterile lines of rice were selected as experimental materials, and a sowing date experiment was conducted at the breeding base of rice dual-purpose genic male sterile lines in Shidian County to study the fertility transformation characteristics of different types of dual-purpose genic male sterile lines and the optimal sowing date for high-yielding reproduction of male sterile lines. The results showed that the sowing date had a significant impact on the fertility conversion and self-pollination rate of sterile lines. The peak values of fertility conversion and self-pollination rate of different male sterile lines varied greatly with the change of sowing date, and the tested sterile lines all had the optimal sowing date. The fertility conversion of photosensitive japonica sterile lines was mainly influenced by light length. Under the condition of ensuring safe full heading, delaying sowing was beneficial to fertility transformation and improving self-pollination rate, thus increasing reproductive yield. Due to the short growth period and rapid growth and development, the temperature sensitive early indica male sterile lines could achieve basic yield by early sowing to utilize the short-term low temperature in early June under the premise of ensuring the seedling age. The growth and development and fertility transformation of different temperature sensitive mid indica male sterile lines varied significantly. Identifying the optimal sowing date was the key to their high yield and high efficiency reproduction. By analyzing the temperature changes of the rice dual-purpose nuclear male sterile line breeding base in Shidian County over the years, it was found that the probability of high temperatures occurring from late June to mid July was high. The sensitive period of male sterile line reproduction should avoid this period as much as possible.

Key words: rice, dual-purpose genic male sterile line, parental reproduction, sowing date, sensitive period of fertility transformation, self-pollination rate