Submitted to: Plant and Animal Genome Conference Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: 10/15/2006
Publication Date: 1/13/2007
Citation: Nimmakayala, P., Jeong, J., Rao, A.S., Levi, A., Reddy, U. 2007. Molecular Characterization of Citrullus Species and Subspecies Based on SSR and AFLP Analysis for Developing Interspecific Mapping Population. Plant and Animal Genome XV Conference. pp 132. Interpretive Summary:
Technical Abstract: Low genetic diversity exists in cultivated watermelon (Citrullus lanatus var. lanatus). The collection of watermelon U.S. Plant Introductions at the USDA, ARS, Plant Genetic Resources Conservation Unit (Griffin, Georgia) offers a great potential for genetic improvement of watermelon cultivars. Various breeding efforts have been focused on fruit characteristics like fruit size, maturity, rind color and sugar content, and disease resistance. The wild watermelons of African origin (Citrullus lanatus var. citroides) are resistant to diseases such as Fusarium wilt and Zucchini mosaic virus and also have a high percentage of female flowering. However, there is no sufficient information about genetic diversity at molecular level. In the present study, forty eight Simple Sequence Repeat (SSR) markers and 14 AFLP primer combinations were used to detect polymorphism among 32 U.S. Plant Introductions (PIs) collected from diverse geographical locations and representing major groups of Citrullus species (Supplied by Plant Genetic Resources Conservation Unit, Griffin, Georgia, US). AFLP markers showed high polymorphism (3098 polymorphic bands) and the SSR markers produced 294 polymorphisms among the watermelon germplasm collections. Genetic relationships and diversity estimates among and within the watermelon species will be presented. Crossing among Citrullus lanatus var. lanatus and Citrullus lanatus var. citroides germplasm lines is in progress.