Study Genetic Diversity Of Tobacco Germplasm With Morphological Markers And SSR Markers

In order to improve breeding efficiency and improve the varieties on purpose. The experiment studies 25 parts tobacco varieties as test materials with the morphological markers and SSR molecular markers to analyze the genetic diversity of the test materials and explore the correlation of each other.The main results of the experiment are as follows:1.To analyze the morphology euclidean distance of 25 parts of tobacco material with the method of morphological markers, of which the Euclidean distances of 23 parts of tested flue-cured tobacco are 0.638-6.006. When the Euclidean distance value is 25, two categories are significantly divided into I iand Ⅰ 2; when the Euclidean distance value is 20, all the flue-cured tobacco series (Ⅰ 2) can be further divided into two groups (Ⅱ1、Ⅱ2). The first group (Ⅱ1) includes 408,Longjiang935,82-3041,Zhongyan90,Longjiang911,ongyan98,Jiyan10,Val16,S peightG-28,P3,Zhongyan100,Jiyan9,Yunyan97,Zhongyanl 5,Coker 139 and CV87.The second group comprises the other 7 parts flue-cured tobacco varieties. Overall, the genetic distance of the tested tobacco varieties is close.2. In this experiment there are 10 pairs of stable amplification and polymorphous primers were screened from 92 pairs distributed in 24 linkage groups SSR labeled primers. The 10 pairs of primers amplified 48 bands and 39 polymorphic bands. The amplified ratio is up to 81%. There are nine bands in all varieties, which reveals the homology among the various tobacco germplasm, to some extent.3.To analyze genetic distance of the 25 parts of tobacco with the SSR-PCR molecular markers, the average of the genetic similarity coefficient of flue-cured tobacco is 0.907 that is between 0.579-0.997, which indicates there is high genetic similarity and close genetic relationship of flue-cured tobacco varieties. The genetic distance of the 2 parts of sun-cured material whose average is 0.505 is relatively far from the 23 parts of flue-cured tobacco varieties.The first group (Ⅱ1) whose genetic similarity coefficient ranged 0.954-0.997 including 12 varieties namely RG17, NC89, SpeightG80, Damaoliu, Coker319, V2, Longjiang851, Vl16, P3, Zhongyan100, SpeightG28, CV87. The genetic similarity coefficient of the second group (II2) was 0.993-0.748 including the other 11 parts of flue-cured tobacco varieties.4.The thesis makes a further explore to the SSR-PCR genetic distance and Euclidean distance morphology relevance and makes a correlation analysis to the SSR genetic distance and morphology Euclidean distance using SPSS software. The results showed that the correlation coefficient r= 0.335 which got high degree of correlation as positive relevant significantly.