东乡野生稻和常规稻“莲香早”苗在干旱胁迫下外观及生理性状变化的比较

An Comparison of the Responses of Dongxiang Wild Rice and a Cultivated Rice Line "Lianxiangzao" to Drought Stress

比较强耐旱的东乡野生稻与常规水稻品种"莲香早"苗干旱处理前后及未经干旱处理的对照组苗的11个形态和生理特性,发现:(1)该两品种干旱前后根含水量的比值变化明显不同,东乡野生稻苗干旱处理后根含水量没有下降,而"莲香早"苗根含水量在干旱处理后比处理前下降近50%,这种变化与它们的抗旱性差异明显相关;(2)干旱后东乡野生稻苗叶片绿色加深,未出现黄叶;"莲香早"苗在干旱后基部叶片变黄,中部叶片也从叶尖开始变黄;(3)干旱处理后东乡野生稻苗叶片展开角度变大,而"莲香早"苗叶片在干旱处理后未见展开角度的变化。上述的东乡野生稻和"莲香早"苗在干旱胁迫下生理和形态特性改变的差异反映了它们耐旱性的不同。

The physiological and morphological changes in the seedlings of Dongxiang Wild Rice and a cultivated rice line ＂Lianxiangzao＂caused by the drought stress were compared.It was found that the following 3 responses to drought stress were quite different between Dongxiang Wild Rice and ＂Lianxiangzao＂：（1）The root water content of ＂Lianxiangzhao＂ seedlings dropped by 50% compared to that of the seedlings before drought treatment,while there was no drop in the root water content of Dongxiang Wild Rice seedlings detected after drought.（2）The leaf color of the Dongxiang Wild Rice seedlings turned darker green,and no yellow leaf was observed after the drought treatment.Different from the leaf color change observed in Dongxiang Wild Rice,the leaves at the base of the ＂Lianxiangzao＂seedlings turned yellow.The tip parts of the leaves at the middle position also turned yellow after the drought treatment.（3）The leaves of the Dongxiang Wild Rice seedlings changed from standing nearly uprightly to stretching horizontally after drought treatment,while no such morphological change was observed in ＂Lianxiangzao＂seedlings after drought.It may be concluded that the difference in the 3 observed physiological and morphological changes between Dongxiang Wild Rice and ＂Lianxiangzao＂seedlings implies the difference between their drought tolerance capability.