The recovery of recombinant inbreds outyielding the hybrid in tomato

Publications commenting on the possibility of fixing heterosis and the poss ibility to transgress heterosis through partition of crop yield into geneti c components have prompted us to reconsider our views on the relative impor tance of hybrid versus inbred vigour. The three genetic components of crop yield, all assessed in the absence of competition, are: (1) yield per plant assessed by the progeny mean, (2) tolerance to stresses assessed by the pr ogeny standardized mean, and (3) responsiveness to inputs assessed by the p rogeny standardized selection differential. Although fixation of heterosis using the top commercial tomato hybrids was based only on the first genetic component of crop yield and quality, inbreds outyielding the original hybr id were obtained relatively easily. The results indicated that selection fo r homozygote superiority on the basis of the three genetic components of cr op yield and quality, would lead to the development of tomato inbreds outpe rforming the hybrids.