PHOTOSYNTHESIS AND PRODUCTIVITY DURING HIGH-TEMPERATURE STRESS OF WHEAT GENOTYPES FROM MAJOR WORLD REGIONS
PHOTOSYNTHESIS AND PRODUCTIVITY DURING HIGH-TEMPERATURE STRESS OF WHEAT GENOTYPES FROM MAJOR WORLD REGIONS
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DOI：
10.2135/cropsci1990.0011183x003000050034x
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发表时间：
1990-09-01
期刊：
影响因子：
2.3
通讯作者：
PAULSEN, GM
中科院分区：
文献类型：
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作者：
ALKHATIB, K;PAULSEN, GM
小麦（Triticum aestivum L.）的光合速率和类囊体活性受到高温的不利影响，但它们在逆境下决定产量的作用尚不确定。我们的目的是确定在营养和繁殖阶段高温胁迫下单叶光合作用、类囊体活性和生产力之间的关系和基因型变异。来自世界主要小麦产区的10个基因型在中等（22/17）度条件下生长。C白天/晚上)和最高（32/27度）。幼苗期或从花期到成熟期，在摄氏（昼/夜）温度下培养2周。测定净光合作用、叶绿素可变荧光（Fv）和生产力。高温使幼苗和成熟植株的平均光合速率分别降低32%和11%，平均Fv分别降低42%和11%，平均总生物量分别降低32%和15%。与中等温度相比，该处理使籽粒平均重降低20%，籽粒平均产量降低23%。在两个生育期，植物光合速率下降与生产力下降呈极显著相关。光合活性持续时间降低对籽粒相对产量的影响较大，在10个基因型中差异较大。将10个基因型幼苗的类囊体膜加热20 ~ 35℃。C、不耦合电子输运和Fv的测定。类囊体对加热的稳定性变化类似于幼苗对高温的全植物反应，而不是成熟植物。耐高温基因型具有稳定的光合速率和/或长时间的光合活性，高粒重和高收获指数，这些都是潜在的选择标准。
Photosynthetic rates and thylakoid activities are adversely affected by high temperatures in wheat (Triticum aestivum L.), but their role in determining productivity during stress is uncertain. Our objectives were to ascertain relationships and genotypic variability among single-leaf photosynthesis, thylakoid activity, and productivity during high-temperature stress at vegetative and reproductive stages. Ten genotypes from major world wheat-producing regions were grown under moderate (22/17.degree. C day/night) and high (32/27.degree. C day/night) temperatures for 2 wk as seedlings or from anthesis to maturity. Net photosynthesis, chlorophyll variable fluorescence (Fv), and productivity were measured at both stages. High temperature decreased mean photosynthetic rates 32 and 11%, mean Fv 42 and 11%, and mean total biomass 32 and 15% in seedling and maturing plants, respectively. The regime also reduced mean kernel weight 20% and mean grain yield 23% relative to the moderate temperature. Decreased photosynthetic rates and diminished productivity of plants were highly significantly correlated at both growth stages. Relative grain yields were strongly influenced by decreased duration of photosynthetic activity, which ranged widely in the 10 genotypes. Thylakoid membranes from seedlings of the 10 genotypes were heated at 20 to 35.degree. C, and uncoupled electron transport and Fv were determined. Thylakoid stability to heating varied similarly to whole-plant responses to high temperature by seedlings, but not by maturing plants. Genotypes that were most tolerant of high temperature had stable rates and/or long durations of photosynthetic activity, high kernel weights, and high harvest indices, which are potential selection criteria.