Identification of Quantitative Trait Loci Conferring Resistance to Bemisia tabaci in an F2 Population of Solanum lycopersicum × Solanum habrochaites Accession LA1777

Abstract

Solanum habrochaites S. Knapp and D.M. Spooner accession LA1777 have reported resistance to the sweetpotato whitefly (SPWF), Bemisia tabaci (Genn.). An interspecific F2 population of 171 plants between tomato [Solanum lycopersicum L. (formerly Lycopersicon esculentum Mill.)] and LA1777 was bioassayed against adult SPWF in a greenhouse using clip cages. A selective genotyping analysis was used with 11 resistant and 10 susceptible plants to locate resistance genes by testing them with molecular markers spanning most of the tomato genome at about 10-cM intervals. Markers in four regions were found to be associated with resistance, where three of them showed significantly strong associations and one showed a weak association through chi-square and analyses of variance. However, through quantitative trait locus (QTL) analysis using molecular markers, all four regions were identified as major QTLs with logarithm of odds (LOD) values of 4.87 to 5.95. The four QTLs were identified near the markers TG313 on chromosome 10, C2_At2g41680 on chromosome 9, TG523/T0408 on chromosome 11, and TG400/cLEG-37-G17 on chromosome 11. Multiple regression analysis produced similar results as above with fixed effects of single loci as well as interaction among some of the QTLs.