水稻幼苗期耐寒生理特性鉴定及利用

【目的】利用水稻耐寒种质资源,培育耐寒性品种。【方法】以5份不同的水稻种质材料为供试品种,幼苗经（5±1）℃低温处理后,进行耐寒性鉴定及相关生理特性测定,筛选耐寒性品种。【结果】索稻1号和南阳占较耐寒,达1级耐寒,桂368和R96-82达2级耐寒,爱叶绿达3级耐寒;叶绿素含量、可溶性糖含量和过氧化氢酶（CAT）活性索稻1号和南阳占表现较高,丙二醛（MDA）含量则较低。【结论】索稻1号和南阳占表现出较强的耐寒性,可作为耐寒育种材料利用。

Identification and utilization of physiological characteristics imparting chilling-resistance in rice at seedling stage

【Objective】The present study was conducted to evaluate the rice germplasm resources in order to identify physiological characteristics imparting chilling resistance at seedling stage. 【Method】Five rice varieties have been treated with low temperature （5±1）℃ and evaluated on the basis of MDA （Malondealdehyde）, soluble sugars, chlorophyll content and the activity of catalase enzyme. 【Result】The rice variety Suodao 1 and Nanyangzhan showed maximum survival percentage compared to other varieties followed by the variety Gui 368 and R96-82. Variety Aiyelü was found least tolerant to chilling stress. The varieties Suodao 1 and Nanyangzhan were found superior to other rice varieties in having higher chlorophy ll content, soluble sugar content and the activity of catalase enzyme, and lesser MDA content. 【Conclusion】The results clearly indicated that varieties Suodao 1 and Nanyangzhan were resistant to chilling stress and may be utilized in breeding programs developed to make cold tolerant varieties.