叶面喷硼对紫云英结实特性的影响

硼是植物生长发育所必需的微量元素,与植物的细胞与功能、花粉管发育伸长以及对光合作用的产物-碳水化合物的合成与转运有重要作用。本研究通过开花前叶面喷施硼肥,探讨硼肥对紫云英花荚结实成粒的调控效应,以期为增加紫云英籽粒数、提高种子产量调控技术应用提供参考。选取“信紫1号”为供试材料,在开花前叶面喷施清水(对照CK)、硼肥500 (T₁)、1000 (T₂)、2000 (T₃)、4000 (T₄)、6000 mg·L^-1(T₅)]。在成熟期,按常规考种法记载单位面积株数、分枝数、不同层花序的花序数、结荚数、籽粒数等指标。结果表明,各喷施浓度处理(除T₃处理外)的单位面积花序数、结荚数、单荚籽粒数和荚果结实率在不同层花序上与对照间差异均不明显。喷施浓度T₃处理的单位面积花序数在第3~6层花序上较对照分别提高31.87%、40.79%、37.49%和44.99%,单位面积结荚数较对照分别提高27.89%、32.69%、35.92%和25.84%,单荚籽粒数较对照分别提高20.69%、23.54%、23.24%和22.03%,荚果结实率较对照分别增加2.95%、2.56%、3.49%和4.51%,然而在第1和2层花序上与对照差异不明显。进一步分析产量构成发现,喷施不同浓度硼肥处理对紫云英单位面积有效株数、一级分枝数、单株一级分枝数和千粒重影响不大。综上,在紫云英花荚脱落开始之前叶面喷施2000 mg·L^-1硼肥,可显著促进第3~6层花序单位面积花序数、结荚数和单荚籽粒数的增加,从而促进荚果结实率的提高,最终获得较高的种子产量。

Effects of boron foliar spray on grain-setting characteristics of Chinese milk vetch (Astragalus sinicus)

Boron is an essential trace element for plant growth and development, with special functions in pollen tube elongation and the synthesis and transport of carbohydrates. The aim of this study was to determine the effect of applying boron as a foliar spray on flowering and the development of pods and grains, with an overall aim to increase the number of grains per pod and improve yield. The Chinese milk vetch cultivar “Xinzi No.1” was subjected to six different foliar application treatments; water (control) and borate solution (500 mg·L^-1, T₁; 1000 mg·L^-1, T₂; 2000 mg·L^-1, T₃; 4000 mg·L^-1, T₄; 6000 mg·L^-1, T₅), which were applied at the pre-flowering stage. When the plants reached the mature stage, the number of inflorescences, pods, grains per pod for different inflorescence positions (1 lowest on the raceme, 6 highest) and the number of plants and branches per unit area were determined using conventional test methods. The number of inflorescences and pods unit area, grain set rates of pods, and number of grains per pod for different inflorescence positions did not differ significantly between the control and the treatments, except for the T₃ treatment. In the 3rd to 6th inflorescence positions, the number of inflorescences per unit area was increased by 31.87%, 40.79%, 37.49%, and 44.99%, respectively; the number of pods per unit area was increased by 27.89%, 32.69%, 35.92% and 25.84%, respectively; the number of grains per pod was increased by 20.69%, 23.54%, 23.24%, and 22.03%, respectively; and the grain set rates of pods was increased by 2.95%, 2.56%, 3.49% and 4.51%, respectively, in the T₃ treatment as compared with the water control. However, these parameters in the 1st and 2nd inflorescence positions did not differ significantly between the T₃ treatment and the control. Further analyses showed that spraying boron at different concentrations had little effect on first-order branching and 1000-grain weight of Chinese milk vetch. Our results show that, when applied at the pre-flowering stage, a foliar application of boron (2000 mg·L^-1) can significantly increase the number of inflorescences, pods, and grains per pod per unit area at the 3rd to 6th inflorescence positions, thereby increasing the grain-setting rates of pods and increasing the grain yield of Chinese milk vetch.