Construction Of Virus Vector Of Gene CsMAPK In Cucumber And Analysis Of Germplasm Resources Diversity In Catharanthus Roseus

The conserved cDNA domain of CsMAPK was obtained in cucumber (Cucumis sativus L.) by using degenerate primer and RACE. Bioinformatic analysis showed show that this conserved domains sequence with the MAPK gene of the other plants has high homology (> 80%), which with the Arabidopsis genes ATMPK20 highest homology (90%). The results show that we have been successfully obtained conserved domains of CsMAPK gene in cucumber. In addition, the homology evolutionary tree showed the sequence is conserved domain of CsMAPK gene in cucumber.Further, to verify the functions of sequence, we will construct tobacco mosaic virus expresstion vector based on the principle of virus-induced gene silencing pre-built, and set up the transient expression system for verifying the function of gene sequence.Because Catharanthus roseus has strong ornamental value, flowering period long, varieties diverse, will be used in 2010 Shanghai EXPO extensively. This research analyzes the genetic diversity of germplasm resources in Catharanthus roseus by molecular markers. It provides a reference for genetic breeding in Catharanthus roseus.Genetic relationships between forty varieties of Catharanthus roseus which are suitably cultivated in Shanghai were analyzed by ISSR (inter-simple sequence repeat) markers. Genetic diversity and similarity were analyzed in molecular level and the purpose of this study is further perfecting the evaluation of species resource in Catharanthus roseus. The result showed that a total of 115 bands based on 20 primers were detected, out of which 78 were polymorphic (67.8%). As analyzed by POPGENE32, the average value of effective number of alleles, Nei's gene diversity and Shannon's information index were 1.6384, 0.3735, 0.5546, respectively. As analyzed by NCSYS, the Nei's genetic similarity coefficient between cultivars ranged from 0.150 and 0.900, mean is 0.584. Clustering analysis showed that the 40 varieties of C. roseus could be distinctively classified into 7 groups. This is in accord with previous result made by morphological study. The study will provide a basis for Catharanthus roseus varieties identify and species protection, and supply a theoretical basis for determining the genetic relationship and crossbreeding of Catharanthus roseus germplasm resources.