Study On The Genetic Diversity And Utilization Of The Germplasm Resource Of Lilium Pumilum Dc.

Lilium pumilum DC, also known as lilium tenuifolium, is perennial herbs belonging to Lilium sp. in Liliaceae. With a special taxonomic and many superior characteristics,L. pumilum is an important genetic resource for lily breeding and breed improvement. There are abundant germplasm resources of native L. pumilum in China. It has important significance for protection and innovation of germplasm resources, and lily breeding, which was collection of resources, studying on genetic variation of population under the ecological factor, such as different geographical location, ecological environment and climate condition, and finding out the adverse resistance. The germplasm resources of native L. pumilum were researched systematically in morphology, palynology, chromosme Karyotype, molecular marker, adversity resistance, and the crossbreeding were carried out preliminarily. The main results were as follows:1. By introduction and cultivation of Lilium pumilum, the differences within populations were greater than that among twenty five L. pumilum populations, the differences were mainly in the morphological characters, including hair of flower bud, leaf wideth, plant height, flower color, etc. There were significant or very significant correlation between the characters of leaf wideth, anther wideth, flower diameter and the geographical factors (longitude, latitude, elevation). The correlation analysis showed that character variations would be the result of joint action of heredity and environment. The pollen morphology were observed with the scanning electron microscope, the results showed that the pollen grain of L. pumilum was single, nearly elliptic in shape, with one germination groove on its surface. Variability coefficient of pollen traits within populations was greater than that among populations.2. Karyotype analysis revealed the diversity among populations. Every populations of L. pumilum were diploid, with basic chromosome number 12. In root tip cells, Chromosome numbers was mostly 2n=2x=24, In addition, there were aneuploid somatic cells attached 1-3 accessory chromosome. Chromosome types of L. pumilum included st, sm, t, m and T. The ratio of the longest chromosome/the shortest chromosome was from 1.73 to 5.90, mostly in the range from 2 to 4; asymmetry coefficient was between 75.6% and 89.6%; By karyotype analysis, six types could be divided:3B,4B,3A,4A,3C,4C, and 3B was the most type, which was 56%.3. SSR analysis showed 93.5% polymorphic loci percentage of intra-species was obtained from 25 lily populations using 12 pairs of primers. Ratio of polymorphic bands among populations ranged from 78.55% to 91.92%, with the average being 82.36%, which indicated that native populations had rich genetic diversity revealed by EST-SSR molecular marker. The results were in good agreement with those determined from morphology, pollen and karyotype. Based on number of allele (A), number of effective alleles(Ae), ShannonWiener's diversity index(I),observed heterozygosity(Ho), and expected heterozygosity (He), it draws the following conclusions:among twenty five populations, the genetic diversity of BSS populations was the highest, while XT populations was the lowest.4. Researches in adversity resistance of L. pumilum indicated that:Different population of L. pumilum has different anti-Fusarium oxysporum capacities, among the 25 populations, the most resistant populations in Tangshan and Gansu, and the weakest populations are Ningxia and Liaoning. L. pumilum could endure short-term low temperature -30℃; Under the higher temperature37℃, L. pumilum grow well, and could endure short-term high temperature 40℃; L. pumilum grow well in the soil of salt content lower than 0.3%, while they would be injured in the soil of salt content highter than 0.3%; L. pumilum was suitable for planting at shade degree from 30% to 60%.5. The best medium for pollen culture of L. pumilum was suerose5% and H3BO3 10%. Pollen germination rate of L. pumilum was still 50.5% at -20℃for 120d. By regular pollination, the higher cross compatibility of combinations was L. pumilum×'seberia'. It could improve fruit setting ratio by delaying pollination, cut-style pollination, and application of NAA to the combinations between and 'seberia','White Heaven','Elite'.As a result, L. pumilum was widely distributed in the provinces of North China. There was abundant genetic variation on morphology, pollen, karyotype and DNA molecular level within and between the species, so as an valuable resource for lily breeding, L. pumilum has special significance in lily cross breeding in China.