Complex genetics controls natural variation among seed quality phenotypes in a recombinant inbred population of an interspecific cross between Solanum lycopersicum×Solanum pimpinellifolium

Abstract

Seed quality in tomato is associated with many complex physiological and genetic traits. While plant processes are frequently controlled by the action of small- to large-effect genes that follow classic Mendelian inheritance, our study suggests that seed quality is primarily quantitative and genetically complex. Using a recombinant inbred line population of Solanum lycopersicum×Solanum pimpinellifolium, we identified quantitative trait loci (QTLs) influencing seed quality phenotypes under non-stress, as well as salt, osmotic, cold, high-temperature and oxidative stress conditions. In total, 42 seed quality traits were analysed and 120 QTLs were identified for germination traits under different conditions. Significant phenotypic correlations were observed between germination traits under optimal conditions, as well as under different stress conditions. In conclusion, one or more QTLs were identified for each trait with some of these QTLs co-locating. Co-location of QTLs for different traits can be an indication that a locus has pleiotropic effects on multiple traits due to a common mechanistic basis. However, several QTLs also dissected seed quality in its separate components, suggesting different physiological mechanisms and signalling pathways for different seed quality attributes. Seed quality is a complex trait which comprises a large number of physiological principles related to important plant developmental processes. We used a RIL population of Solanum lycopersicum (cv. Money maker)×Solanum pimpinellifolium to determine the genetic factors influencing the different aspects of seed quality in tomato. In total 42 seed quality traits were analyzed and one or more QTLs were identified for each trait with some of these QTLs co-locating. However, several QTLs also dissected seed quality in its separate components, suggesting different physiological mechanisms and signaling pathways for different seed quality attributes. © 2011 Blackwell Publishing Ltd.