Vol.12_No.2 - Pesticide Alternatives Lab - Michigan State University

Spring 2003 Resistant Pest Management Newsletter Vol. 12, No.2were evaluated in the F1 (Fig. 6).Association between Molecular Markers andResistance: The molecular data are being analyzedusing QTL packages (QTL cartographer Qgene) todetermine linkages between the markers and thephenotypic characterization. As preliminary analysis X2 at the 5% level was done using SAS. Putativeassociations were found between 43 SSRs markers andthe field phenotypic characterization (score 1.0 to 2.0of the levels of damage and populations).CONCLUSIONS and ONGOING WORKThe field evaluations in the family CM 8996 andtheir parental show the resistance of the genotypeMEcu-72 and the high susceptibility of theparental MCol-2246.Using SSR markers, putative association with theresistant lines was found. A linkage map is beingconstructed using the SSR data and the fieldphenotypic characterization.Based on going QTL analysis, the marker linked tothe resistant gene(s) will be used as part of largescale screening of breeding lines and to acceleratethe breeding cycle for whiteflies resistance. Finemapping of the genes involved will be carried as afirst step toward the cloning of the resistant genesand the study of their expression.ACKNOWLEDGEMENTS We acknowledge the valuablecontribution of Nelson Morante in the establishment ofplants in the field.The New Zealand ministry of foreign Affairs andTrade provided financial support for parts of theresearch carried out in this work.40