溫度對高粱花粉活力與授粉的影響

Abstract

為探討低溫逆境對高粱生殖生理的影響，本研究調查不同溫度對花粉活力以及開花行為的表現，花粉活力係以碘染劑（I2/KI）、FDA(fluorescein diacetate）螢光染劑、TTC或體外（in vitro）發芽率作為評估指標。不同溫度對花粉活性的試驗結果顯示，正常的花粉在不同溫度下的發芽率有顯著差異，其中35℃下花粉的發芽率約為15℃的二倍，同時不同品種的花粉親其體外發芽率亦有顯著的差別。此外參試的所有品系穎花在日溫20℃以上皆可正常開花，唯在15℃以下皆不開花。由於小穗花無法正常開花，因此花粉粒雖具有正常的活性，但無法完成正常授粉，因此影響種子收量。 The objective of this study was designed to investigate the effect of low temperature on reproductive physiology of sorghum plant. The viability of pollens and flowering response to low temperature were evaluated. Pollen viability was determined using the iodine, fluorescein diacetate and tetrazolium chloride staining technique and in vitro germination test. The results indicated that significant differences existed among temperature treatments for pollen viability. The germination percentage of pollen at 35℃ was 2 times higher than that of 15℃. Cultivar differences also existed for in vitro germination. On the other hand, all the cultivars were capable of flowering at or above 20℃. Low temperature of 15℃ was inhihitory to flowering. The poor seed setting of sorghum might be linked to the incapability of flowering for spikelets although pollen were viable under low temperature.