| The genus Lilium, established by Linnaeus in 1753, was widely distributed in the Northern Hemisphere. The disputes have never stopped since Endlicher earliest proposed the classification (taxonomy) of the infrageneric in 1836. Baker and Wilson, famous scholar, put forward views on the classification, which was not universally acknowledged. In 1949, Comber established the classification of the genus Lilium according to the morphological characteristics, which was accepted by most of the scholars up to now. But some researchers’late results according to systematic development were not identical with Comber’s, the main difference was the systematics position of L. dauricum, L. henryi and Sect. Sinomartagon. The great differentiation of Lilium occurred in China, where was one of the distribution center. Comprehensive molecular systematics of Lilium distributed in China has not been reported. It is necessary to study the phylogenetic relationship to solve the infrageneric of the genus Lilium, also urgent to utilize resources reasonable and develop flower culture industry.23 lily wild species and 2 varietyies were chosen for the present study, two molecular markers, sequence-related amplified polymorphism (SRAP) and amplified fragment length polymorphism (AFLP), were used to probe the infrageneric phylogenetic relationship and the classification of Lilium. The population genetic diversity and genetic structure of L. sargentiae were analyzed in view of rich resources in Chongqing, and resources utilization and protection were also proposed. The main results were as follows.1. The genus Lilium was rich in genetic diversity, the difference was significant on the level of species, genetic foundation was extensive23 lily wild species,2 varieties were chosen to probe the infrageneric phylogenetic relationship based on SRAP and AFLP. DNA extracted from 23 lily wild species was PCR amplified, and 19 SRAP primer combinations were used. A total of 236 clear DNA bands were amplified,233 of which were polymorphic, the proportion was 98.72% with average 12.3 polymorphic loci per SRAP primer combination. The genetic similarities ranged from 0.3750 to 0.7679. DNA extracted from 25 lily species was PCR amplified, using 8 AFLP primer combinations, a total of 395 clear DNA bands were amplified,368 of which were polymorphic, the average proportion was 93.12%, the similarity index ranged from 0.4417 to 0.8126. The two molecular markers showed that the genetic diversity was rich, the difference was significant on the level of species, and germplasm was rich in genus Lilium in China.2. Molecular systematics and morphological classification were partially identicalTwo phylogenetic trees were constructed based on two molecular markers. The results were partially consistent with morphology classification. The clustering of Sect. Martagon and Sect. Leucolirion was basically identical with morphology classification based on SRAP and AFLP. SRAP dendrogram showed that the germplasms of Sect. Martagon clustered together, Sect. Sinomartagon comprised a few clades, L. dauricum and L. lancifolium clustered together, separated with the germplasms of Sect. Lophophorum. AFLP dendrogram showed that the clustering results were mostly consistent with traditional taxonomy, four major clades including 25 species were delimited, the clustering results of Sect. Martagon and Sect. Leucolirion were mostly consistent with traditional taxonomy, whereas the clustering results of Sect. Sinomartagon and Sect. Lophophorum were different with traditional taxonomy. It demonstrated that it’s difficult to classify Lilium only based on the morphological characteristics, because phylogenetic relationship was distant despite that morphological characteristics were similar between some species such as L. henryi and L. rosthornii.3. The germplasms of Sect. Sinomartagon were complex, the differentiation was great in the sectionSect. Sinomartagon was characterized by no bell-shaped corolla, revolute tepals, open stamen. Using 11 wild species and 2 varieties of Sect. Sinomartagon as material, the morphological characteristics was analyzed, flower colour, fringed outgrowth on the petal base, leaf type, internode length and plant height were apparently different. SRAP dendrogram showed that 3 clades including 10 species were delimited under group III and IV except L. henryi. AFLP dendrogram also showed that 10 wild species and 2 varieties were divided into different clades under group II and III except L. henryi. Two molecular markers showed that Sect. Sinomartagon germplasms were not clustered into one group, but divided into different clades, it demonstrated that the differentiation occurred in Sect. Sinomartagon, the origin of Sect. Sinomartagon could be multielement.4. L. henryi and Sect. Leucolirion were the closely related systemsComber classified L. henryi and L. rosthornii into Sect. Sinomartagon according to the similarity of the morphological characteristics. In the present study two molecular markers showed that L. henryi was not clustered into Sect. Sinomartagon germplasms, but clustered one clade into Sect. Leucolirion. It suggested that L. henryi was closely related with Sect. Leucolirion, especially with L. regale subsection, and distantly related with Sect. Sinomartagon.5. Gene exchanges existed between Sect. Lophophorum and Sect. SinomartagonSect. Sinomartagon and Sect. Lophophorum were separate section in "Flora of China" because of the apparent difference of flower shape. The result showed that two sections germlpasms could not be divided separately by two molecular markers dendrogram, it suggested that gene exchanges existed between the two sections.6. L. tsingtauense and L. Distichum were the closely related systemsLeaves of L. tsingtauense and L. Distichum were whorled, flowers were spotted, both two phylogenetic trees showed that L. tsingtauense and L. Distichum were clustered into one group, it suggested that L. tsingtauense and L. Distichum were the closely related systems, which was identical with morphology classification.7. Systematics position of L. dauricum was controversialAlthough L. dauricum was classified into Sect. Daurolirion which comprised only one species by Comber, L. dauricum and L. concolor were classified into Sect. Lophophorum, because morphological characteristics of L. dauricum and L. concolor were similar in traditional taxonomy in China. The result showed that L. dauricum was not clustered into one group with L. amoenum and L. concolor of Sect. Lophophorumon the basis of SRAP dendrogram, L. dauricum was clustered into other germplasms on the basis of AFLP dendrogram, which proved that systematics position of L. dauricum is uncertain.8. L. sargentiae was rich in genetic diversity100 wild lily samples were collected from 10 populations, and 15 SRAP primer combinations were used for determination. The results showed that L. sargentiae was rich in genetic diversity on the level of populations and species of genus Lilium, the genetic diversity within populations exceeded other monocotyledonous plants, low coefficient of cross-pollination and asexual reproduction might be the main reason. High degree of variation of the population of L. sargentiae occurred, the variation within populations exceeded among populations, the restraint of gene flow, geography obstructs and small population were the main reason of genetic differentiation in L. sargentiae. |
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