The use of seedling leaf death score for evaluation of drought resistance of rice
The use of seedling leaf death score for evaluation of drought resistance of rice
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DOI：
10.1016/s0378-4290(97)00074-9
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发表时间：
1998-01-01
影响因子：
5.8
通讯作者：
Fukai, S
中科院分区：
文献类型：
--
作者：
Mitchell, JH;Siamhan, D;Fukai, S
幼苗叶片死亡（干旱评分）作为水稻抗旱性的选择指标已被广泛应用于水稻育种中。研究了水稻营养生长期水分胁迫下影响水稻品种干旱评分的因素及其与产量的关系。分别由21个和8个品种组成的两个高地试验在营养生长期间进行水分亏缺。在第一个实验中，植物生长在三种胁迫条件下，黎明前叶水势，表皮导度，冠层光截获和干旱评分在胁迫期间进行了测定。在第二个试验中，还研究了叶面积、水分利用、干物质生长和籽粒产量。在两个实验中，植株大小存在较大的基因型变异，这影响了水分胁迫和干旱评分的发展。植株较大的品种干旱评分较高。干旱评分与光截获量呈显著正相关（r = 0.74* *，n = 63）。然而，协方差分析表明，干旱评分的基因型变异存在后，考虑到植株大小的影响。叶片水势存在显著的基因型差异，与干旱评分呈显著负相关（r = 0.75* *，n = 42）。叶面积大的品种在胁迫期间倾向于损失更多的绿色叶，但这并不导致胁迫期间或之后的干物质生长减少。干旱胁迫后的绿色叶面积和枯叶量（干旱评分）决定着随后的干物质生长（r = 0.45* *，n = 32），幼苗干旱评分与籽粒产量无相关性。因此，在抗旱性的营养筛选程序中，干旱评分的估计值应该伴随着植物大小的估计值。(C)1998年Elsevier Science B.V.
Leaf death (drought score) of seedlings has been extensively used in rice breeding programs as a selection index for drought resistance. This paper investigates the factors that affect the drought score of rice cultivars exposed to water stress during the vegetative stage and the relationship between drought score and yield. Two upland experiments consisting of 21 and 8 cultivars, respectively, were subjected to water deficit during vegetative growth. In the first experiment, the plants were grown under three stress conditions and pre-dawn leaf water potential, epidermal conductance, canopy light interception and drought score were determined during the stress period. In the second experiment leaf area, water use, dry matter growth and grain yield were also examined. Large genotypic variation in plant size existed in both experiments and this affected development of water stress and drought score. The cultivars with large plant size tended to have high drought score. A significant positive correlation (r = 0.74* *, n = 63) existed between drought score and Light interception. However, analysis of covariance indicated that genotypic variation in drought score existed after the effect of plant size was taken into account. Significant genotypic variation in leaf water potential existed and this was negatively correlated with drought score (r = 0.75* *, n = 42). Cultivars with large leaf area tended to lose more green leaves during the stress period, but this did not result in reduced dry matter growth during or after the stress period. Green leaf area remaining after the stress period, and not amount of dead leaf (drought score) determined subsequent dry matter growth (r = 0.45* *, n = 32), and there was no correlation between drought score of seedlings and grain yield. Thus for use in a vegetative screening program for drought resistance, estimates of drought score should be accompanied by estimates of plant size. (C) 1998 Elsevier Science B.V.