More fertile florets and grains per spike can be achieved at higher temperature in wheat lines with high spike biomass and sugar content at booting
More fertile florets and grains per spike can be achieved at higher temperature in wheat lines with high spike biomass and sugar content at booting
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DOI：
10.1071/fp13232
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发表时间：
2014-01-01
影响因子：
3
通讯作者：
Miralles, Daniel J.
中科院分区：
文献类型：
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作者：
Dreccer, M. Fernanda;Wockner, Kimberley B.;Miralles, Daniel J.
为了更好地利用遗传变异，需要了解在较高温度下调节小麦小花和粒数的过程。在这项研究中，我们验证了这样的假设，即在较高的温度下，小花育性的降低与可溶性糖的减少有关，并且这种反应在低水溶性碳水化合物(WSC)的基因型中加剧。4个对照茎秆WSC的重组自交系在20/10℃和11h光周期下生长到顶端小穗，然后以20/10℃或28/14℃与11h或16h光周期的析因组合继续生长，直到开花。在不同环境中，高WSC品系每穗粒数较多，每穗小花数较多。可育小花的数量与孕穗期的穗生物量相关，进而与葡萄糖含量相关，两者在高WSC系中都较高。在孕穗期，高WSC品系比低WSC品系具有更高的固定C-13和更高的光合作用和蔗糖运输相关基因的表达水平，以及更低的蔗糖降解水平。在较高温度下，高WSC品系孕穗前小花发育的本征速率较慢。籽粒结实率随着孕穗前小花发育的内禀速率而下降，在28/14℃和16h条件下，WSC高的品系具有优势。
An understanding of processes regulating wheat floret and grain number at higher temperatures is required to better exploit genetic variation. In this study we tested the hypothesis that at higher temperatures, a reduction in floret fertility is associated with a decrease in soluble sugars and this response is exacerbated in genotypes low in water soluble carbohydrates (WSC). Four recombinant inbred lines contrasting for stem WSC were grown at 20/10 degrees C and 11 h photoperiod until terminal spikelet, and then continued in a factorial combination of 20/10 degrees C or 28/14 degrees C with 11 h or 16 h photoperiod until anthesis. Across environments, High WSC lines had more grains per spike associated with more florets per spike. The number of fertile florets was associated with spike biomass at booting and, by extension, with glucose amount, both higher in High WSC lines. At booting, High WSC lines had higher fixed C-13 and higher levels of expression of genes involved in photosynthesis and sucrose transport and lower in sucrose degradation compared with Low WSC lines. At higher temperature, the intrinsic rate of floret development rate before booting was slower in High WSC lines. Grain set declined with the intrinsic rate of floret development before booting, with an advantage for High WSC lines at 28/14 degrees C and 16 h. Genotypic and environmental action on floret fertility and grain set was summarised in a model.