外源喷施油菜素内酯对碱胁迫下甜菜生长的影响

为探究碱胁迫下不同质量浓度的油菜素内酯对甜菜生长的影响,在甜菜苗期喷施0.05mg·L-1、0.1mg·L-1、0.15mg·L-1和0.2mg·L-1不同质量浓度的油菜素内酯(BR),分析植株生长特性、光合能力、内源激素、块根产量和含糖率的变化,明确甜菜喷施的最佳质量浓度。结果表明,喷施不同质量浓度BR的处理的光合能力在整个生长期均大于碱处理,并在生长后期显著降低叶片ABA质量浓度,提高CTK和GA3的质量浓度,增加块根产量和产糖量。其中质量浓度为0.15mg·L-1的油菜素内酯处理效果最明显,块根产量最接近CK,达到CK的66.3%,是Alk(碱处理)的157.5%。苗期喷施适宜质量浓度的BR可以缓解碱土对甜菜生长的胁迫,增加干物质积累,增强甜菜的光合作用,降低叶片ABA与其他激素的比例,提高甜菜的抗碱能力。

Effects of Exogenous Application of Brassinolideon Sugar Beet Growth under Alkali Stress

In order to explore the effects of different mass concentrations of brassinolide on sugarbeet growth under alkali stress. Under alkaline stress,different mass concentrations (0.05 mg·L^-1,0.1 mg·L^-1,0.15 mg·L^-1,0.2 mg·L^-1) of brassinolide(BR ) were sprayed at the seedling stage of sugar beet. By analyzing the characteristics of plant growth,photosynthetic capacity,endogenous hormones,root tuber yield and sugar content,the optimum mass concentration of sugar beet was investigated. The results showed that spraying different mass concentrations of BR could improve the photosynthetic capacity of sugar beet under alkali stress,decrease the ABA mass concentrations,increase the mass concentrations of CTK and GA₃,increase the root yield and sugar content. The results showed that the photosynthetic ability of BR sprayed with different concentration of BR was higher than that of alkali treatment at the whole growth periods,and significantly decreased the ABA concentration of leaves at the late growth period. The root yield and sugar yield increased by increasing the mass concentration of CTK and GA₃,and the root yield was the most close to CK when the concentration was 0.15 mg·L ^-1. It reached 66.3% of CK,which was 157.5% of alkali treatment. Spraying BR with appropriate mass concentration at seedling stage could alleviate the stress of alkali soil on sugar beet growth and increase dry matter accumulation. With increase of photosynthesis and sugar beet.The ratio of ABA to other hormones in leaves was low,and the alkali-resistant ability of beet was improved.