Innovation utilization of germplasm resources of self-fertile safflower buckwheat

【Objective】The genetic analysis of F₂ population of hybrid progenies of homo-flower white buckwheat and heteromorphous safflower buckwheat would provide a theoretical basis for resource innovation and new varieties of common buckwheat.【Method】Seven agronomic traits such as flower color, style type, flowering days, number of growing days, plant height were measured on the F₂ populations of hybrid progenies of homo-flower white buckwheat and short style safflower buckwheat, and carried out genetic diversity and principal component analysis.【Result】In the F₂ population, individual plants with white flowers accounted for 27.92%, pink flowers and light pink flowers accounted for 72.08%, indicating that safflower was not completely dominant to white flowers. In addition, the separation ratio of homotypes(equal styles) and heteromorphic flowers(short styles, long styles) was 2:1, and it could be inferred that the isome-tric styles were dominant heteromorphic styles. Among the 7 agronomic traits, the coefficients of variation of flowering days, growing days, main stem node number and stem diameter were 9.97%, 7.16%, 9.88% and 9.57%, respectively, which were less than 10.00%;the coefficients of variation of number of seeds per plant, plant height and number of first branch were 59.85%, 21.75% and 21.80%, respectively, which were all greater than 20.00%. The flowering days was significantly negatively correlated with plant height(P<0.05, the same below), and was significantly positively correlated with the number of first branch;the number of growing days were not significantly negatively correlated with plant height, number of the main stalk section, number of first branch and stem diameter(P>0.05, the same below). Among the four plant type-related traits, plant height was significantly positively correlated with the number of first branch, and extremely significantly positively correlated with the number of the main stalk section and stem diameter. As a yield trait, the number of seeds per plant was extremely negatively correlated with flowering days, was significantly negatively correlated with number of growing days, and was extremely significantly positively correlated with four plant type-related traits. The eigenvalues of the first two factors in the principal component analysis were greater than 1.000, and the cumulative contribution rate was 56.083%, which reflected the main information of the agronomic traits measured. The first common factor was mainly determined by four factors:plant height, number of the main stalk section, stem diameter and number of seeds per plant, and was called plant type factor;the second common factor had the largest load of flowering days, which was called reproductive factor. These two common factors both promoted and restricted each other. Super parental separation was found in all agronomic traits of F₂ population. Although no pink homo-flower individual plants were found, but 70 light pink homo-flower individual plants were observed. Eight of them were pink homo-flower individual plants which were earlier than their fathers and more productive than their mother.【Conclusion】The variations of flowering days, number of growing days, number of the main stalk section and stem diameter are small and stability is high, while the variation of number of seeds per plant, plant height and number of first branch of first order is high and stability is low. In the cross breeding of homo-flower white buckwheat and heteromorphous safflower buckwheat, the relationship between reproductive factors and plant type factors should be well coordinated, and the target selection should be carried out according to the correlation of each trait, so as to obtain safflower buckwheat with early maturity, high yield and stable yield.