灌浆期不同阶段干旱对高粱籽粒淀粉积累的影响

为了研究灌浆期干旱对高粱籽粒淀粉积累的影响,以高淀粉高粱品种铁杂17（TZ17）和低淀粉品种辽杂11（LZ11）为试验材料,在灌浆的早期、中期、后期进行干旱胁迫,通过测定2个高粱品种的总淀粉、直链淀粉、支链淀粉含量及产量指标,研究灌浆期干旱胁迫对高粱籽粒淀粉积累及产量形成的影响。结果表明,2个高粱品种的总淀粉、直链淀粉、支链淀粉含量及产量均受干旱影响呈减少的变化趋势。灌浆期不同阶段干旱胁迫对淀粉积累的影响程度主要表现为灌浆早期>灌浆中期>灌浆后期;高淀粉品种（TZ17）比低淀粉品种（LZ11）更易受到干旱胁迫的影响;干旱胁迫下淀粉指标的变异系数依次为直链淀粉>支链淀粉/直链淀粉>总淀粉>支链淀粉,表明直链淀粉比支链淀粉更易受干旱胁迫的影响;灌浆期干旱胁迫影响籽粒淀粉的积累,降低了千粒重,最终影响高粱的籽粒产量。

Effects of Drought at Different Stages of Grain Filling Period on Starch Accumulation of Sorghum Grains

The objective of this study was to investigate the effects of drought stress during filling period on starch accumulation in sorghum. Two sorghum varieties, Tieza17 (high starch content) and Liaoza11 (low starch content) were planted in pots as the experiment materials. The two varieties were suffered from drought stress at initial stage, middle stage and late stage of grain filling period, respectively. The starch content, amylose content, amylopectin content and grain yield of the two sorghum varieties were investigated. The results showed that the contents of starch, amylose and amylopectin and grain yield were decreased by drought occurred at filling period. The effects of drought stress on starch accumulation at different stages of grain filling period were mainly at the initial filling stage > the middle filling stage > the late filling stage. Tieza17 was more sensitive than Liaoza11 to the drought stress. The variable coefficients of starch indexes under drought stress was as follows: amylose > amylopetin to amylase ratio > total starch > amyloptin, indicating that amylose was more susceptible to drought stress than amylopectin. Generally, drought stress during filling period significantly influenced the starch accumulation, resulting in decrease of the 1000-seed weight, ultimately caused a decline of grain yield in sorghum.