Identification of SSR molecular markers associated with soybean resistance to bed bug complex

• Grant number: 05/00945-9
• Support type: Scholarships in Brazil - Scientific Initiation
• Effective date (Start): June 01, 2005
• Effective date (End): May 31, 2006
• Field of knowledge: Agronomical Sciences - Agronomy - Crop Science
• Principal researcher: José Baldin Pinheiro
• Grantee: Marcio Pais de Arruda
• Home Institution: Escola Superior de Agricultura Luiz de Queiroz (ESALQ). Universidade de São Paulo (USP). Piracicaba , SP, Brazil

Abstract

Several insects are considered important pests in soybean crops, among them, the stink bugs Piezodorus guildinii, Nezara viridula and Euschistus heros. In Brazil, a few breeding programs aim to improve plant resistance to insects. It is due to the difficulty in incorporating resistance genes, which are mainly found in agronomically unsuitable genotypes. The cultivar IAC-100 is the first commercial material with this characteristic incorporated. Thus, molecular markers are important tools to help locating the genes of interest. In the present work, our goal is to identify SSR markers associated with the characteristics defining resistance to the stink bug complex in soybean using a BSA (Bulked Segregant Analysis) strategy. The field performance of the F2 generation of the cross between IAC 100 (resistant) X MG/BR 46 CONQUISTA (susceptible) will be evaluated. The experimental design employed will be random blocks with four replicates. The experimental plot will be represented by 12 plants planted at 0.5 X 0.5 m spacing. In order to elaborate the bulks, DNA from plants with extreme phenotypes will be extracted and analyzed with 120 SSR markers. The co-segregation between the marker and the phenotype will be evaluated and estimates of the value of the recombination frequency between the SSR marker and the genetic locus controlling the resistance phenotype will be obtained.