纽荷尔脐橙疑似耐寒突变体的初步鉴定与评价  

Preliminary identification and evaluation of putative cold-resistant mutant in Newhall Navel orange

作　　者：邹巧玲 李娜[1,2] 闫于烟 郭杰 王驰 黄伟 龚玲 龙桂友 ZOU Qiaoling;LI Na;YAN Yuyan;GUO Jie;WANG Chi;HUANG Wei;GONG Ling;LONG Guiyou(Horticulture College,Hunan Agricultural University,Changsha 410125,Hunan,China;National Center for Citrus Improvement(Changsha),Changsha 410125,Hunan,China)

机构地区：[1]湖南农业大学园艺学院,长沙410125 [2]国家柑橘改良中心长沙分中心,长沙410125

出　　处：《果树学报》2022年第7期1183-1190,共8页Journal of Fruit Science

基　　金：湖南省科技厅重点研发项目(2019NK2051);湖南省教育厅重点项目(20A231);湖南省水果产业技术体系柑橘育种岗位专项。

摘　　要：【目的】鉴定纽荷尔脐橙疑似耐寒突变体是否发生了遗传性状变化,评价其耐寒能力是否较野生型增强。【方法】以纽荷尔脐橙突变体与野生型为试材,观测比较春梢叶片性状和果实外观性状,分析比较果实内在品质,应用SSR分子标记鉴定遗传变异,石蜡切片观测比较叶片组织结构,分析比较-6℃低温处理叶片的电解质渗出率、脯氨酸含量、超氧化物歧化酶活性等抗寒性相关指标。【结果】纽荷尔脐橙突变体春梢叶片、翼叶、叶柄等性状,果实形状、果皮颜色、果实大小、油胞等性状与野生型没有差异;果实含酸量连续2 a(年)较野生型低24.7%~38.6%;1对SSR引物扩增显示突变体与野生型在250 bp左右存在2条差异带;突变体叶片细胞结构紧密度、栅栏组织与海绵组织厚度的比值均极显著大于野生型;突变体叶片的电解质渗出率未低温处理以及-6℃处理2~10 h均低于野生型,-6℃处理8 h的电解质渗出率相当于野生型叶片-6℃处理6 h的水平;突变体叶片中脯氨酸含量极显著高于野生型,-6℃低温处理使突变体与野生型叶片脯氨酸含量差异增大;突变体超氧化物歧化酶活性未低温处理(0 h)和低温处理2 h至10 h均显著高于野生型。【结论】该突变体可能是果实含酸量较低,耐寒性增强,DNA水平发生了遗传改变的纽荷尔脐橙芽变。【Objective】Citrus is a perennial woody plant with a long growth cycle, and once freezing damage occurs, it will cause irreparable loss to the industry. It is difficult to breed cold-resistant cultivar by conventional breeding and marker-assisted breeding in citrus for its long cycle of polyembryonic and sexual generations. Most commercial cultivars of citrus were selected from bud mutants. The mutations obtained after low temperature and freezing injury are very valuable for breeding new cold-resistant citrus varieties. The mutant used in this study was a branch without obvious cold damage under freezing injury of grade 3-4, and it was found by our research group in a Newhall orchard, which was highly likely to be a cold-resistant mutant of Newhall navel orange and was preserved in the Changsha Branch of National Citrus Improvement Center. In this paper, it was an attempt to identify whether the suspected cold-resistant mutant of Newhall navel orange had changes in hereditary characteristics and to evaluate whether the cold-resistant ability is enhanced, compared with the wild type.【Methods】Genetic variation of mutants was mainly identified by a combination of morphological and SSR-molecular-markers.Morphological and structural observation can easily and visually reveal the genetic differences of mutants, while SSR molecular markers can quickly and stably detect the differences between the mutant and wild-type at DNA levels. For two consecutive years, the leaf and fruit appearance traits of the highgrafting mutants were observed to analyze and the fruit quality traits were also compared. The DNA level was identified using SSR molecular markers to investigate the genetic variation between the mutant and the wild type. The evaluation of cold resistance adopted the method of laboratory identification that was less restricted than field identification. The tissue structure characteristics of leaves were observed by paraffin section, and the electrolyte leakage rate s, proline content and superoxide dismutase

关 键 词：脐橙 抗寒 突变体 SSR分子标记 叶片组织结构 电解质渗出率 脯氨酸 超氧化物歧化酶 

分 类 号：S666.4[农业科学—果树学]