| This experiment was conducted in horticulture station of Shandong Agricultural University, used 24 cultivars collected by breeding office of horticulture department of SDAU, we classified these germplasm and conducted genetic analysis on main quantitative characters of these cultivars. Results indicated: According to quantitative classification of cauliflower germplasm, cauliflower cultivars can be divided into two groups: early maturing group and later maturing group. Characteristic character, maturation period, which can discriminate these two groups, was selected from step discrimination. Cluster analysis of cauliflower germplasm indicated: cauliflower cultivars can be divided into three ecotypes, reduction rate of leaf number between autumn seeding and spring seeding (RRLN) characteristic character dividing these three groups, was selected from step discrimination. Three groups are: (1) Low temperature inactivity ecotype, had low RRLN, which was 0.216. Lowest values of reduction rate of weight per curd flower between autumn sowing and spring sowing (RRWC) was 0.468. Curd flower can develop normally when sowed in spring, this indicated that they had certain tolerance to low temperature. but they all matured latterly. (2) Low temperature middle sensitive ecotype: RRLN was relatively high, was 0.407. Lowest values of RRWC was 0.937 respectively. They could develop curd flower with certain weight, but weight per curd flower was much lower than that of cultivars of first ecotype.(3) Low temperature sensitive ecotype: RRLN was highest, was 0.7538. Lowest values of RRWC was 0.983 respectively. Systemic classification and ecotype classification of cauliflower cultivars resources were related with each other. Which was reflected in the alternative proceeding of shape mutation and ecotype differentiation. Heritability values of index of plant shape, weight per curd were 14%, 26% during autumn breeding and 70%, 93ï¼… during spring breeding. Indicated that heritance of these characters was influenced greatly by different environment. Heritability values of index of plant shape, number of total leaves and days from curd appearing to harvest were 32%,32%, 87%,95%, 88%,98%. Indicated that heritance of these three characters was influenced less by different environment. Broad heritability of index of plant shape was low both during autumn breeding and during spring breeding. Broad heritability of index of leaves shape, number of total leaves and the yield of biology was 70%,60%,62% during autumn breeding, and 43%,92%,93% during spring breeding.Coefficient of genetic variance of plant range, leaf width, stem diameter, area of total leaves, the yield of biology were 0.59,0.58,0.48,1.60,1.48,1.25 during autumn breeding, and 2.92,3.22,2.72,6.36,6.26,6.22 during spring breeding. Rate of Coefficient of genetic variance between spring breeding and autumn breeding was much larger than 4.0. Indicated that different expression of these characters was influenced by ecotype conditions between spring and autumn, and variance width of these characters was relatively rich between spring breeding and autumn breeding, especially during spring breeding, the new variances were got. Coefficient of genetic variance index of plant shape, number of total leaves and index of leaf shape were 0.35,0.59,0.40 during autumn breeding, and 0.53,1.01,0.43 during spring breeding. Rate of Coefficient of genetic variance between spring breeding and autumn breeding was less than 2.0, indicated that different expression of these characters was not almost influenced by different environment. Plant width, number of total, leaf width, days from curd appearing to harvest, stem diameter, area of total leaves and the yield of biology correlatedwith weight per curd at 0.001 level between spring breeding and autumn breeding. Index of curd shape correlated with weight per curd, and the coefficient of correlation were 0.882. Path analysis indicated that immediacy path coefficient of leaf width, days from c... |
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