苹果3个早熟品种果实发育后期硬度及其相关生理指标的初步研究

Preliminary Study on Firmness and Related Physiological Indices of Three Early-ripening Apple Cultivar During Late Development of the Fruit

以‘泰山早霞’、‘极早红’和‘辽伏’3个早熟苹果品种为试材,研究果实发育期间果实硬度、细胞壁水解酶及淀粉酶活性、乙烯释放量的变化,旨在为探讨果实软化机理提供基本资料,并为早熟苹果品种软化的调控奠定基础。结果表明:①3个参试品种果实发育过程中果实硬度基本均呈下降趋势,但品种间下降的幅度存在明显差异,其中‘辽伏’花后75d硬度的下降幅度为35%,‘泰山早霞’50%,‘极早红’53%;②3个品种果胶甲酯酶(PE)和淀粉酶(Amylase)活性差异不明显,‘泰山早霞’、‘极早红’的多聚半乳糖醛酸酶(PG)、纤维素酶(Cx)活性明显高于‘辽伏’,3个品种PG酶、Cx酶活性变化与其果实硬度变化呈显著负相关;③3个参试早熟苹果品种果实发育过程中,乙烯释放量与PG酶、Cx酶活性呈显著正相关。

In order to study the mechanism of softening in early-ripening apple cultivars,the fruit hardness,activities of amylase,cell wall hydrolysis enzymes and ethylene production were compared among three early-ripening apple cultivars.The results indicated that：① The fruit hardness of the three cultivars decreased during fruit development,however,in 75 days after blooming date the declining ranges were different in the three cultivars.The declining range of＇Liaofu＇was 35% while that of＇Taishan Zaoxia＇and＇Jizaohong＇were 50% and 53%,respectively;②Activity of PE and amylase of the three cultivars showed little differences.The activities of PG and Cx in＇Taishan Zaoxia＇and＇Jizaohong＇were significantly higher than that of＇Liaofu＇,and the activities of PG and Cx in the three cultivars were negatively correlated with fruit hardness;③ Ethylene production was positively correlated with the activity of PG and Cx during fruit development.