| Summary: | 碩士 === 國立屏東科技大學 === 農園生產系所 === 100 === The great number of seeds in the fruit of guava makes seedlessness one of the important breeding objectives in the improvement of guava fruit characteristics. In order to understand the cause for guava seedlessness, a complete seedless line M4-2 and a seeded line M3 with similar genetic background were employed in this experiment to compare and observe the development and organization of their floral parts. The results showed that the shape of anthers in M4-2 is asymmetric and deformed. No microsporocyte division was observed inside its anther locules and the anther can not split to release pollen. The style of its pistil is curved or unable to elongate fully. The ovary of its 3-5 mm flower buds contains a lot of abnormal hollow ovules. No ovules in the ovary were observed on the day before flowering. Only a narrow space was left in the location of seed cavity inside the ovary one week after flowering. This line, therefore, was not able to complete normal pollination and fertilization and its seedlessness belongs to parthenocarpic type. In addition, the genetic similarity between M3 and M4-2 was found as high as 0.96 using RAPD analysis. It was also found that polymorphic bands distinguishing M3 and M4-2 can be generated by 4 primers. Furthermore, polymorphic bands distinguishing loci between M3 and M4-2 were generated by SSR marker analysis. Further study is necessary to determine whether there markers are associated with seedless trait.
|
|---|
