| Gerbera(Gerbera jamesonii Bolus) has become one of five cutting flowers in the world because of the annual flowering, beautiful color, huge flowers, rich flower types, straight peduncle and long vast life. The new varieties with high ornamental value and adaptation are needed by the rapidly developing floral market. Therefore, it’s significant to build an evaluation system and summarize the genetic laws, so as to provide a theoretical reference for the introduction and speed up the process of breeding new varieties. In this experiment,12 gerbera cultivars were observed to set up an evaluation model and the pollen germination ability was tested respectively. Moreover, some cross combinations were made to study the genetic variation of seven main ornamental traits. The main results are as follows:1. Flower color, flower diameter, floret type, peduncle length, peduncle diameter and vast life were selected as evaluation indicators and a scoring criteria was made by means of Delphi method and referring to relevant literature. Then the analytic hierarchy process was used to analyze each factor to determine the synthetic weight of each evaluation index. Based on scoring criteria and weights, the composite score of six ornamental traits of each variety was calculated.12 varieties were divided into three grades by using K-Means cluster analysis. Then the ornamental evaluation system of gerbera was built initially. The results showed that:the most important ornamental traits was flower color, whose weight was 0.360. The second one was double flower trait, whose weight was 0.198. The weights reduced sequentially in vase life, inflorescence diameter, peduncle length and peduncle diameter. Six varieties were assigned to the first class, five varieties to the second class and one to the third class. The occupation ratio was 50%,42% and 8%, respectively.2. Field experiments were carried out to investigate eight major production traits of 12 varieties of gerbera. And a production evaluation system of gerbera was initially established through the same way. The results indicated that winter yield, annual yield and autumn yield had the most important effect, and the weight was 0.278,0.176 and 0.107 respectively. Four varieties were assigned to the first class, seven varieties to the second class and one to the third class. The occupation ratio was 33%,58% and 9%, respectively.3. A synthetic system was established for gerbera, and 13 factors affecting the quality of gerbera were analyzed. The results indicated that flower color, winter yield and vase life had the most important effect, and the weight was 0.180,0.139 and 0.111, respectively. Six varieties were assigned to the first class, three varieties to the second class and three to the third class. The occupation ratio was 50%,25% and 25%, respectively.4. In order to provide a scientific basis for the selection of male parent, the method of germination in vitro was applied to judge the pollen germination ability. In this study, ME3+200g·L-1PEG4000 was used as the culture medium to compare pollen germination of all varieties. It turned out that each species appeared some long slender and flexuous pollen tubes. The pollen germination rate ranged from 14.61% to 67.86%, and it was significantly different between varieties. The pollen germination of 12 Gerbera varieties in sequence from high to low was:S109(67.86%), S187(65.52%), S145(63.75%), S300(51.67%), S75(49.03%), S62(48.19%), S87(47.06%), S103(38.40%), S47(35.00%), S123(24.19%), 149(15.38%) and S46(14.61%).5. Twelve hybridized combinations were made with 12 gerbera varieties. Then the 7 ornamental characteristics of hybrids were statistical analyzed, they are flower color, flower diameter, disc diameter, floret type, flower posture, peduncle length and peduncle diameter. The study showed that colors were widely separated in F1 generation. The heritability of purple red was higher than that of red, and that of red was greater than that of orange. Yellow exhibited matroclinal inheritance but not orange, red, purple red or white. The frequency of bicolor in hybrids was significantly higher in the combination with white female parent. The heritability of semi-double was stronger than that of single or double, and same level shape was stronger than below or above in flower form. The flower diameter and peduncle length of F1 generation were both depressed to a certain extent. The mean flower diameter and peduncle length of F1 hybrids were 98.4% and 82.1% of that of parents respectively. The disc diameter/flower diameter of hybrids was larger than the mean value of their parents obviously. The mean ratio of F1 was 136.3% of that of parents. The peduncle diameter of hybrids was similar to the mean value of that of parents and the mean peduncle diameter of F1 was 100.4% of that of parents. In total, seven major traits of gerbera were widely separated in F1 hybrids, a large number of transgressive plants still exhibited because of high coefficient of variation, and these genetic laws were extremely significant to new variety breeding. |
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