QTL mapping of flower morphology, fruit-related traits, bacterial spot resistance, and leaf flecking in an intraspecific cross of pepper (Capsicum annuum Linn).

Date

4-2006

Degree

Bachelor of Science in Biology

College

College of Arts and Sciences (CAS)

Adviser/Committee Chair

Merlyn S. Mendioro

Abstract

A screen for polymorphic candidate markers was done using an intraspecific cross of pepper, Capsicum annuum: (between bacterial spot susceptible female sweet parent (Nacional AG-506) x a resistant male hot pepper parent (CNPH703)). A total of 20 tomato SSR primers amplified genes in the parental to initially screen for candidate markers in agarose gel electrophoresis. The 0439 Recombinant Inbred Lines showed polymorphism under the Polyacrylamide Gel Electrophoresis. Segregation of flower morphology traits (corolla diameter, style exertion, pistil length, number of anther, number of petals, anther color and petal color) in the recombinant inbreds was also determined. Using histograms, two traits, style exertion and pistil length as well as differential expression for bacterial spot resistance showed normal distribution. Observations were also made as to the leaf flecking phenomenon in the same pepper population. Additional traits like capsaicin, oil content, sugar content, fruit weight, and fruit length to width ratio were also considered. All data were analyzed with QTL Cartographer.A total of 91 markers, 12 linkage groups and 690.4 cM were used in this study. Thirty-five QTLs were found. Fifteen QTLs for flower morphology traits, nine for bacterial spot resistance QTLs, two for foliar flecking and ten for fruit QTLs were categorically found using the software QTL Cartographer. Majority of the QTLs were found in linkage groups LG10A, LGO3B and LG10C (8, 7 and 9 respectively). In chromosomes 2, 8 and 3, the number of QTL was five, five, and four respectively. Only one QTL was found in chromosome 2. Some QTL aggregations were supported by correlation analysis.

Language

English

Location

UPLB Main Library Special Collections Section (USCS)

Call Number

Thesis

Document Type

Thesis

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