种子引发对杂交水稻幼苗耐盐性的生理效应

Physiological Effects of Seed Priming on Salt-tolerance of Seedlings in Hybrid Rice (Oryza sativa L.)

用 4种引发剂溶液处理 2个杂交稻品种汕优 10和两优培九种子 ,并测定种子和幼苗脯氨酸、可溶性总糖、果糖和蔗糖含量。结果表明 ,引发处理种子脯氨酸和蔗糖含量提高 ,而可溶性糖和果糖含量降低。引发降低了盐胁迫后汕优 10幼苗脯氨酸含量 ,但提高了两优培九幼苗脯氨酸含量。引发处理还能提高盐胁迫后幼苗的可溶性总糖、果糖和蔗糖含量及水稻幼苗耐盐指数和耐盐比率。杂交水稻幼苗耐盐指数、耐盐比率与种子脯氨酸含量 ,以及盐胁迫后幼苗内部可溶性总糖、果糖和蔗糖含量均呈显著正相关 ,而与种子果糖含量呈显著负相关。盐胁迫后幼苗的可溶性总糖、果糖含量与种子可溶性总糖和果糖含量均呈显著负相关 ,而种子脯氨酸含量与盐胁迫后幼苗果糖含量呈显著正相关。因此 ,种子引发通过降低种子果糖水平 ,增加种子脯氨酸含量和盐胁迫幼苗果糖水平 ,从而增强杂交水稻幼苗的耐盐性。试验还表明 ,杂交水稻组合汕优 10耐盐性强于两优培九 ,但引发的效果以两优培九组合更好。

Seeds of two hybrid rice combinations, Shanyou10 and Liangyoupeijiu, were treated with four priming solutions, H 2O, 10 mmol·L -1 proline, 150 mmol·L -1 NaCl and 150 mmol·L -1 NaCl+10 mmol·L -1 proline, for 36 h at 25℃. Nonprimed or primed seeds were germinated in four solutions, 0, 50, 100 or 150 mmol·L -1 NaCl solutions, for 10 d at 30℃. The content of compatible solutes, proline, total soluble sugars, fructose and sucrose in seeds or stressed seedlings was determined. The results showed that significant higher levels of proline and sucrose and lower levels of total soluble sugars and fructose in primed seeds were observed as compared with control (nonprimed seeds). Priming decreased the content of proline in stressed shanyou10 seedling, but improved the content of proline in stressed Liangyoupeijiu seedlings. Priming increased the content of total soluble sugars, fructose and sucrose in stressed seedlings and the tolerance index and tolerance ratio of hybrid rice seedlings. Significant positive correlations between tolerance index and tolerance ratio of seedlings in hybrid rice and content of proline in primed seeds and content of fructose and sucrose in stressed seedlings were observed. Significant negative correlations between tolerance index and tolerance ratio of seedlings and content of proline in primed seeds were found. The content of total soluble sugars in stressed seedlings was only positively correlated with tolerance ratio of seedlings. Significant negative correlations between content of fructose in primed seeds and content of total soluble sugars and fructose in stressed seedlings were also found. Therefore, priming resulted in decreased content of fructose in seeds, and then increased content of proline in seeds and content of fructose in stressed seedlings, thus improved salt tolerance of seedlings in hybrid rice. It also indicated that Shanyou10 had greater salt tolerance than Liangyoupeijiu, but better priming effects were observed in Liangyoupeijiu.