KERNEL NUMBER PER SPIKE IN WHEAT (TRITICUM-AESTIVUM L) - RESPONSES TO PREANTHESIS SHADING
KERNEL NUMBER PER SPIKE IN WHEAT (TRITICUM-AESTIVUM L) - RESPONSES TO PREANTHESIS SHADING
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DOI：
10.1071/pp9800169
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发表时间：
1980-01-01
期刊：
影响因子：
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通讯作者：
STOCKMAN, YM
中科院分区：
文献类型：
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作者：
FISCHER, RA;STOCKMAN, YM
在盆栽条件下，对几个小麦品种进行了8-11天的单次遮光处理，遮光时间为开花前36天至开花。其目的是确认敏感性的内核数，以减少在现场观察到的辐照度，并调查其原因。花前10-13 d遮光对穗粒数的影响最大，主要是通过对小穗粒数的影响来实现的。这与开花期穗干重的最大减少和每单位穗干重的主管小花（花药发育完全的小花）数量的减少有关;小花生育力（每主管小花的粒数）不受影响。在对遮荫最敏感的阶段，植株总干重增量的约30%被分配给穗，但遮荫并没有改变这种分配。水溶性碳水化合物（WSC）含量的最大穗（30-40%，在干基在无阴影的植物）出现在开花前15天。在最敏感时期遮光可暂时降低穗部WSC浓度，减少中央小穗小花心皮中的淀粉含量，并通过增加远端小花的退化而降低小花存活率。在此期间之前或之后遮光减少籽粒数较少，减少穗干重，但不减少单位穗干重的成花数。同化物供应的减少可能是穗中这些反应的原因。
Several cultivars of wheat, grown in pots in a controlled environment, were subject to single shading periods of 8-11 days within the interval from 36 days before anthesis until anthesis. The aim was to confirm sensitivity of kernel number to reduce irradiance as observed in the field and to investigate its causes. Shading periods centered 10-13 days before anthesis had biggest effects on kernel number per spike through effects on kernels per spikelet. This was associated with greatest reductions in the spike dry weight at anthesis and with reductions in the number of competent florets (florets with full anther development) per unit spike dry weight; floret fertility (kernels per competent floret) was unaffected. Approximately, 30% of the total dry weight increment of the plant was being allocated to the spike at the stage of greatest sensitivity to shading, but shading did not alter this partitioning. Maximum water soluble carbohydrate (WSC) content of the spike (30-40% on a dry basis in unshaded plants) occurred at 15 days before anthesis. Shading at the most sensitive period reduced temporarily WSC concentration in the spike, reduced stainable starch in carpels of florets of central spikelets, and reduced floret survival by increasing degeneration of distal florets. Shading before or after this period reduced kernel number less, reducing spike dry weight but not competent florets per unit spike dry weight. Reduced assimilate supply is probably the cause of these responses in the spike.