赤霉素与2,4-表油菜素内酯对苦荞灌浆及产量形成的影响

Effects of Gibberellin and 2,4-epbrassinolide on Grain-filling and Yield of Tartary Buckwheat

【目的】明确赤霉素(GA_(3))与2,4-表油菜素内酯(EBR)对苦荞灌浆及产量形成的影响。【方法】设置GA3和EBR不同配比6个处理,研究其对苦荞强弱籽粒之间灌浆特性和淀粉合成酶活性之间的差异,灌浆阶段叶片中抗氧化酶活性和光合特性的变化,以及对农艺性状及产量的影响。【结果】单施GA_(3)处理与清水对照相比,显著增加了苦荞的百粒重以及籽粒中腺苷二磷酸葡萄糖焦磷酸化酶和可溶性淀粉合成酶的活性、叶片的抗氧化酶活性、净光合速率、气孔导度和蒸腾速率,显著提高了单株及最终的产量。80 mg·L^(−1) GA3配施不同质量浓度的EBR处理时,随EBR施用量的增加,苦荞强势粒的淀粉合成酶活性、叶片抗氧化酶活性、光合特性、主茎分枝数、主茎直径、单株粒数、单株粒重和产量均表现为先增加后降低;苦荞的主茎节数和株高呈持续增加的变化趋势;弱势粒的淀粉合成酶活性则呈持续下降的变化趋势。【结论】赤霉素配施适宜的2,4-表油菜素内酯处理(80 mg·L^(−1) GA_(3)+0.5 mg·L^(−1) EBR)能促进苦荞强势粒的灌浆,延缓叶片衰老,提高粒重与最终的产量。

【Objective】Effects of gibberellic acid(GA3)and 2,4-ebrassinolide(EBR)on grain-filling and yield of Tartary buckwheat were studied.【Method】Grain-filling and starch synthase activity of dominant and weak Tartary buckwheat grains under 6 treatments of GA3 and/or EBR were compared.Antioxidant enzyme activity and photosynthetic properties of the leaves during grain-filling stage and agronomic traits associated with grain yield of the plants were monitored.【Result】Compared to control,GA3 alone significantly increased the 100-grain weight and activities of adenosine diphosphate glucose coke phosphorylase and soluble starch synthase in the grains as well as the antioxidant enzyme activities,net photosynthetic rate,stomatal conductance,and transpiration rate in the leaves.It also significantly increased the yield per plant and final grain yield.Increasing EBR application,on the other hand,increased the activities of starch synthase,leaf antioxidant enzymes,leaf photosynthetic characteristics,main stem branch number and diameter,grains per plant,grain weight per plant,and final grain yield initially but declined after reaching a peak.Meanwhile,the number of main stem nodes and plant height rose and the starch synthase activity of the weak grains lowered continuously.【Conclusion】By combining GA3 at the rate of 80 mg·L^(−1) and EBR at 0.5 mg·L^(−1) for treating Tartary buckwheat,the grain-filling of dominant grains was enhanced,the leaf senescence delayed,and the grain weight and final yield increased.