| Six inbred lines[003-87(P1), 003-24(P2), 003-10(P3), 003-81(P4), 003-36(P5),003-29(P6)] of head cabbage(Brassica oleracea.var.capitata), were selected to use asmaterials of the study. They were all bred by Horticultural Research Institute in ShanghaiAcademy of Agricultural Sciences. Using the design of complete diallel genetic cross, thestudy analyzed genetic parameters such as the combining ability, the heritability, the geneticvariation and the genetic correlation of fifteen quality characters such as the content ofvitamin C(V_c), reducing sugar, water and coarse fiber as well as the fresh edible flavor oftotal twenty-one materials.Results oft he study indicate:1. With a bigger variance of GCA than that of SCA, eleven characters in cabbage, i.e.the fresh-food flavor, the cooked-food flavor, the comprehensive flavor, the content ofwater, V_c and coarse fiber, the plant height, the number of outer leaves, the expansiondegree, petiole/leaf weight ratio and central column/head height ratio, were mainlyinherited by additive genes. The order for the narrow inheritability of eleven characters was:the comprehensive flavor＞the fresh edible flavor＞the cooked edible flavor＞the watercontent＞the V_c content＞the plant height＞the number of outer leaves＞the expansiondegree＞petiole/leaf weight ratio＞central column/head height ratio＞the content of coarsefiber. The narrow inheritability had a big influence on the variation of these eight characterswhile unadditive interaction and environment had a smaller influence on them, indicatingthey can be consolidated by family breeding. It can be obviously effective to select them inthe early generation. But petiole/leaf weight ratio, central column/head height ratio and thecontent of coarse fiber had a relatively low inheritability, hence making it better to selectthem in the late generation.2. The correlation of V_c and reducing sugar, the single-head weight and the coarsefiber, V_c and petiole/leaf weight ratio, the fresh-food flavor and petiole/leaf weight ratio, thefresh-food flavor and the density degree, the fresh-food flavor and central column/head height ratio, etc, are not positively or negatively significant. As indicated, the screening ofthese characters can carry out independently, i.e. the screening for one character of theseones didn't have a influence on other characters, leading to varieties with lots of excellentcharacters. However, the phenotype correlation and the genetic correlation of the V_c contentand the weight of single head, the V_c content and the flavor as well as among fresh-foodflavor, cooked-food flavor and comprehensive flavor reached a significant level, so thescreening for one character of these ones can produce a influence on the other characters.Furthermore, as shown by the additive analysis and the dominant analysis, the additivecorrelation of the water content and the fresh edible flavor as well as the water content andthe cooked edible flavor are extremely significant while the dominant correlation of themare not significant, which indicated that indirectly screening these characters in the earlygeneration can obtain good effects.3. The GCA of fotir characters, i.e. the V_c content, the. fresh-food flavor, the cooked--food flavor and the comprehensive flavor in the parent P6 is the highest among six inbredlines. Apart from the negative effect in two characters, the weight of single head and thedensity degree, P6 had more excellent characters, the combining ability ranking the secondor the third and more better quality characters of its cross progenies. Therefore, P6 can beconsidered as a suitable parent to pair the combination with excellent flavor and qualities.
|
PDF Full Text Request