喷施烯效唑对甜荞茎秆抗倒性能及产量的影响

【目的】甜荞(Fagopyrum esculentum M.)被誉为21世纪人类的绿色食品之一。倒伏是制约甜荞产量和品质的重要因素。研究喷施不同浓度的烯效唑对甜荞茎秆抗倒性能的影响,为甜荞的抗倒伏栽培提供理论依据。【方法】试验于2013—2014年在西南大学歇马科研基地进行,采用随机区组设计,以中抗甜荞品种"宁荞1号"为试验材料,设置0(CK)、25 mg·L~(-1)(T1)、50 mg·L~(-1)(T2)、75 mg·L~(-1)(T3)和100 mg·L~(-1)(T4)5个烯效唑浓度处理,于4叶期按100 mL·m~(-2)进行叶面喷施。分别于开花期、灌浆期和成熟期对茎秆抗折力、倒伏指数、茎秆形态特性和茎秆解剖结构等指标进行测定分析,并于成熟期调查倒伏习性和产量。【结果】(1)茎秆抗折力、茎壁厚度和维管束面积从开花期至成熟期呈先增加后减小的变化趋势,在灌浆期达最大值;倒伏指数、株高、茎秆重心高度、茎秆鲜重、基部第2节间长、基部第2节间粗、机械组织厚度和维管束数目从开花期至成熟期逐渐增加;第2节间干重、节间充实度和机械组织层数从开花期至灌浆期逐渐增加,而后变化不明显。(2)产量、茎秆抗折力、基部第2节间粗、基部第2节间干重、节间充实度、机械组织层数、机械组织厚度、茎壁厚度、维管束数目和维管束面积在CK-T3处理浓度下表现为随浓度的增加而增加,在T3-T4处理浓度下表现为随浓度增加而降低;倒伏率、倒伏指数、株高、茎秆重心高度、茎秆鲜重、基部第2节间长在CK-T3处理浓度下表现为随浓度的增加而降低,在T3-T4处理浓度下表现为随浓度增加而增加。(3)与CK相比,T1、T2、T3和T4处理的产量分别增加了2.3%、6.5%、21.3%和11.3%,倒伏率分别降低了17.9%、40.7%、84.0%和60.5%。(4)不同烯效唑浓度处理间,茎秆抗折力、倒伏指数、茎秆形态特性和茎秆解剖结构均存在显著差异。产量与株高、茎秆重心高度、茎秆鲜重和基部第2节间长、倒伏指数及倒伏率呈极显著负相关,与基部茎秆第2节间粗、基部第2节间干重、节间充实度、机械组织层数、机械组织厚度、茎壁厚度、维管束数目和维管束面积及茎秆抗折力呈极显著正相关。茎秆抗折力、基部第2节间粗、基部第2节间干重、节间充实度、机械组织层数、机械组织厚度、茎壁厚度、维管束数目和维管束面积表现为T3T4T2T1CK,倒伏指数、株高、茎秆重心高度、茎秆鲜重和基部第2节间长表现为CKT1T2T4T3。结论]本试验条件下,当烯效唑喷施浓度为75 mg·L~(-1)时,能有效优化甜荞茎秆结构,改善茎秆质量,减小倒伏发生风险,增加产量。研究结果为甜荞的抗倒伏栽培奠定了基础。

Effects of Spraying Uniconazole on Lodging Resistance of Culm and Yield in Common Buckwheat

【Objective】Common buckwheat (Fagopyrum esculentum M.) has been praised as one of the green foods of human beings in the 21st century. Lodging is an important factor which limiting common buckwheat yield and quality worldwide, so exploring the effects of spraying uniconazole of different concentrations on culm could provide a theoretical basis for lodging resistance cultivation of common buckwheat. 【Method】 The field experiments were conducted as a randomized block design in 2013 and 2014 at the Xiema Experimental Station, Southwest University, China. Ningqiao 1, a moderate lodging resistance cultivar of common buckwheat, was used in this study. 0 mg·L^-1 (CK), 25 mg·L^-1 (T1), 50 mg·L^-1 (T2), 75 mg·L^-1 (T3), and 100 mg·L^-1 (T4) uniconazole were sprayed at the rate of 100 mL·m^-2 on common buckwheat leaf surfaces at the four-leaf stage. The culm snapping resistance, lodging index, culm morphology characteristics, and culm anatomical structure were measured and analyzed at the anthesis stage, filling stage, and maturity stage, respectively. The lodging behavior and yield were investigated at the maturity stage.【Result】The culm snapping resistance, culm wall thickness, and vascular bundle area increased and then decreased from the anthesis stage to maturity stage, and their maximum values appeared in the filling stage. The lodging index, plant height, culm gravity height, culm fresh weight, basal 2nd internode length, basal 2nd internode diameter, mechanical tissue thickness, and vascular bundle number increased from the anthesis stage to the maturity stage. The basal 2nd internode dry weight, filling degree, and mechanical tissue layer number increased from the anthesis stage to the filling stage, but then changes were not obvious. The yield, culm snapping resistance, basal 2nd internode diameter, basal 2nd internode dry weight, filling degree, mechanical tissue layer number, mechanical tissue thickness, culm wall thickness, vascular bundle number, and vascular bundle area increased with the increase of the concentration of uniconazole in the condition of CK-T3 treatments, while decreased with the increase of the concentration of uniconazole in the condition of T3-T4 treatments. The lodging percentage, lodging index, plant height, culm gravity height, culm fresh weight, and basal 2nd internode length decreased with the increase of the concentration of uniconazole in the condition of CK-T3 treatments, while it increased with the increase of the concentration of uniconazole in the condition of T3-T4 treatments. Compared with the control, the yield under the T1, T2, T3 and T4 treatments increased by 2.3%, 6.5%, 21.3%, and 11.3%, respectively, and the lodging percentage decreased by 17.9%, 40.7%, 84.0%, and 60.5%, respectively. There were significant differences in culm snapping resistance, lodging index, culm morphological structure, and culm anatomical structure among different treatments of uniconazole concentration. Plant height, culm gravity height, culm fresh weight, basal 2nd internode length , lodging index, lodging percentage were significant and negatively correlated with the yield. However, the basal 2nd internode diameter, basal 2nd internode dry weight, filling degree, mechanical tissue layer number, mechanical tissue thickness , culm wall thickness, vascular bundle area, vascular bundle number and culm snapping resistance are significantly and positively correlated with the yield. The culm snapping resistance, basal 2nd internode diameter, basal 2nd internode dry weight, filling degree, mechanical tissue layer number, mechanical tissue thickness, culm wall thickness, vascular bundle number, and vascular bundle area showed a trend of T3＞T4＞T2＞T1＞CK, while the lodging index, plant height, culm gravity height, culm fresh weight, and basal 2nd internode length showed a trend of CK＞T1＞T2＞T4＞T3.【Conclusion】In this research, when uniconazole was sprayed 75 mg·L^-1, the culm structure could be optimized effectively, the culm quality improved, the lodging risk decreased and the yield of common buckwheat was enhanced. The result would lay a foundation of lodging resistance cultivation of common buckwheat.