土壤干旱胁迫对不同水稻品种叶片卷曲的影响

Influence of Soil Drought Stress on Leaf Rolling Index in Different Rice Varieties

在人工控制土壤水分条件下 ,以 13个具有不同耐旱性的栽培稻品种 (组合 )为供试材料 ,研究了在分蘖盛期土壤断水后随着干旱胁迫的加重叶片卷曲度 (LRI)的动态变化及其与蒸腾、光合特性和叶片水分利用的关系。结果表明 ,不同品种的LRI明显增大的起始日期、明显增大期日均增量和最大值存在着显著差异 ,并依据叶片卷曲表现可将参试品种划分为敏感型 (如中旱 1号 )、中间型 (如旱稻 8号 )和钝感型 (如巴西陆稻 )三种类型。随着土壤断水后干旱胁迫的加重 ,LRI逐渐增大。LRI与气孔导度 (SC)、蒸腾速率 (TR)和净光合速率 (Pn)的关系因品种类型而异 ;LRI每增加 1级 ,中旱 1号、旱稻 8号和巴西陆稻的SC分别降低 0 .2 6、0 .2 0和 0 .17mm/s,TR分别降低 0 .86、0 .66和 0 .49mmol/ (m2 ·s) ;Pn呈显著下降的叶片卷曲度中旱 1号明显小于巴西陆稻。当叶片适度卷曲时 ,WUE随LRI值的增大而提高 ,中旱 1号LRI的变化同时引起TR和Pn显著改变进而影响WUE ,而旱稻

The influence of soil drought stress on leaf rolling index (LRI) and its relatio nship with stomatal conductance (SC), transpiration rate (TR), net photosyntheti c rate (Pn) and water use efficiency (WUE) were investigated by using 13 rice ( Oryza sativa L.) varieties differing in drought resistance under the condit ion of artificially-controlled soil water. The drought stress in soil was initi ated at effective active tillering stage and ended at booting stage by re-irrig ating. Results showed that there were obvious differences among rice varieties in the initial increasing date, increasing rate and maximum value of LRI. T hirteen rice varieties may be classified into three categories, i.e. sensitive ( e.g. Zhonghan 1), intermediate (e.g. Handao 8) and insensitive (e.g. I APAR 9 ), according to the development of LRI in response to soil drought stress. The LRI increased with the soil water stress for all varieties, but there was drama tic difference among varieties in the relationships between LRI and SC, TR, Pn a nd WUE. With the increase of every one scale in LRI, SC in Zhonghan 1, Handao 8 and IAPAR 9 decreased by 0.26, 0.20 and 0.17 mm/s, respectively, and TR decrease d by 0.86, 0.66 and 0 49 mmol/(m 2 ·s), respectively. The LRI resulting in substantial reduction in Pn was much smaller in Zhonghan 1 than that in IAPAR 9 . It also showed that the moderate LRI increased WUE, and the effect of LRI on WUE could be attributed to the change of both Pn and TR for Zhonghan 1, but for IAPAR, only the change of TR was significantly related.