【作者】 李玲；

【导师】 蔡永萍；

【作者基本信息】 安徽农业大学 ， 果树学， 2004， 硕士

【摘要】 石细胞是梨果实所特有的，它是影响梨果实品质的关键因素之一。砀山酥梨是我国华北、西北、黄河故道等地区的主栽品种。由于砀山酥梨外形美观、风味好，营养价值高、耐贮藏、供应时间长，因此深受人们所喜爱，为我国梨出口的主要品种之一。但近年来，由于品种退化或栽培管理不善等原因，砀山酥梨的石细胞含量增多，果肉变粗，口感多渣，严重影响了砀山酥梨的风味和品质。本实验以安徽省砀山果园场40年生砀山酥梨为试材，在4种光照条件下，对砀山酥梨生长发育过程中石细胞发育过程、内源激素（IAA、ZR、ABA）、酶（POD、PAL、PPO）和矿质元素（Ca2+、Zn2+）的变化等方面进行了研究。目的是阐明砀山酥梨石细胞形成的生理代谢基础，揭示影响砀山酥梨石细胞形成的因素，为砀山酥梨在生产上采用合理的栽培技术来减少砀山酥梨石细胞含量，提高砀山酥梨品质提供理论依据。主要研究结果如下：1.砀山酥梨果实生长发育过程中，果实鲜重及纵、横径增长均为慢-快-慢的S型曲线，其中前两期是砀山酥梨果实产量和品质形成的关键时期。2.通过对砀山酥梨果实石细胞发育过程的研究表明，石细胞是由梨果实的薄壁细胞的细胞壁加厚，继则木质化而形成的。砀山酥梨果实的细胞分裂期是石细胞形成的主要时期，砀山酥梨石细胞形成的最高峰在梨花后第7周，其直径最大值出现于梨花后第11周，石细胞的形成于梨花后第11周停止。因此，在栽培生产中，采取适当的农业措施来控制和减少梨石细胞形成，提高梨品质，关键应在梨果实细胞分裂期前采取措施。3.随着梨果实的发育，梨果实内源激素（ZR、IAA、ABA）均有两次高峰期。ZR、IAA、ABA的最高峰均出现在果实盛花后第1周，ZR与IAA在梨花后第7周均有另一小高峰出现，而ABA则在梨花后第20周出现另一小高峰。结果表明，ZR、IAA参与了梨果实细胞分裂与膨大，ABA则是前期促进砀山酥梨果实的对同化物吸收，后期刺激果实成熟。通过对不同光强下砀山酥梨果实内源激素的比较研究，结果为高光强>中光强>弱光强>极弱光强，这表明强光有利于砀山酥梨内源激素（ZR、IAA、ABA）的合成。因此，光强可能是通过刺激梨果实内源激素合成来抑制石细胞形成的。4.砀山酥梨发育过程中矿质元素Ca2+、Zn2+变化特点为：Ca2+、Zn2+两次浓度的高峰期均出现于梨花后第1与第7周，这说明Ca2+、Zn2+对砀山酥梨果实幼果生长发育具有重要作用。Ca2+、Zn2+对砀山酥梨石细胞的形成有抑制作用。不同光强下Ca2+、Zn2+的浓度均表现为高光强>中光强>弱光强>极弱光强。 <WP=4>5.砀山酥梨果实生长发育过程中PAL、POD、PPO活性高峰期均出现于砀山酥梨幼果期（梨花后第1-7周），后随果实发育迅速下降。研究表明，PAL、POD、PPO对砀山酥梨的石细胞形成有促进作用。6.通过对不同光强下砀山酥梨石细胞含量的测定，结果为高光强<中光强<弱光强<极弱光强。这表明强光可抑制石细胞的形成。从砀山酥梨发育过程中内源激素（IAA、ZR、ABA）、酶（POD、PAL、PPO）和矿质元素（Ca2+、Zn2+）的变化研究结果可知，光强对石细胞形成的抑制是通过影响这些内部的生理因素而作用的。7.通过对不同光强下砀山酥梨的品质研究表明，在强光部位梨果实品质好，高光强>中光强>弱光强>极弱光强。光强对砀山酥梨品质的影响主要是通过前期对石细胞的形成影响，后期促进糖的积累，提高糖酸比，改善梨品质。更多还原

【Abstract】 The stone cell, a characteristic construction in fruit of pears, is one of pivotal factors affecting the quality of pear fruit. Dangshan pear is the main variety planted in northern and Northwest China, ancient channel of Yellow River. Because of nice shape, good flavor, high nutrition value and durable store, Dangshan pear is not only favored extensively, but it is one of the chief pear kinds exported in China. Recently years, due to species degeneration or poor management of cultivation, Dangshan pear stone cell content was becoming more and more, pulp became crude and poor edible quality, which affected seriously the quality of Dangshan pear. Dangshan pears of forty years old planted in Dangshan fruit garden of Anhui province were used as experiment material. Stone cell developing process, changes of endogenous hormone (ZR, IAA, ABA), enzymes (POD, PPO, PAL) and mineral elements etc during growth and development of Dangshan pear under four kinds of light intensities were studied. The purpose is to illuminate the base of physiological metabolism of Dangshan pears’ stone cell formation and to reveal the factors affecting the formation of the stone cell, which would provide the theoretical gist in adopting reasonable planting technology in order to decrease the stone cell content of Dangshan pear and improve the quality of Dangshan pear during planting management. Main results were as follows:1.The increase of fruit fresh weight, vertical and horizontal size represent slowing-fasting-slowing model like “s” curve. The two proceeding phase of the growth of Dangshan pear were the primary period of the formation of its yield and quality.2.The research on the stone cell growing indicated that the stone cell was formed through the thin cell wall thickening and lignifying. The period of Dangshan pear fruits cell abruption is the pivotal period of the stone cell forming. The peak of the stone cell formation of Dangshan pear is the seventh weeks after flowering and the longest diameter of stone cell appears at the eleventh weeks after flowering. Termination of the stone cell development is the eleventh weeks after flowering. Suitable agriculture measures before <WP=6>stone cell abruption could control and decrease the formation of stone cell and improve quality of Dangshan pear. 3.During growth and development of Dangshan pear, endogenous hormone (ZR, IAA and ABA) content had two peaks. The highest content time of ZR、IAA and ABA appeared at the first week after blooming. Another peak of ZR and IAA appeared at the seventh week after blooming. But the other peak of ABA content appeared at the twenty weeks after blooming. These results showed that ZR and IAA took part in the pear fruit cell abruption and expanding, when, ABA promoted Dangshan pear absorbed assimilative substance in early period, and stimulated the fruit ripe in late period. The result of comparative study on endogenous hormone content under different light intensity indicated that the content was the highest under high light intensity, the middle light intensity was higher, the thin light intensity was followed, and the thinnest light intensity was worst, which showed light intensity was favor to synthesize endogenous hormone of Dangshan pear. Light intensity may stimulate synthesis of endogenous hormone to reduce the stone cell forming.4.The character of mineral elements (Ca2+, Zn2+) changing of fruit during Dangshan pear growth and development was that the two peak of Ca2+ and Zn2+ content appeared at the first and seventh week after pear flowering. This showed Ca2+ and Zn2+ have important function on the unripe growing, and they can restrain the form of the stone cell. The result of comparative study on Ca2+ and Zn2+ content under different light intensity indicated that light intensity was higher, Ca2+ and Zn2+ content was higher.5.During growing of Dangshan pear, enzyme (POD, PPO, PAL) activity of fruit at the prophase is higher than anaphase. The result showed POD and PPO and PAL promoted the form of the stone cell of Dangshan pear.6.The更多还原