Studies On Salt-tolerant Mechanism And Genetic Diversity In Lilium Ssp.

In order to investigate the morphological and physio-biochemical changes under salt stress in Lilium ssp. Series concentration of salt were used to treat the Sorbonne and Prato. The results indicated that height of Sorbonne and Prato was inhibited to grow slowly, diameter of stem decreased. Net photosynthesis rate and transpiration rate decreased as a whole. The activities of POD and CAT increased under the low concentration of salinity, then decreased, changes of soluble protein content was not identical with proline content under higher concentration of salinity. But, in contrast to Prato, leaves number of Sorbonne was nearly unchanged, chlorophyll content decreased in a fairly extent, activity of POD increased, and activity of CAT decreased more quickly. MDA content was higher than control. In addition, activity of POD changed abruptly during the growing time.The changes of these parameters inferred that Prato was more salt-tolerance than Sorbonne at the later stage.The cytological development of leaves of salt-tolerance species prato and combined salt-sensitive species sorobnne in lilium, stressed with different concentration of salinity, was studied using transmission electron microscopy. The results indicated that under the control and low NaCl concentration, leaves of the prato species were abundant with organelles, the lamellae were lined regularly, with the increase of salinity concentration, the number of organelles decreased, the chloroplasts degenerated. In contrast to prato, leaves of sorobnne showed abnormal behaviors under low NaCl concentration, including degenerated organelles, vacuolated chloroplasts and the loosened lamellae. In addition, mitochondria began to degenerate prior to chloroplasts.It is inferred that degeneration of chloroplasts contributed to the ultra structure of degeneration of mitochondria, which further leading to senescence of leaves.Sixty wild species and cultivars of Lilium ssp. were analyzed by fluorescent AFLP. Six primer pairs generate 120 bands which showed polymorphism, with an average of 20 polymorphic bands per primer pair. It showed that AFLP is a powerful tool for distinguishing the genetic diversity of Lilium ssp.. The averagee expected heterozygousity of AFLP loci among all accessions was 0.824, the heterozygousity among wild species was higher than that among cultivars. The result of UPGMA showed that the evolutional relationship between wild species and their cultivars were intimate, and genetic stocks could be divided into two groups. The first group included Longiflorum×Asiatic hybrids, wild species, Asiatic hybrids, Trumpet hybrids, Oriental X Trumpet hybrids, which was also classified into two subgroups; the second group was the clustering of L .speciosum, Longiflorum hybrids and Oriental hybrids, in addition, Oriental hybrids could also be divided into two small groups.Under the analysis of the dosages of primary ingredients in the system of RAPD, RAPD amplified system for Lilium ssp was founded, at the same time, by using 22 primers to analyze the geneticdiversity and relationship of sixty lily species, reached the same result of AFLP by UPGMA.