普通油茶染色体制片技术优化及核型分析  

Optimization of chromosome mounting technique and karyotype analysis of Camellia oleifera

作　　者：叶天文 李艳民 张健 龚倩颖 袁德义[1] 肖诗鑫[1] YE Tianwen;LI Yanmin;ZHANG Jian;GONG Qianying;YUAN Deyi;XIAO Shixin(Key Laboratory of Non-Wood Forest Product of Ministry of Education,Central South University of Forestry and Technology,Changsha 410004,China)

机构地区：[1]中南林业科技大学,经济林培育与保护教育部重点实验室,湖南长沙410004

出　　处：《南京林业大学学报（自然科学版）》2020年第5期93-99,共7页Journal of Nanjing Forestry University：Natural Sciences Edition

基　　金：国家重点研发计划(2018YFD1000603);国家自然科学基金项目(31500553);中南林业科技大学创新基金项目(CZ2017B411)。

摘　　要：【目的】染色体是种内品种变异的遗传物质基础,明确普通油茶主栽品种染色体倍性及核型特征,可为育种和栽培中品种配置提供依据。【方法】以普通油茶3个主栽品种(‘华硕’、‘华鑫’、‘华金’)的扦插苗和实生苗根尖为试材,对油茶染色体制片技术实验进行优化,对3个品种进行核型分析。【结果】①改良的去壁低渗火焰干燥法更适合普通油茶染色体制片,根尖以0.002 mol/L 8-羟基喹啉预处理5~6 h,1.75%纤维素酶和1.75%果胶酶酶解120 min,蒸馏水后低渗30 min,制片效果最佳。②3个品种扦插苗染色体数目均为2n=6x=90,为六倍体,而3个品种的实生苗染色体数目为90、87、85和75等。③对扦插苗根尖细胞中期分裂相进行核型分析可知,‘华硕’、‘华鑫’核型都为2A,‘华金’核型为2B,核型公式分别为2n=90=63m(3SAT)+27sm(‘华硕’)、2n=90=58m(SAT)+32sm(‘华鑫’)、2n=90=64m+26sm(SAT)(‘华金’),核型不对称系数分别是6173%(‘华硕’)、61.13%(‘华鑫’)、61.44%(‘华金’)。【结论】优化的去壁低渗火焰干燥法更适合于普通油茶染色体制片,‘华硕’、‘华鑫’、‘华金’均为六倍体,而其实生后代会发生倍性分离。本研究为进一步开展普通油茶的倍性与核型研究奠定了基础。【Objective】TheCamellia oleiferaAbel.has a wide distribution and a long cultivation history, but its ploidyhas always been controversial, and there is a lack of research on ploidy and karyotype.The chromosome is the geneticbasis of interspecies variation;the chromosomal ploidy and karyotype characteristics of the main varieties ofC.oleifera are defined, providing a basis for the production and cultivation of new varieties.The chromosome mounting technique ofC.oleiferais no longer suitable for current experimental requirements.This study aims to optimize the chromosomemounting technique ofC.oleifera, compare and analyze the chromosome numbers of cuttings and seedlings, and the kar-yotype of some main varieties ofC.oleifera.【Method】In this study, the root tips of cutting stecklings and seedlings ofthree main cultivars (‘ Huashuo’, ‘ Huajin’ and ‘ Huaxin’) were used as test materials.Firstly, the chromosomemounting technique was optimized by modifying key steps of the wall degradation hypotonic method, including pre-treat-ment, enzymatic hydrolysis and posterior hypotonicity.Secondly, to identify the material for a karyotype analysis, themodified wall degradation hypotonic method was used to unlock the chromosome number of the three main cultivars ofC.oleifera.Finally, the karyotype of the three cultivars ofC.oleiferawas unlocked, and the karyotype formula and pivotalkaryotype parameters were clarified.【Result】The following three points can be summarized from this study:(1) The optimized chromosome mounting technique, which included pre-treatment of the tender root tip with a solution of 0.002 mol/L 8-hydroxyquinoline for 5-6 hours, hypotonicity for 60 min in 0.075 mol/L KCl solution, enzymolyzation with amixture of 1.75% cellulase and 1.75% pectinase for 120 min at 20 ℃ in the dark, posterior hypotonicity in distilledwater, and finally fixing with fresh Carnoy solution for more than 30 min, was found to be the best for chromosomepreparation.The results showed that the modified wall degradat

关 键 词：普通油茶 染色体制片 染色体 倍性 核型 

分 类 号：S794.4[农业科学—林木遗传育种]