水稻光温敏核不育系育性敏感期高温对异交特性的影响

以培矮64S、Y58S、广占63–2S、H638S为材料,R527为恢复系,在育性敏感期利用人工气候室以24、27、30、33、36℃5个温度连续处理6 d,以田间自然温度条件作对照(CK,平均温度29.8℃),研究温度对不育系幼穗生理生化特性和抽穗开花期异交特性的影响。结果表明:培矮64S和Y58S在27℃处理时柱头总外露率最高,分别为86.81%、86.06%,广占63–2S和H638S在24℃处理时柱头总外露率最高,分别76.24%、81.76%;4个不育系的柱头活力系数均在24℃处理时表现最好,分别为1.96、2.12、1.74、1.94;培矮64S、广占63–2S和H638S在24℃处理时异交结实率最高,分别为58.87%、54.22%、50.50%,Y58S在27℃处理时异交结实率最高,为58.96%;33℃处理时,4个不育系的过氧化物酶(POD)活性显著高于对照;36℃处理时,4个不育系丙二醛(MDA)和脯氨酸的含量显著高于对照。综合以上结果,培矮64S育性敏感期以24℃处理较好,Y58S、广占63–2S、H638S育性敏感期以27℃处理较好。

Effect of high temperature on outcrossing characteristics at the fertile sensitive stage of photo thermo sensitive genic male sterile (PTGMS) rice lines

Four sterile lines (Peiai64S, Y58S, Guangzhan63-2S and H638S) and the restorer line R527 were used as materials. Five temperature gradients(24, 27, 30, 33 and 36℃ in artificial climate chamber) and the natural temperature (as control)were treated to the four sterile lines for 6 days at the fertile sensitive stage of heading to flowering stage respectively, to study the effect of temperature on physiological biochemical characteristics of young spike and outcrossing characteristics. The results showed that the stigma exposure rates of Peiai64S and Y58S were highest at 27℃, which were 86.81% and 86.06% respectively, while the stigma exposure rates of Guangzhan63-2S and H638S were highest at 24℃, they were 76.24% and 81.76%; the stigma vitalities of Peiai64S, Y58S, Guangzhan63-2S, and H638S were best at 24℃, which were 1.96, 2.12, 1.74 and 1.94, respectively; the outcrossing rates of Peiai64S, Guangzhan63-2S and H638S were highest at 24℃, which were 58.87%, 54.22% and 50.50% respectively, while the outcrossing rate of Y58S was highest at 27℃, which was 58.96%; the content of peroxidase (POD) of four sterile lines increased significantly at 33℃ compared with the control, while the content of malondialdehyde (MDA) and proline increased significantly at 36℃ compared with the control. There were differences in temperature sensitivity between the male sterile lines, 24℃ treatment during the sensitive period was the best for Peiai64S fertility-sensitive period, while 27℃ was the best temperature for Y58S, Gangzhan63-2S, H638S.