Study On Genetic Diversity And Variation Of Casuarina Equisetifolia Provenance Population

Casuarina equisetifolia is the most important tree species in coastal protection plantation in southeastern and southern China. It plays an important role in improving ecological environment and promoting economic development. C. equisetifolia has a wide natural distribution in Australia, East-South Asia and the Pacific. It is one of the most extensively introduced tree species outside its natural range, especially into tropical/subtropical zones. Many provenances were developed in long system development and domestication, which provided plenty of original materials for breeding. The genetic diversity of C. equisetifolia and genetic variation were studied from phenotype, nutrient to gene by provenance trails and RAPD markers. Excellent provenances suitable to cultivate in South Fujian were selected at last. The main study results were as follows:1. The mean weight of 1000 seeds and germination rate differed greatly among different provenances. The differences in height and ground diameter of seedling and clonal seedlings among provenances were of significant level by variance analysis. The latitude, longitude and altitude of 41 provenances had significant effect on height growth of seedlings.2. At the age of eleven, four populations of C. equisetifolia grew differently. Natural populations from South-East Asia grew fastest and natural populations from Australia/Pacific grew slowest.There were significant differences among provenances all of the growth and morphological characteristics. These differences resulted from genetic factors. The variation among provenances tended to be stable at the age of four or five, so the early selection could start from four or five years. Different provenances had highly significant correlations in most of growth characteristics, the correlation between axis persistence and stem straightness was highly significant.3. The variation and characteristics of mineral elements in brachlets of 11-year-old provenances of C. equisetifolia were studied. The results indicated that contents of all measured elements among provenances varied significantly. The mean ash content was 4.18%.There were positive...