Study On Heterosis And Heredity Of Quantitative Characters In Balsam Pear

Ten self-lines of balsam pear were divided into two groups, 5 female parents(W-001,W-002,W-003,W-004,W-005), 5 male parents(A-001,A-002,A-003,A-004,A-005), and 25 crosses were made by NC-â…¡. 25 crosses of 12 quantitative characters were analyzed according to analysis of variance, analysis of combining ability and analysis of genetic ability. 10 self-lines and 25 crosses were analyzed according to the key components analysis, heterosis analysis and grey correlative degree analysis of 12 quantitative characters. All the above were based on SAS software and DPS software and the data was completed on computer. The main results were concluded as follows:1. The analysis of heterosis indicates that the heterosis of quantitative characters of balsam pear is quite extensive. Fruit width has strongly positive heterosis as well as fruit firmness, soluble solid content and organic acid content. internode length shows negative heterosis, and other seven quantitative characters have the same level between positive heterosis and negative one. Heterosis degree of different characters is different. The heterosis of fruit width is the most evident one of all. The standard deviation of different crosses is different.2. 10 materials were made into 25 crosses of which 12 quantitative characters were analyzed according to analysis of variance. The result is variance is not so obvious between groups but quite clear between crosses.3. There is great difference among various characters on general combining ability, and so is variance of specific combining ability. We can comprehensively evaluate parents according to general combining ability and specific combining ability variances. Parent- A-002 is an ideal parent for its good characters. Parent- W-001 is an ideal parent to valuate quality characters.4. For the 12 characters investigated, the order of broad sense heritability is soluble solid content >fruit firmness >fruit length >dry matter > vitamin C >fruit shape index >number of fruit per plant >organic acid content >flesh thickness >internode length > fruit weight >fruit width. The order of narrow sense heritability is soluble solid content >number of fruit per plant>internode length> vitamin C>fruit length>dry matter>fruit weight >fruit shape index>fruit firmness>organic acid content>fruit width>flesh thickness. 5. On the key components analysis of 10 self-lines and their 25 crosses, the percentage of cumulative for the 6 bigger eigenvalue is 94.4%. On these characters, number of fruit per plant, fruit shape index and fruit firmness should be selected firstly. Then flesh thickness and internode length should be chosen and finally fruit length and vitamin C.6. On the grey correlative degree analysis of 10 self-lines and their 25 crosses, the results show that number of fruit per plant is closely related to fruit firmness and flesh thickness. Soluble solid content is closely related to fruit width, fruit weight and then fruit firmness. Flesh thickness is closely related to fruit firmness. Vitamin C is closely related to fruit length and then fruit width, fruit weight.