草业学报2016，Vol.25Issue(10)：153-162,10.DOI:10.11686/cyxb2016144
不同施钾量对苜蓿碳水化合物含量及抗蓟马的影响
Effects of potassium application rates on carbohydrate content and resistance to thrips (Thripidae)in alfalfa
摘要
Abstract
The aim of this research was to investigate the effects of potassium on alfalfa growth and its resist-ance to thrips.Two alfalfa varieties were chosen for the study;Gannong No.9 (thrip-resistant)and Gannong No.3 (thrip-susceptible).Potassium (K2 O)was applied to field-grown plants at five different levels (0,6,9, 12,and 15 g/m2 )during the peak thrip damage period,and then the damage index,the potassium and carbo-hydrate contents in leaves,and yield were evaluated.The results showed that the yields of both alfalfa varieties increased significantly with increasing K2 O levels.The potassium,soluble sugars,starch,and lignin contents in old and heart leaves increased with increasing K2 O levels,and the thrip damage index decreased significant-ly.The lowest damage index values were in the 9 g/m2 K2 O treatment (decreased 47.60% and 46.11% for Gannong No.9 and Gannong No.3 with the control,respectively).The damage index,yield,and potassium, soluble sugars,starch,and lignin contents at the second cutting showed similar trends to those at the third cut-ting.The damage index at the third cutting was decreased 30.78% and 23.27% for Gannong No.9 and Gan-nong No.3 with the control,respectively.Correlation analyses indicated that the potassium content of plants at the second and third cuttings was significantly negatively correlated with the damage index when the K2 O appli-cation rate was lower than 9 g/m2 ,but not significantly correlated with the damage index when the K2 O appli-cation rate was higher than 12 g/m2 .The damage index was lower in Gannong No.3 treated with potassium than in Gannong No.9 without potassium application.These results indicate that potassium can enhance the re-sistance of alfalfa to thrips by promoting the synthesis of carbohydrates (especially soluble sugars and starch) and plant growth.Therefore,potassium management is an effective method to increase the tolerance of alfalfa to thrips in the field.The most economical fertilizer application rate was 9 g K2 O/m2 in this experiment.关键词
苜蓿/钾元素/蓟马/抗虫性/碳水化合物Key words
Medicago sativa/potassium/thrips/insect resistance/carbohydrate引用本文复制引用
张晓燕,王森山,李小龙,李亚娟,胡桂馨..不同施钾量对苜蓿碳水化合物含量及抗蓟马的影响[J].草业学报,2016,25(10):153-162,10.基金项目
国家自然科学基金项目（31260579）和国家现代农业产业技术体系建设专项（CARS-35）资助。 （）
