Mapping of quantitative resistance loci from soybean to stink bug complex

Author(s)

Milene Möller

• Document type: Master's Dissertation
• Press: Piracicaba.
• Institution: Universidade de São Paulo (USP). Escola Superior de Agricultura Luiz de Queiroz (ESALA/BC)
• Defense date: 2010-07-07

Examining board members

José Baldin Pinheiro; Alexandre Siqueira Guedes Coêlho; Anete Pereira de Souza

• Advisor: José Baldin Pinheiro

Abstract

Cultivation soybean in major agricultural areas and successive planting in the same area significantly contribute to the increase in the incidence of insect pests on this crop, causing increasing damage to production. The seed-sucking stink bugs are considered to be one of the major pests of soybeans. In this study, 286 F2 plants obtained from crosses of IAC-100 and CD-215 were used to identify markers linked to resistance genes to these insects. The completely randomized design was adopted and ten agronomic traits and five traits related to insect resistance were analyzed. A genetic map was constructed based on AFLP and TRAP markers. From 14 AFLP combinations used a total of 643 marks were obtained, of which 67 (10.42%) were polymorphic, with an average of 4.79 polymorphic marks per combination. For the TRAP marker, 11 primers combinations fixed/arbitrary generated 230 marks, of which 31 (13.48%) were polymorphic, an average of 2.82 polymorphic marks per combination. Despite the lower number of polymorphic marks per combination, the percentage of polymorphism obtained with the TRAP marker (0.13) was higher than that for AFLP (0.10). Intermediate PIC values were found, with an average of 0.37 for both markers. The SNP markers presented not informative polymorphisms and were not used in the mapping. The linkage map consisted of 49 markers (35 AFLP and 14 TRAP), scattered across 12 linkage groups, totalizing 696 cM with an average distance of 17.93 cM between markers. QTLs mapping was conducted using two distinct approaches. The single marker analysis allowed the identification of three and six QTLs (LOD=2.5), considering the significance level at 5% and 10%, respectively. The composite interval mapping approach allowed the identification of 14 QTLs, concerning five characters, scattered across eight linkage groups. The proportion of the phenotypic variation explained by these QTLs ranged from 8.94% to 59.97%. (AU)

• FAPESP's process: 07/06257-2 - MAPPING OF QTLs ASSOCIATED WITH SOYBEAN RESISTANCE TO STINK BUGS COMPLEX USING AFLP, TRAP, NBS AND SNP MARKERS.
• Grantee: Milene Möller
• Support Opportunities: Scholarships in Brazil - Master