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本研究调查了一年生辣椒和中华辣椒种的DNA甲基化多样性。选取了24个一年生辣椒栽培种和6个中华辣椒栽培种作为研究对象,采用MSAP(methylation-sensitive amplification polymorphism)技术对其基因组CCGG位点的甲基化多样性进行了分析。结果表明,从63对MSAP引物中筛选出5对重复性好、条带清晰的引物对,对30份辣椒种质基因组DNA进行MSAP扩增,得到939条带谱,其中多态性条带937个,多态性比例高达99.79%。DNA甲基化模式分析表明,类型Ⅰ为非甲基化带型(3721),类型Ⅱ为半甲基化带型(3152),类型Ⅲ为全甲基化带型(3839),辣椒甲基化模式主要以全甲基化为主,一年生辣椒(Capsicum annuum L.)和中华辣椒(Capsicum chinense Jacquin)甲基化条带平均分别为319和217,其扩增位点的甲基化率分别77.24%和63.64%,差异达极显著水平。基于相似性系数的UPGMA法聚类分析,在0.68相似水平可以将30个种质分为3个类,第1类:No.10~No.13和No.15共5个种质,其中No.10为一年生辣椒,其它4个为中华辣椒;第2类:No.2~No.9、No.14、No.16~No.30,其中No.14和No.17为中华辣椒;第3类:只有No.1,为一年生辣椒。应用MSAP未能将一年生辣椒和中华辣椒区分开来,表明辣椒表观遗传十分丰富。Nei’s基因多态性指数(h)和Shannon信息指数(I)在2个栽培种中分别为0.204 0和0.329 8、0.186 4和0.297 5,一年生辣椒的表观遗传多样性稍高于中华辣椒。DNA甲基化多样性作为标志遗传多样性的一种信号源,本研究结果为深入探讨辣椒种群分化及物种进化奠定了基础。
This study investigated the DNA methylation diversity of annual and Chinese capsicum species. Twenty-four annual pepper cultivars and six Chinese capsicum cultivars were selected as research objects. The methylation-sensitive amplification polymorphism (MSAP) was used to analyze the methylation diversity of CCGG loci. The results showed that among 63 pairs of MSAP primers, 5 pairs of primer pairs with good repeatability and clear bands were screened and 939 bands were obtained from 30 capsicum genomic DNAs, of which 937 A, the proportion of polymorphisms up to 99.79%. DNA methylation pattern analysis showed that type Ⅰ was unmethylated (3721), type Ⅱ was semimethylated (3152), type Ⅲ was methylated (3839), and pepper was methyl The methylation patterns of Capsicum annuum L. and Capsicum chinense Jacquin were 319 and 217, respectively. The methylation rates of the amplified sites were 77.24% and 63.64% respectively, with the difference reaching a significant level. Based on the UPGMA clustering analysis based on the similarity coefficient, 30 germplasms could be divided into 3 groups at the 0.68 similarity level, and the first group was 5 germplasms of No.10 to No.13 and No.15, in which No .10 for the annual pepper, the other four for the Chinese pepper; Class 2: No.2 ~ No.9, No.14, No.16 ~ No.30, No.14 and No.17 for the Chinese pepper; 3 categories: only No. 1, annual peppers. The application of MSAP failed to distinguish perennial peppers from Chinese peppers, indicating that the pepper epigenetic is very rich. The Nei’s gene polymorphism index (h) and Shannon’s information index (I) were 0.204 0 and 0.329 8, 0.1886 4 and 0.297 5 in two cultivars respectively. The epigenetic diversity of annual peppers was slightly higher than that of Chinese peppers. DNA methylation diversity as a marker of genetic diversity as a signal source, the results of this study for in-depth study of pepper population differentiation and species evolution laid the foundation.