Genetic Effects Of Ae.kotschyi Cytoplasm On Main Traits Of Wheat (Tritivum Aestivum L.)

Ae.kotschyi cytoplasm is one of the main types of male sterile cytoplasm in the research of hybrid wheat, and it is very useful to study its genetic effects. In this paper, three male sterile lines and their corresponding preserved lines, five restoring lines and their cross combinations were used to study effects of Ae.kotschyi cytoplasm on main agronomic and quality traits and their heterosis, and the differences of combining ability and genetic model were also compared between the two backgrounds of Ae.kotschyi cytoplasm and T. aestivum cytoplasm. The results were as follows:1) Ae.kotschyi cytoplasm had some effects on agronomic traits of common wheat, but the effects were different with different traits. Its effects were mainly that: the plant was shorten, and the 1000-grain weight, the spikelet weight and the spikelet number per culm decreased. However, the effects were different for the hybrids with different male sterile lines. Compared with the male sterile lines Yumai No.9 and S43, the effects for the hybrids with Yumai No.3 were unapparent on agronomic traits. Ae.kotschyi cytoplasm had a good effect on quality traits. Protein content and wet gluten content increased at the 1% significant level. By analysis of SDS polyacrylamide gel electrophoresis, differences between male-sterile lines and their corresponding maintainer had been found in gliadins of seeds. The result showed that the content of 41KD,39KD and 35KD polypeptides in K-type sterile lines was much higher than that in their corresponding maintainer lines, but no significant differences had been found between hybrids with Ae.kotschyi cytoplasm and T. aestivum cytoplasm. 2) Ae.kotschyi cytoplasm could affected heterosis over mid-parent and over high parent. Effects on heterosis over mid-parent and over high parent were obvious for maximum tillers, sterile spikelet number, wet glutin content, protein content, ear number per plant and grain number per culm ear. Under the background of Ae.kotschyi cytoplasm, the heterosis over mid-parent and over high parent of maximum tillers, ear number per plant and grain number per culm ear decreased greatly, and that of sterile spikelet number, wet glutin content and protein content increased.3) Ae.kotschyi cytoplasm had some effects on general combining ability(GCA) of parents and special combining ability(SCA) of hybrids. GCA of K-type sterile lines was lower than that of their corresponding maintainers in plant height, ear number per plant, maximum tillers and flag leaf width, but the opposite results could also be found in other traits such as ear length of main stem, heading date, flowering date and flag leaf length. SCA variance was mainly influenced by nucleus-cytoplasm interaction and its effects were different with different traits. There were different effects on SCA of different combinations for agronomic traits. The effects on SCA of most combinations were negative in plant height, ear number per plant, flag leaf width, ear length and maximum tillers, and were positive in flag leaf length.4) Differences of genetic model between the two backgrounds of Ae.kotschyi cytoplasm and T. aestivum cytoplasm could be found for some traits. The genetic models in the two types of cytoplasm were different for plant height, heading date and ear length per culm, but were similar for ear number per plant, maximum tillers, flag leaf length and width, and flowering date, the first of which did not fit additive-dominance model and others fitted. However, for the 4 characters which fitted additive-dominance model, the comparative results between the two backgrounds indicated that the number of dominant or recessive genes which controlled the expression of every character was different obviously in at least one parent. The degree of dominance, the dominant direction and the mean dominant degree were different between the backgrounds of Ae.kotschyi and T. aestivum cytoplasm.