Genetic Diversity And Genetic Analysis Of Several Main Characters In Seedling Stage Of Bitter Gourd(Momordica Charantia L.)

Bitter gourd(Momordica charantia L.)is an important vegetable in southern of China and its cultivation area is expanding year by year.Bitter gourd's.construction of genetic map,gene mapping and cloning are hard to obtain because of germplasm distribution,cultivation evolution and consumption habits restricted.Therefore,it is very significance to find polymorphism germplasm resources for bitter gourd genetic breeding and production.51 bitter materials from different countries and regions were used in this study.combined ISSR,SSR,SRAP molecular markers with morphological marker to study the genetic diversity of bitter germplasm.the amplification results of ISSR,SSR and SRAP molecular markers on 52 Momordica charantia germplasm accessions were analysed by NTSYS-pc2.10e,and the clustering dendrogram was formed by UPGMA method.materials 04-17 and 25 as parents,the major gene + more hybrid genetic model was used to analyses the inheritance of the Average-bud length,Growth rate,Chlorophyll content,Cotyledons length and Cotyledons width of seedling important properties.The main results showed that:(1)The results of investigation and analysis on the 31 morphological characters showed that there was great difference in all the phenotypic traits of 51 materials.The average coefficient of variation was 25.73%,of which the maximum coefficient of variation is bitterness(55.79%),and the minimum coefficient of variation is firmness(5.40%).Among 31 morphological characters,25 pairs of characters like beginning of flowering and the first female flower node had extremely significant positive correlation.21 pairs of characters such as fruit diameter,index of fruit shape and so on had extremely significant negative correlation,16 pairs of characters such as fruit firmness and pulp thickness had significant positive correlation,16 pairs of characters such as weight of single fruit and fruit length had significant negative correlation.In the principal component analysis,the cumulative contribution rate of 73.47%for the-previous.10.factors.Clustering analysis by flexible group average method showed that these 51 germplasm accessions were divided into 7 major groups at the genetic distance of 0.46,and the second group was subdivided into 17 subgroups at the threshold of 0.24.(2)According to primers screening,19 pairs polymorphism primers were chosen from 104 ISSR primers,13 pairs polymorphism primers were chosen from 200 SSR primers,and primers all comes from cucumber,Thus it can be concluded that bitter sibling species SSR primers in bitter materials shuttle ability was very poor,30 pairs polymorphism primers were chosen from 638 SRAP primers.There were 249 polymorphic fragments were amplified by three molecular markers,with polymorphic rate of 43.68%.The genetic similarity coefficient(GS)of 52 materials accessions were 0.4859?0.8112,and the average similarity coefficient was 0.6133.at the threshold of 0.63 where all the tested materials were divided into 6 major groups by ISSR.SSR and SRAP molecular markers.(3)Through compared the clustering results of 51 germplasm resources with 52 parts of molecular markers clustering results,it was founded that molecular markers.and morphological clustering results have certain similarities.In both classification methods,from Japan,Hainan and Guangzhou bitter melon germplasm are classified in the same category,which means that these materials have closed genetic relationships.(4)Genetic analysis of important characters in seedling stage results showed that the average buds length was controlled by two major genes with additive-dominance-epistatic genes;the.growth rate was controlled by one additive-dominant major genes plus additive-dominance-epistatic polygene;completely dominant gene controlled chlorophyll content's genetic;Cotyledons width's optional model,which controlled by negative completely dominant gene;Cotyledon length of bitter gourd was controlled by the additive-dominant gene,exist negative additive effect and dominant negative effect.The five traits genetic analysis showed that environmental conditions had great influence on characters genetic during bitter gourd seedling stage.