文摘
Heterotic response for total yield amongfive cultivar-groups of summer squash,Cocozelle, Vegetable Marrow, Zucchini,Crookneck and Straightneck, was studied intwo sets of diallel crosses evaluated intwo harvest seasons. Each diallel crossincluded two representatives of each thefive cultivar-groups. Griffing and diallelGGE biplot (genotype main effect andinteraction) analyses were carried out. Therelative importance of the specificcombining ability variance on totalvariance was greater than that reportedearlier for intragroup crosses. Highlysignificant heterosis was manifested onlyin combinations of Crooknecks orStraightnecks crossed to Cocozelles,Vegetable Marrows or Zucchinis. GGE biplotsshowed a consistent arrangement wheretesters of ssp. texana interactedwith cultivars of ssp. pepo and viceversa. We propose that the heteroticpattern of texana-pepo crosses couldbe potentially used to achieve increasedyields in hybrids by introgressing onegroup into another in a manner that wouldmaintain fruit attributes of thecultivar-group.
