外源14-羟基芸苔素甾醇对桃座果率和果实品质的影响

Effects of exogenous 14-hydroxylated brassinosteroid on fruit set percentage and fruit quality of peach

为了应对低温座果率低导致桃树减产,该研究在桃树盛花期和幼果期喷施不同质量分数的芸苔素甾醇,研究其对桃树座果率的影响效果和合适作用质量分数。供试材料为桃品种‘中油金铭’,利用0.01%14-羟基芸苔素甾醇500倍液(高质量分数)和1000倍(低质量分数)液处理,以清水为对照,分别在桃树的盛花期和幼果期喷施2次,处理前统计花的数量,处理后每隔两周随机抽样,记录幼果数并统计座果率,至落花后第7周为止。果实成熟后测定果实品质相关的生理指标,包括果径、果核径、单果质量、果核质量、可溶性固形物含量及可滴定酸含量,通过方差分析确定芸苔素甾醇对果实品质的影响。结果表明,施用芸苔素甾醇可以显著提高桃树的座果率、单果质量和可溶性固形物含量,同时增加果核大小,降低可滴定酸含量。施用高质量分数和低质量分数芸苔素处理桃树后,座果率相比对照分别提升了83.40%和83.74%,单果质量分别增加了34.8%和46.5%,可溶性固形物含量分别提高了10.00%和23.44%,可滴定酸含量分别降低了16.46%和39.24%。喷施高质量分数的芸苔素甾醇可以提高桃果皮的光洁度,而低质量分数的芸苔素甾醇可能会降低桃果皮着色度。相关性分析表明,桃果皮的L值与a值呈现显著的正相关性,与b值呈现显著的负相关性,而与可溶性固形物和可滴定酸含量均无相关性。a值与可滴定酸含量成正相关,b值与可滴定酸含量成负相关,与可溶性固形物均无相关性。该研究为采用14-羟基芸苔素甾醇提高在低温逆境中桃树的座果率和提高果实品质提供了一定的理论依据。

To reduce the negative impact of low temperature on fruit set and yield of peach tree,the effects and optimal concentration of brassinolide(BR)application during the blooming and young fruit stages of the peach variety′Zhongyou Jinming′were studied.Two levels(500-fold and 1000-fold dilutions)of 14-hydroxylated brassinosteroid(0.01%)were used with water as CK.Two applications were made at each stage,and the number of flowers was counted before treatment.After treatment,the fruit set was recorded every two weeks,and fruit quality-related physiological indicators,including fruit diameter,pit diameter,fruit weight,pit weight,soluble solids content,and titratable acidity,were measured after the fruit matured.Analysis of variance was used to determine the effects of BR on fruit quality.The results showed that BR significantly increased fruit set,fruit weight,and soluble solids content while increasing pit size and decreasing titratable acidity.Compared to CK,high and low levels of BR increased fruit set by 83.40%and 83.74%,respectively,and increased fruit weight by 34.8%and 46.5%,respectively.Soluble solids content increased by 10.00%and 23.44%,respectively,and titratable acidity decreased by 16.46%and 39.24%,respectively.High-level BR application enhanced peach fruit surface smoothness while low-BR application could reduce fruit coloration.Correlation analysis showed a significant positive correlation between L and a values of the peach fruit skin and a significant negative correlation between L and b values,while L had no correlation with soluble solids content or titratable acidity.There was a positive correlation between a value and titratable acidity,and a negative correlation between b value and titratable acidity without correlation with soluble solids content.This study provides a theoretical basis for using 14-hydroxy lated brassinosteroid to improve fruit set and quality under low-temperature stress.