拔节期低温对小麦穗花发育与籽粒淀粉粒分布的影响

Effect of Low Temperature at Jointing Stage on Spikelet and Floret Development and Starch Granule Size Distribution of Wheat

为明确拔节期低温胁迫对小麦穗花发育与籽粒淀粉粒分布的影响,以‘宁麦13’、‘华成3366’等8个小麦品种为材料,设置拔节期夜间低温处理,研究低温对小麦籽粒产量、穗花发育与胚乳淀粉粒分布特征的影响。结果表明,拔节期低温显著降低小麦籽粒产量,低温处理产量较对照降低46.55%~66.09%。低温处理穗数、穗粒数与籽粒质量分别较对照降低2%~31%、17%~55%与4%~26%。可见,拔节期低温对小麦穗粒数影响最大,籽粒质量次之,穗数最小。拔节期低温显著降低小麦的总小穗数,主要是由顶部败育小穗数与基部败育小穗数增加造成。低温显著降低小麦总小花数、结实小花数,其中对基部结实小花数和弱势结实小花数影响更大。低温胁迫显著降低籽粒B型淀粉粒体积、表面积百分比,其中与<2.8μm淀粉粒组相比,低温对2.8~10μm淀粉粒组体积、表面积百分比的降幅更大。拔节期低温对B、A型淀粉粒数目百分比无显著影响。可见,本试验中小麦拔节期低温不利于籽粒B型淀粉粒的生长,即其个体体积的增大。

In order to determine the effect of low temperature stress at jointing stage on spikelet and floret development and starch granule size distribution of wheat,eight wheat varieties were used to study the effect of low temperature on grain yield,spikelet development and starch granule size distribution.The results showed that low temperature caused a obvious drop in grain yield of wheat.The grain yield under low temperature treatment decreased by 46.55%-66.09%compared with the control.The number of spike per hectare,kernels per spike and grain mass of low temperature treatment decreased by 2%-31%,17%-55%and 4%-26%compared with the control.It is suggested that low temperature at the jointing stage had a significant effect on grain number per spike,followed by grain mass and number of ears.Low temperature at jointing stage significantly decreased the total number of spikelets,which was mainly caused by the increase of the number of top and base abortive spikelets.The low temperature significantly reduced the total number of florets and the number of fertile florets,especially the number of basal fertile florets and weak fertile florets.Compared with<2.8μm starch granules,the volume and surface area percentage of the 2.8-10μm starch granules decreased greatlyunder low temperature treatment.Low temperature had no significant effect on the number percentage of B and A type starch granules.The results suggested that low temperature was unfavourable to the growth of B type starch granules.