Studies Of Heterosis And Genetic Characteristics Of Main Ornamental Traits In Dianthus Barbatus

Dianthus barbatus are cherished by people due to its elegant color, attractive flower shape and rich aroma. It can be planted as pot flower or cut flower with significant economic benefits. At present, the main cultivars of D. barbatus are heavily dependent on importation. However, the high price has become the main factor to limit its wide use.Accordingly, it has great significance for breeding new cut flower varieties of D. barbatus with independent intellectual property rights and suitable for cultivation in Guangdong area.The experiment was lay out to explore the heterosis and genetic effects of hybrids F1 in D.barbatus. It can be used as theoretical basis and practical guidance in the breeding of new varieties of D. barbatus.Six inbred lines verities were chosen as hybird parents to get 21 combinations by using diallel cross method 2. Afterward, analysis of hybrid advantages, combining ability,heritability and correlation was carried out; meanwhile to study the characters of color type and classification of quantitative raits. We used analytical hierarchy process and the grey relational analysis to establish the comprehensive evaluation system of cut D. barbatus.1. Heterosis analysis revealed that 75.96 % of hybrids F1 had mid-parent heterosis and53.37 % of hybrids F1 possessed high-parent heterosis. Nine traits such as plant height,plant width, effective tiller number, inflorescence diameter, inflorescence height, leaf length, leaf width, stem diameter and internode length generally showed over high-parent heterosis and mid-parent heterosis. The longevity of inflorescence and the inflorescence lower edge angle had mid-parent heterosis. The initial flowering time and blossom period showed over-low parent heterosis.2. The analysis of general combining ability indicate that inbred lines of E7 a, E11 andE23-31 are ideal parents with more excellent properties. Inbred line E7 a showed excellent performance in 11 aspect including plant height, plant width, stem diameter, etc. It is suitable for breeding new varieties with long branch, better stalk, strong tiller ability, large flower shape and early flowering. Inbred line E11 showed a better performance in florescence, plant width, inflorescence diameter, and as better parent line to be use in breeding new varieties with high stem, large flowers, early flowering time and long ornamental period. Inbred line E23-31 have good characters in florescence, effective tiller number and inflorescence lower edge angle and it is suitable for breeding new varieties with high yield and early flowering time. The analysis of special combining ability showed that the cross combination of E7 a E11, E23-31E11, E23-31E7 a, E7 a E6, E14E7 a,E23-31E14 and E7 a E23-30 possessed more characters in accordance with the breeding objectives of D. barbatus.3. The results of genetic analysis indicate that plant height, plant width, initial blooming time and blossom period, the longevity of inflorescence, inflorescence diameter,the inflorescence lower edge angle and the internode length are mainly controlled by the non-additive genes effect, and additive effect played an auxiliary role. It also showed that leaf width was mainly affected by the additive genes effects. Meanwhile, inflorescence height and leaf length were only influenced by the non-additive effects. The 13 main characters of cut D. barbatus were less influenced by environmental factors.4. As for F1 hybrids, RHS Colour Chart can accurately distinguish the difference of color between self lines and hybrid. CIELab color system combining with the design and color clustering analysis and ISCC-NBS color representation can get better results of classification of colours. The color brightness L* and a* and b* of different hybrids showed a significant negative correlation relationship. As the red and yellow degrees get higher, the brightness of the petals gets lower. According to the L*, a* and b* values of parents, we can select F1 hybrid oriented conforming to the requirements of new varieties.5. A comprehensive evaluation system of cut D. barbatus were established by means of Combining analytical hierarchy process and the grey relational analysis. The results ofheterosis and inheritance laws indicated that E23-31,E7 a,E11 and E14 were effective and excellent parents while hybrids F1(E7a E11,E7 a E6,E23-31E11,E23-31E7 a and E14E11)could confirm to the goal of breeding and have good potential.