华南双季超级稻始穗期低温胁迫及耐冷性评价

On chilling tolerance of South-China double cropping super rice varieties(combinations) with chilling stress at initial heading stage

2007年晚季以玉香油占、天优122、天优10号、五丰优128、特优138等5个最新育成的华南双季超级稻品种(组合)为供试材料,在广州进行了始穗期低温胁迫试验.结果表明:1)始穗期16℃低温处理5 d,各供试材料的主茎单穗产量均有较大幅度的降低,降幅因品种(组合)不同而异,且随着处理时间的延长,杂交稻主茎单穗产量的降幅明显增大;2)22,18℃低温下不论是处理5 d还是7 d,对特优138的主茎单穗产量均没有消极影响,但导致了玉香油占、天优122、天优10号和五丰优128不同程度减产;3)始穗期低温主要通过影响主茎结实率降低主茎产量,对主茎穗长、每穗总粒数和单粒粒重无明显影响;4)特优138耐低温胁迫能力最强,玉香油占次之,天优10号、天优122、五丰优128较差.

Five new-bred South-China double cropping super rice varieties （combinations） Yuxiangyouzhan, Tianyou 122, Tianyoul0 hao, Wufengyou128 and Teyou138, were chosen to study the chilling tolerance at initial heading stage in Guangzhou in the late season, 2007. The results showed that 1） The main spike yield of all the varieties （combinations） deeply dropped differently under the chilling stress of 16 ℃ treated 5 d at initial heading stage, and more, the main spike yield of the hybrid rice droped more with the treating time longer. 2） Either treated 5 d or 7 d, the chilling stress of 18℃ and 22℃ did not cause the main spike yield of Teyou138 to drop. But the main spike yield of Yuxiangyouzhan, Tianyou 122, Tianyou 10 hao and Wufengyou128 dropped differently under the chilling stress of 18℃ and 22℃. 3） Chilling stress at initial heading stage caused the yield of main spike to decline through declining its seed-setting rate. Chilling stress at initial heading stage had no effects on both the length and the total pellets of the main spike, and also it had no effects on the single pellet weight of the main spike. 4） In this experiment, the chilling tolerance of Teyou 138 was the highest among the varieties and combinations, Yuxiangyouzhan was the second high, and Tianyou 10 hao, Tianyou 122 and Wufengyou 128 were low.