| Chinese narcissus(Narcissus tazetta var.chinensis)has been a favorite ornamental plant in China. The plant blooms but has no seeds, so it only reproduces by vegetative propagation. To date,the varieties of Chinese narcissus are exiguous, and degenerate with age due to asexual reproduction. It is also difficult to improve and breed new varieties by traditional methods. In this paper, we assessed the genetic diversity of Chinese narcissus resources, investigated the mechanism of its sterility at cytological, physiological and molecular levels. Anther culture technique of Chinese narcissus was also developed in order to contribute its conservation and breeding. The results were as following.1. Random amplified polymorphic DNA (RAPD) and inter-simple sequence repeat (ISSR) methods were applied to detect the genetic variation of six cultivars of Chinese narcissus. Genetic variability within and among four individually sampled populations was also assessed using ISSR-PCR. For the cultivars, 33 RAPD and 16 ISSR primers generated 278 and 163 bands, of which 29.5% and 38% were polymorphic respectively. For four populations,16 ISSR primers were screened , a total of 155 bands were amplified. At specific level,the percentage of polymorphic bands was 40%,expected heterozygosity(h) and Shannons's information index(I) were 0.1276 and 0.1914 respectively. At the population level, the percentage of polymorphic bands was from 14.84% to 30.48%, expected heterozygosity(h) and Shannons's information index(I) were 0.0754 and 0.1119. 41% genetic variance was among populations and 59% genetic variance was among individuals within populations. Among four populations, the variance of the population in Zhangzhou was more abundant, and the variance of the population in Chongming was the lowest. All of these results indicated the level of genetic diversity of Chinese narcissus was relatively low. New methods for the development and conservation of Chinese narcissus were...
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