柑橘2个三倍体果实囊衣发育与化渣性评价

Evaluation of Fruit Segmental Membrane Development and Mastication in Two Citrus Triploids

探讨柑橘倍性杂交三倍体后代及其二倍体母本果实化渣性差异及原因,为柑橘三倍体果实化渣相关研究奠定数据基础。以本地早橘和红橘为对照,分别对以其为母本与四倍体倍性杂交获得的2个三倍体有性后代果实囊衣发育过程中的厚度变化和组分含量进行分析,探究囊衣结构及其成分对化渣性的影响。结果表明:2个三倍体后代果实囊衣厚度、细胞层数、硬度和剪切力在不同发育时期均显著大于其二倍体母本;与二倍体母本相比,2个三倍体后代囊衣细胞壁更厚,微纤丝密度更大,结构更紧密;囊衣的纤维素、半纤维素、水溶性果胶和原果胶含量均显著高于其二倍体母本,木质素含量则在部分发育时期显著低于二倍体母本。综上所述,果实囊衣厚,纤维素、半纤维素和果胶含量高可能是柑橘部分三倍体化渣性较差的主要原因,而这些指标可用于三倍体化渣性的评价和筛选。

To investigate the reason for the fruit mastication difference between citrus triploid progeny with their diploid parents,two triploid hybrids derived from the crosses with Bendizao tangerine and Red tangerine as female parent were selected as materials to investigate the effect of segmental membrane structure and its components on the mastication of triploid fruits comparing with their diploid parents.In this study,using the two diploid parents as the control,the fruit mastication of the two triploid hybrids was firstly determined with texture analyzer at mature stage.It showed that the hardness and shear force of the segmental membrane of the two triploid progenies were significantly higher than that of their diploid parents,indicating that the segmental membranes of the two triploid hybrids might thicker than that of their corresponding diploid parents.It showed that the thickness and cell layer number of the segmental membranes of the two triploid hybrids were significantly higher than that of their corresponding diploid parents at the same developmental stage started from 120 days after flowering(DAF).The ultrastructure of the segmental membrane showed that the cell walls in the two triploid hybrids were thicker and the cellulose microfibrils were denser than those of their diploid parents.The content of water-soluble pectin,protopectin,cellulose and hemicellulose in the segment membrane of the two triploid hybrids were significantly higher than that of their diploid parents,while the lignin content was significantly lower at some developmental stage.In conclusion,segmental membrane thickness,water-soluble pectin,protopectin,cellulose and hemicellulose contents are important factors affecting the mastication of some citrus triploid hybrids,providing some useful evaluation indexes to screen superior triploid lines with good fruit mastication quickly from a large-scale triploid population.