The Primary Studies On Inheritance Laws Of Main Ornamental Characters And Anther Culture Of Pansy (Viola×wittrockiana Gams)

Pansy (Viola×wittrockiana Gams) is an important ornamental plant used in the winter and early spring. However, the study on character inheritance laws and heterosis use of pansy is not systematical inland and oversea. In this study five inbred lines of pansy were selected as parents for crossing according to the Griffing diallel cross method 2. Firstly, the number of seeds per capsule and germinating rate of seeds were investigated on 5 self-pollinated progenies and 10 F₁s,and heterosis of main ornamental characters was also investigated on 10 F₁s; On the other hand, the studies on inheritance laws were carried out for 9 main ornamental characters. The factors affecting callus induction and differentiation from the anther, including the culture media and genotype, were also primarily studied. The main results were as following:1. Parent No. 15 was superior to other parents on the number of seeds per capsule after self-crossing, and No. 4 was inferior; seventy per cent F₁ had heterosis, and the number of seeds per capsule mainly depended on bearing capacity of female parent and compatibility of the two parents.2. Germinating rate of seeds was significantly different among 5 inbred lines ranging from 43% to 82%; High heterosis was observed in the germinating rate of ten F₁S. Furthermore, the germinating rate was not significantly different among seven of ten F₁s.3. According to the g.c.a, it was indicated that we shoud choose parents of No. 22 or No. 11 for breeding large flower size, and parents of No. 22 or No. 15 for more number of flowers; parents of No. 4 or No. 11, especially No. 4, were the best choice for smaller plant size. In a word, the g.c.a gave us a useful reference for choosing parents.4. Acording to the s.c.a, it was indicated that the largest flower size was obtained in No. 9×No. 4 among ten cross combinations, and the better combination was No. 22×No. 9; More number of flowers were observed in cross combinations of No. 22×No. 15, No. 22×No. 4 and No. 22×No. 9; If both the large flower size and lots of flowers were considered, the combination of No. 22×No. 9 was superior. All in all, the s.c.a was valuable to utilize heterosis for breeder.5. The results of heritability analysis indicated that the broad heritabilities (h²_B) of different traits varied from 27.31% to 63.83% with an average of 40.01%, and the narrow heritabilities (h²_N) varied from 0 to 48.94% with an average of 19.38%. Both h²_N and h²_B were high for flower size, so flower size could be effectively selected in the early generations. The selection for other traits could be delayed to later generations because of low h²_N and h²_B. 6. The anther culture results of pansy indicated that the 7% sucrose and 0.5mg/L proline were effective to induce higher anther response, and the lower concentration of proline was useful to improve callus state. There was significantly difference within genotypes for inducing callus from anther with the induction frequency ranging from 3.7% to 29.05%, and the genotype DZ⁴ had the best response with 29.05%. Furthermore, IAA and TDZ were neccessary for shoot regeneration.