Screening for introgressions contributing to tomato yellow leaf curl virus resistance in tomato, Lycopersicon esculentum mill.

Date

4-2006

Degree

Bachelor of Science in Biology

College

College of Arts and Sciences (CAS)

Adviser/Committee Chair

Celia B. Dela Viña

Abstract

MALABANAN, KATRINA B. 2006. Screening for Introgressions Contributing to Tomato Yellow Leaf Curl Virus Resistance in Tomato, Lycopersicon esculentum Mill.. University of the Philippines Los Banos. Bachelor of Science in Biology major in Genetics

Adviser: Prof. Celia B. dela Vina

ABSTRACT

Using 30 cleaved amplified polymorphic sequence (CAPS) and 16 simple sequence repeats (SSR) markers, six breeding lines of tomato (Lycopersicon esculentum Mill.) with accession numbers FLA505, FLA478, FLA496, FLA653, 99 SC, FAVI 10 were screened for "non-esculentum" introgressed regions which may contribute to Tomato Yellow Leaf Curl Virus (TYLCV) resistance. Six CAPS markers and four SSR markers, namely T0507, TG275, TG497, cLET24.12, cT129, cT239, SSR478, SSR92, SSR47, and SSR20 generated polymorphic bands. lntrogression regions were detected at chromosomes 1, 6, 11, and 12. CAPS marker cT239 was used to genotype the two F2 populations CLN2764-82 and CLN2779-24. Chi-square tests showed that both F2 populations followed the 1:2:1 expected segregation ratio if one gene pair controls the trait with the allele for resistance completely dominant to the allele for susceptibility. Four F2 populations namely: CLN2762-246, CLN2777-168, CLN2764-82 and CLN2779- 24, were planted in the open experimental field and phenotyped for symptoms of TYLCV infection. Plants with leaf yellowing, stunting, and leaf curling or any combination of two symptoms were classified as susceptible to TYLCV while those exhibiting stunting only or no symptom were classified as resistant to the virus. The observe phenotypes segregated 3 susceptible: 1 resistant which was opposite the expected 3 resistant: 1 susceptible ratio. This was probably because some tomato plants which may be genotypically TYLCV-resistant showed symptoms similar to TYLCV but might have been infected by other viruses present in the field.

Language

English

Location

UPLB Main Library Special Collections Section (USCS)

Call Number

Thesis

Document Type

Thesis

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