【作者】 张嵩；

【导师】 张光伦；

【作者基本信息】 四川农业大学 ， 果树学， 2005， 硕士

【摘要】 采取田间生物学、生态学观测和室内生理生化测试相结合的综合分析法,对果实发育过程中影响脐橙和夏橙果实质地的关键酶活性变化动态、脐橙果皮和可食部分质地的关键酶活性变化动态、不同生境下果实质地的关键酶活性变化以及主要生态因子对果实质地的关键酶的影响等方面,进行了较全面系统的研究,结果表明: 1,在果实生长发育过程中,同一生境的脐橙和夏橙果实可食部分的多聚半乳糖醛酸酶(PG)活性总体都呈上升趋势。夏橙果实可食部分的PG活性出现高峰值比脐橙果实晚一个月左右;果皮的纤维素酶(Cx)活性变化,脐橙和夏橙总变化趋势基本一致,都是先上升后下降再上升再下降的变化规律;但夏橙果皮的Cx活性出现高峰值比脐橙果皮晚一个月左右,这符合夏橙果实生长期长的特性;并且夏橙和脐橙的果皮Cx活性在幼果期升高与此时的六月落果相关。 2,在果实生长发育过程中,同一生境的脐橙和夏橙果实,除幼果期的脐橙和夏橙果实可食部分的Cx活性都很低,几乎检测不到以外。花后85天以后,脐橙果实可食部分的Cx活性都显著高于夏橙,而且变化幅度比较大;夏橙可食部分的Cx活性低而且变幅比较平缓,这是夏橙果实质地差、不化渣的主要原因之一。 3,脐橙果实整个发育过程中,可食部分的PG和Cx活性均比果皮的活性高。花后55～70d(幼果期)果皮中Cx活性升高,而可食部分的Cx活性最低几乎为零。花后85～115d(果实膨大期)可食部分的Cx活性有所升高,可食部分的PG活性则快速上升,并且达到最大值。表明可食部分的PG和Cx活性在果实膨大期升高,对膨大期的果实细胞体积膨大所需果胶和纤维素的水解起到重要作用,特别是可食部分PG对果胶的水解尤为重要。花后130～175d(果实成熟初期)可食部分的Cx活性不断升高并达到最大值,这表明可食部分的Cx活性与脐橙果实早期起始软化有密切联系。 4,不同生境对脐橙果实可食部分的PG活性有极显著影响。花后115d左右(果实膨大期),不同生境下的脐橙果实可食部分的PG活性都达到最大值,因此可食部分的PG对膨大期果实细胞体积膨大所需果胶的水解起到重要作用。花后115d以后,不同生境下脐橙果实可食部分的PG活性表现为A型区的红格>B型区的江安>C型区的名山,这与脐橙果实主要质地品质指标在三型区的不同表现相一致,因此可食更多还原

【Abstract】 Applying two different orange varieties Robertson Navel Orange[Citrus sinesis(L)Osbeck] and Valencia Orange [Citrus sinesis(L)Osbeck] as testing materials, which had grafted on tangerine[C.reiculata] rootstock for 10 years. Using the methods of combining field biological and ecological investigation and indoor analysis, the activity changes of key enzymes related to sweet oranges texture during fruit growth, the activity changes of key enzymes which effect on texture of the peel and pulp, the comparisons of key enzymes related to Navel Orange texture in different habitats, the effects of ecological factors on key enzymes related to Navel Orange texture were studied, the result showed:1. During the course of fruit developing and maturating, Polygalacturonase (PG) activity of sweet orange rose constantly in the same habitat. PG activity of navel orange pulp reached maximum earlier than Valencia Orange about one month. Cellulase(Cx) activity of sweet orange peel rose firstly and then decreased rapidly during fruit growth. But Cx activity of navel orange peel reached maximum earlier than Valencia Orange about one month and Cx activity of sweet orange were increased at young stage.2. During the course of fruit developing and maturating, Cx activity of sweet orange pulp were low at young stage. Cx activation of navel orange pulp is higher than Valencia Orange from 85days after anthesis to 220 days after anthesis.3. Cx and PG activation of pulp is higher than peel during navel orange fruit growth. Cx activation of peel rose while Cx activation of the pulp is the lowest at young stage. From 85 days after anthesis to 115 days after anthesis, PG activation of pulp reached maximum while Cx activation of pulp began to rise, which indicated that Cx and PG activation of pulp play an important role at expand stage. Especially the function that PGof pulp effect on hydrolysis of pectin is particularly important. Cx activation of pulp rose constantly and reached maximum froml30 days after anthesis to 175 days after anthesis.4, In different habitats, PG activation of navel orange pulp showed much difference each other. In different habitats, PG activation of navel orange pulp reached maximum at expand stage. From 115 days after anthesis to 220 days after anthesis, PG activation of navel orange pulp keep the same with the texture index of navel orange in different habitats. PG of the navel orange pulp is one of the enzymes effect on the texture index of navel orange.5, In different habitats, Cx of navel orange pulp had a significant difference in activity. After 100 days after anthesis, Cx activation of navel orange pulp at Hong’ge is higher than Jiang" an and Ming’shan notably. In different habitats, Cx activation of navel orange pulp is one of the main factors of influencing the remarkable difference of fruit digest residue at fruit ripening stage.6, In different habitats, PG of navel orange peel had a significant difference inactivity. From 115 days after anthesis to 190 days after anthesis, PG activation of navel orange peel keep the same with the texture index of navel orange in different habitats. It indicated that PG of the navel orange peel is one of the enzymes effect on the skin thickness of navel orange in different habitats.7, Through the gray system analysis of 3 ecological factors to the key enzymes activity, the results showed that the factors which influenced the key enzymes activity were more seriously were sunshine and temperature. Sunshine is the greatest factor influencing the activation of PG and Cx of navel orange pulp at fruit expand stage. Temperature is the greatest factor of effect key enzymes activity at fruit ripening stage. Mean relative humidity is not the important factors influencing the activation of PG and Cx of navel orange pulp during fruit growth. But from 40 days after anthesis to 130 days after anthesis, mean relative humidity is the important factors influencing the activation of PG of navel orange peel. This maybe one of the reasons Hong’ge navel orange peel is thick.更多还原