柠檬合子胚自交实生苗的鉴定及其对柑橘溃疡病的抗性初步评价  

Identification of Lemon Zygotic Self-Crossed Seedlings and the Primary Evaluation of the Resistance to Citrus Canker Disease

作　　者：谭李梅 符红艳[1,2] 徐静 朱志媚[1,2] 胡哲 肖顺元 马先锋[1,2] 邓子牛[1,2] Tan Limei;Fu Hongyan;Xu Jing;Zhu Zhimei;Hu Zhe;Xiao Shunyuan;Ma Xianfeng;Deng Ziniu(College of Horticulture,Hunan Agricultural University,Changsha,410128;National Center for Citrus Improvement,Changsha,410128;University of Maryland Life Science and Technology College,Maryland,20850,USA)

机构地区：[1]湖南农业大学园艺学院,长沙410128 [2]国家柑橘改良中心长沙分中心,长沙410128 [3]马里兰大学生命科学与技术学院,美国马里兰20850

出　　处：《分子植物育种》2020年第7期2258-2267,共10页Molecular Plant Breeding

基　　金：国家自然科学基金重点国际合作研究项目(31720103915)资助。

摘　　要：枸橼C-05是抗溃疡病的柑橘种质资源,柠檬是枸橼的后代,其自交后代可能继承枸橼的抗性基因。为分析柠檬自交群体对柑橘溃疡病的抗感性规律,本研究建立了433株的‘尤力克’柠檬自交后代群体,并利用SSR分子标记对合子胚实生苗进行了鉴定,观察合子胚实生苗和珠心胚实生苗叶片形态学的差异,对所有自交后代离体注射接种柑橘溃疡病菌,初步评价了实生后代对柑橘溃疡病的抗病性差异。结果表明‘尤力克’柠檬存在多胚性,从300对SSR引物中筛选到8对可用于‘尤力克’柠檬合子胚鉴定的引物,共鉴定出合子胚实生苗57株,确定珠心胚实生苗4株。叶形指数、叶尖指数、翼叶长、翼叶宽和叶柄长均不能作为区分‘尤力克’柠檬合子胚实生苗与珠心胚实生苗的形态学标记,但合子胚实生苗的翼叶长度变异幅度大于珠心胚。57株合子胚实生苗离体接种柑橘溃疡病菌后,5株表现为抗病,52株表现为感病;4株珠心胚实生苗均表现为感病;在372株未鉴定清楚的自交后代中,8株表现为抗病,364株表现为感病。本研究表明利用SSR分子标记还不能完全鉴定出‘尤力克’柠檬合子胚植株,可能需要更多的引物或更灵敏的分子标记才能把全部实生后代鉴定出来。利用合子胚自交后代接种鉴定,更有利于分析‘尤力克’柠檬对柑橘溃疡病的抗感性遗传规律,挖掘抗性基因,为柠檬的抗病育种提供种质资源。It is reported that Citron C-05 is resistant to citrus canker disease,and lemon is the descendant of citron,thus the lemon self-crossing progenies may possess the resistance genes inherited from citron.In order to analyze the resistance of lemon self-crossing progenies to citrus canker disease,a population of 433 self-crossed’Eureka’lemon progenies was established.SSR markers were used to identify zygote seedlings,and leaf morphological characteristics were compared between zygotic and nucellar seedlings.All self-crossing seedlings were inoculated with the pathogen(Xanthomonas citri subsp.citri)by infiltration in detached leaves.From 300 pairs of SSR primers,8 primers were chosen for the identification of zygotic seedlings,57 zygotic seedlings and 4 nucellar seedlings were identified.Leaf shape index,leaf tip index,wing length,wing width and petiole length were not distinguishable between’Eureka’lemon zygotic and nucellar seedlings,even though the variation of leaf length of zygotic seedlings was more evident than that of nucellar ones.Among the 57 zygote seedlings inoculated with the pathogen,5 showed resistance and 52 were susceptible.4 nucellar seedlings were susceptible.Nevertheless,8 seedlings turned out to be resistant form the 372 self-crossing individuals which are not identified as zygotic or nucellar seedlings.This study demonstrated that SSR molecular markers used are not sufficient to identify all the zygotic seedlings in’Eureka’lemon self-crossed progenies.It is necessary to use more SSR primers or employ other technology more powerful molecular markers to complete the identification.If the zygotic self-crossed seedlings could be used for the evaluation of the resistance to canker disease,it is possible to well analyze the genetic background of citrus resistance,identify resistance genes,and provide resistant resources for disease resistance breeding of lemon.

关 键 词：'尤力克’柠檬 SSR分子标记 叶形态学观察 合子胚实生苗鉴定 抗性鉴定 

分 类 号：S436.66[农业科学—农业昆虫与害虫防治] S666.5[农业科学—植物保护]