Analysis On Combining Ability And Effects Of Selection Of Crossing Combinations Of Poly-spike And Multispikelet

In the past decades of years,the yield of wheat is at the stage of slow increasing in all over the world.The primary causes are that the genetic basis and diversity betweenvarieties were little by little,the shortages and disadvantages of breeding approach of increasing ear quantity and improving the structure of plant type were serious increasingly while gaining achievement of increase of yield.Through long-term research, the mid-spikecultivars by the combining between poly-spike cultivars and big-spike cultivars got more and more attentions,but there have not found a appropriate approach by which to breed the perfect mid-spike cultivars.For breaking the restrictive barrier of wheat yield and achieveing the effectual combination between poly-spike cultivars and big-spike cultivars,the research chose six cultivars which were different in maturing dates,resistance and flexibility, zoology flexibility, yield characters and relationship of parentage to design crosses using 6×6 diallel crosses.And by the analized the combining ability and the influencing factors of yield (differentiation of spikelet,growing characteristics,HI,the plant height component), the research got several conclusions.1. Henong2552 was the better-breeding parent with early mature traits and eximous general traits.I₄ was the better-breeding parent with poly-spike traits and eximous general traits.Lankao906 and 95(156) were the big-spike better-breeding parents with multispikelet traits.Henong2552×Lankao906, I4×95(156), I4×Lankao906 were the important combinations for super breeding.2. The chosen parents should be super high-yielding cultivars and well circadian base. First,the poly-spike parents were with well flexibility traits and growing characteristics which were propitious to produce super high-yield.Second,they were with better coordination of the population stems and between leaves and stems.Third,they were with well circadian base of photosynthesis which was propitious to produce super high-yield. The big-spike parents were with multispikelet traits and well flexibility traits which were propitious to improve spike traits of the poly-spike parents.3.There were significant different on maturing dates and yield characters of reciprocal cross F1 hybrids.Especially when choosing the parents whose superior traits were complemented to each other, there was significant different on reciprocal cross F1 hybrids.Female parents were the poly-spike cultivars with early mature traits and well flexibility traits; male parents were the big-spike cultivars with multispikelet traits and well flexibility traits.In this research, Henong2552 and I4 were suitable for female parents; Lankao906 and 95(156) were suitable for male parents.These crosses were propitious to be polymerized traits of parents.