Dissertation > Excellent graduate degree dissertation topics show

Development and Application of EST-SST Marker in Pepper

Author: LiJingJing
Tutor: WangShuBin
School: Nanjing Agricultural College
Course: Olericulture
Keywords: Pepper Eggplant EST-SSR Cytoplasmic male sterility (CMS) Genetic diversity Transferability
CLC: S641.3
Type: Master's thesis
Year: 2009
Downloads: 29
Quote: 0
Read: Download Dissertation

Abstract

EST (Expressed sequence tag) is the 5’or 3’ends of partial cDNA obtained from the sequencing of the clone which is selected from the cDNA bank. Because it could reflect the transcribed portion of the genome, the allele gene controlling the significant genotype could be identified directly. If be used in the genetic diversity identification, it will reflect the diversity of related gene in the population. Because of the conservation in EST flanking sequence, it has higher transferability in species or genus than non-coding sequence. The application of EST database in vegetable especially in pepper is relatively weak. Though some SSR markers had been added into the pepper (capsicum) molecular linkage map, only a few could be used as the public resource.EST had been used in functional genome research in many crops, but no report about male sterility. Nowadays, the markers related with pepper male sterility include RAPD, AFLP, SSR, without EST-SSR marker published. In this research,119 simple sequence repeats (SSR) were obtained by screening 4000 EST sequences of pepper, and 35 primers were designed. Against genomic DNA of cytoplasmic male sterility (CMS) line and maintainer line the EST-SSR markers were screened. Three polymorphic primer pairs Pe21, Pe26, Pe27 were first got with the amplification segments CMSPe2160, CMSPe26250, CMSPe273oo, respectively. Because EST has special characteristics of high conservation in coding DNA sequence, its application will accelerate the research in pepper male sterility mechanism.Vegetable Institute in Jiangsu Academy of Agricultural Science recently got some pepper materials. The problem about how about the relationship between the introduced and formal resource, must be found out before the utilization. In this study,10 EST-SSR markers were used in the genetic relationship identification of 47 capsicum germplasms(32 lab germplasms,15 introduced germplasms).70% of the primers showed polymorphic with 1645 different bands, which accounted for 77.8%. The number of alleles per primer ranged from 1 to 9, with the average of 4.5. Based on the UPMGA method, the accessions were classified into 6 groups with the coefficient indext at 0.732. The genetic relationship of accessions tested was revealed. The results provide valuable evidence for the classification, conservation and utilization of the Capsicum germplasm.Pepper EST-SSRs were tested in eggplants for transferability. Seven primers which could generate distinct bands in pepper genetic diversity study were amplified in 8 eggplant varieties. Six primers produced distinct bands, amounting for 85.7% in the 8 pepper primers.36 bands were amplified and 5.1 bands for each primer. It was founded that 26 bands were polymorphic, which occupied 72.2% among the bands. The accessions were classified into 3 groups based on the UPMGA method with the coefficient index at 0.654. The results proved that pepper EST-SSR had high transferability to eggplant and thus they can be used in eggplant molecular marker and comparative genome study in Solanaceae. Developing a suite of molecular marker between pepper and eggplant was testified feasible, which will not only save the primer cost, make the species comparative research, but also realize the evolution of genes in different species, and consequently find out the genome structure and function.

Related Dissertations

CLC: > Agricultural Sciences > Gardening > Vegetable gardening > Solanaceous > Chili
© 2012 www.DissertationTopic.Net Mobile