Combining Ability on Main Agronomic Traits and Genetic Clustering of Nine New Breeds of Sweet Corns

  Objective  Genetic backgrounds and combining abilities of 9 newly bred sweet corn inbred lines were studied.

  Method   The inbred lines included 5 white sweet corn female parents P1 (i.e., TS01-1, BS02-1, GS132, AS67 and SS1) and 4 sweet corn male parents P2 (i.e., Mintianxi 688, Mintianxi G73, Mintianxi 197 and X90-34). They were cross-bred into 20 two-tone crosses by a 5×4 incomplete diallel design. The combining ability on 10 traits including plant height, ear location, panicle length, ear girth, ear row count, grains per row, hundred-grain weight, kernel ratio, panicle weight with and without husk, of each hybrid was determined.

  Result  Based on the de-husk panicle weight, the general combining abilities of the white sweet corn inbred lines were in the order of AS67 > GS132 > TS01-1 > BS02-1 > SS1, and those of the yellow sweet corns Mintianxi 688 > X90-34 > Mintianxi G73 > Mintianxi 197. AS67×Mintianxi 688 exhibited the highest specific combining ability with the greatest actual yield among all. The genetic cluster analysis classified the 9 parents into yellow-and white-kernel groups.

  Conclusion   The yellow-kernel and white-kernel sweet corn inbred lines crossed between the 9 parents showed superior heterosis, and the classifications were consistent between the parents and the experimental design.