Heat stress effects around flowering on kernel set of temperate and tropical maize hybrids
Heat stress effects around flowering on kernel set of temperate and tropical maize hybrids
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DOI：
10.1016/j.fcr.2011.04.015
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发表时间：
2011-08-14
影响因子：
5.8
通讯作者：
Otegui, M. E.
中科院分区：
文献类型：
--
作者：
Rattalino Edreira, J. I.;Budakli Carpici, E.;Otegui, M. E.
温带玉米（莱亚mays L）杂种最上部穗中的最终粒数小于由该穗中分化的小花数代表的潜力，并且小于从其暴露的花丝数（即，内核集< 1）。当胁迫条件在吐丝前（GS（1））或吐丝期间（GS（2））影响植物生长时，这种趋势会增加，但对于热胁迫效应和热带背景的杂交种，变化的幅度还没有记录。在这项工作中，我们在田间试验（实验（1）和实验（2））中评估了上述性状，包括（i）两种温度制度，控制和白天加热（约20 ℃）。33-40摄氏度在穗水平），（ii）两个15天的时期，在GS（1）和GS（2），和（iii）三个杂种（Te：温带; Tr：热带; TeTr：Te x Tr）。我们还测量了作物开花和吐丝动态，个别植物的丝绸曝光，和开花吐丝间隔（ASI）。三个来源的籽粒损失被确定为：减少小花分化，授粉失败，和籽粒败育。加热影响所有调查性状，但对开花动态的负面影响（i）对开花的影响大于对吐丝的影响，同时ASI下降，（ii）对GS（1）的负面影响大于GS（2）。热还导致以下数量的减少：（i）仅当在GS期间进行时的小花（在Exp中为-15.5%，并且在Exp（2）中为-9.1%），并且仅在Te和TeTr杂种中，（ii）所有GS X杂种组合的暴露的花丝，以及（iii）可收获的籽粒（GS（1）中为-51.8%的平均值，并且GS（2）中为-74.5%的平均值）。籽粒败育可解释最终籽粒数变异的95%（P < 0.001），负热效应对这一损失的影响（38.6%）大于其他损失（
Final kernel number in the uppermost ear of temperate maize (lea mays L) hybrids is smaller than the potential represented by the number of florets differentiated in this ear, and than the number of silks exposed from it (i.e., kernel set < 1). This trend increases when stressful conditions affect plant growth immediately before (GS(1)) or during (GS(2))silking, but the magnitude of change has not been documented for heat stress effects and hybrids of tropical background. In this work we evaluated mentioned traits in field experiments (Exp(1) and Exp(2)), including (i) two temperature regimes, control and heated during daytime hours (ca. 33-40 degrees C at ear level), (ii) two 15-d periods during GS(1) and GS(2), and (iii) three hybrids (Te: temperate; Tr: tropical; TeTr: Te x Tr). We also measured crop anthesis and silking dynamics, silk exposure of individual plants, and the anthesis-silking interval (ASI). Three sources of kernel loss were identified: decreased floret differentiation, pollination failure, and kernel abortion. Heating affected all surveyed traits, but negative effects on flowering dynamics were larger (i) for anthesis than for silking with the concomitant decrease in ASI, and (ii) for GS(1) than for GS(2). Heat also caused a decrease in the number of (i) florets only when performed during GS, (-15.5% in Exp, and -9.1% in Exp(2)), and only among Te and TeTr hybrids, (ii) exposed silks of all GS x Hybrid combinations, and (iii) harvestable kernels (mean of -51.8% in GS(1) and -74.5% in GS(2)). Kernel abortion explained 95% of the variation in final kernel numbers (P < 0.001), and negative heat effects were larger on this loss (38.6%) than on other losses (