钾肥施用对菜用大豆生殖生长期可溶性糖含量及产量的影响

Effect of Potassium Fertilizer Application on Soluble Sugar Content During Reproductive Stages and Yield in Vegetable Soybean

菜用大豆籽粒可溶性糖含量是评价其食用品质的重要指标,为探究钾素影响菜用大豆“源”、“库”端可溶性糖转化关系,在正常氮、磷种肥施用基础上,以菜用中科毛豆1号和品系121为材料,进行不施钾（K0）、种肥施钾120kg·hm^-2（K1）以及种肥施钾120 kg·hm^-2＋花期和结荚期两次喷施钾叶面肥（K2）处理,探讨植株不同部位可溶性糖积累规律。结果表明：种肥施钾显著增加菜用大豆生殖生长期（开花后4～8周）叶片、荚皮、籽粒中可溶性糖含量,在此基础上于花期、荚期两次喷施叶面钾肥有利于可溶性糖在叶片、荚皮、籽粒中的进一步积累。开花后7周（最佳采食期）时,籽粒可溶性糖含量达到最大,此时中科毛豆1号K1、K2处理相比K0处理分别高29.2%和37.5%,而品系121分别高9.3%和24.8%。同时发现,钾肥施用显著提高了菜用大豆鲜荚采食期产量,中科毛豆1号K1、K2处理的单株鲜荚产量相比K0处理分别高8.2%和37.1%,而品系121分别高18.9%及31.6%。钾肥施用可能通过增强菜用大豆源端（叶片）可溶性糖的供应以及促进荚皮可溶性糖的运转量而对籽粒中可溶性糖的积累起到促进作用。

Soluble sugar content is an important indicator of the evaluation of the eating quality of vegetable soybean, this experiment was going to find out the effect of potassium fertilizer on soluble sugar content in vegetable soybean. Three potassium fertilizer treatments were treated with no potassium fertilizer （K0）, 120 kg·ha^-1K （K1） at seeding, 120 kg· ha^-1 K with additional foliar application of 30 kg·ha^-1 of K2 SO4 （K2） at flowering-podding. We discussed the soluble sugar content in leaf, pod shell and seed during reproductive stages and yield in two vegetable soybean genotypes （ ＇ Zhongkemaodou 1 ＇ and ＇ Line 121＇ ） under normal N and P fertilizers application by pot experiment. Potassium application significantly increased the solu- ble sugar content in each part of vegetable soybean during reproductive stages. Maximum soluble sugar contents were all ob- tained at K2 treatment. Compared with control, the seed soluble contents of ＇ Zhongkemaodou l ＇ at 7 weeks ＇after flowering, were increased by 29. 2% and 37.5% in K1 and K2 treatments; while ＇ Line 121＇ were increased by 9.3% and 24. 8% respectively. As to fresh pod yield of vegetable soybean, compared with control, ＇ Zhongkemaodou 1 ＇ increased by 8.2% and 37. 1% in K1 and K2 treatments; while ＇Line 121＇ increased by 18.9% and 31.6%, respectively. Rational application of potassium fertilizer significantly increased soluble sugar content and fresh pod yield of vegetable soybean. The increased seed soluble sugar content by potassium fertilizer application was due to enhanced accumulation of soluble sugar in leaves and pod shells.