Potential Geographical Distributions And Clonal Structure Of The Clintonia Udensis Trautv. Et Mey

Clintonia udensis is a member of Clintonia(Liliaceae).As a perennial herbaceous plant,this species have two cytotypes which include diploid and tetraploid.In this study,the Max Ent model and Arc-GIS spatial analysis techniques were used to explore the potential geographic distribution of Clintonia udensis in contemporary(1950-2000)and 21 century.Based on the above analyses,the prominent environmental factors were picked out which have significant impacts on the distribution of Clintonia udensis.Then we observed the leaf microstructure characteristic by using scanning electron microscope(SEM),and analyzed the clonal diversity and clonal structure of Clintonia udensis based on SSR molecular markers.The main results as follows:(1)In contemporary(1950-2000),Clintonia udensis mainly distributed in the southwest and northeast regions of China.In addition,this species could also be found in the north and east of China.Base on our results,the highly suitable areas includes the southern of Jilin,southeastern of Liaoning,the border of Hebei and Liaoning,the border between Hubei and Chongqing,the central and eastern of Sichuan and Shaanxi border,and the central of Guizhou.There are six factors out from twenty environmental factors whichmainly influencing the distribution of Clintonia udensis:Isothermality(BIO2/BIO7)(*100)(25)with the contribution rate of21.57%,Mean Temperature of Wettest Quarter(21 ?)with the contribution rate of 7.06%,Precipitation of Wettest Month 200 mm with the contribution rate of 0.57%,Precipitation of Wettest Quarter(600 mm)with the contribution rate of 4.11%,Precipitation of Warmest Quarter(550 mm)with the contribution rate of 54.7%,Precipitation of Coldest Quarter(40 mm)with the contribution rate of 11.72%.The cumulative contribution rate of six environmental factors is 99.73%.Precipitation of Warmest Quarter(550mm),Precipitation of Coldest Quarter(40 mm)and Isothermality(BIO2/BIO7)(*100)(25)might be the dominate environmental factors.Due to the changes in the prominent environmental factors,the suitable distribution of Clintonia udensis presents a shrinking trend in the future.(2)The microstructure of leaves of Clintonia udensis between diploid and tetraploid populations are very similar by observing from SEM.Most epidermal cells on the top of leaves are basic of quadrilateral which array neatly along the radial direction.Anticlinal walls are straight-shaped.Irregular polygon epidermal cells on the top of leaves and shallow waveform anticlinal wall are only found in tetraploid population distributed in northern slope of Hualongshan(HLB)of Shaanxi province.Epidermal cells on the down of leaves are also relatively similar which shows elongated cylindrical.All of the anticlinal walls are straight-shaped.Diploid and tetraploid populations of leaves epidermal cells are distributed waxiness,which showing scattered small crumb,but the tetraploidpopulation distributed in HLB and the diploid population distributed in southern slope of Hualongshan(HLN)were higher than the diploid population distributed in Jinhoulin(JHL)and the tetraploid population distributed in Mulinzi(MLZ)obviously.Stomatas distribute epidermal cells on the down of leaves which array along reticulated.Stomatas consists of two crescent-shaped guard cells.The size and number of stomatas are different between diploid and tetraploid populations.The correlation analysis by combining environmental factors with microstructure of leaves shown that leaves microstructure affected by the Isothermality and rainfall obviously.(3)The clonal diversity and cloning structure of four populations in Shaanxi province and Hubei province by using SSR molecular markers shown that: diploid and tetraploid populations are all polyclonal populations,and none monoclonal populations were found.There is high clonal differentiation in two cytotypes.All the clonal structure of Clintonia udensis are “Guerilla”.152 Clintonia udensis samples of four populations have 117 genotypes,the average clones is 29.5 at the population level in both cytotypes.Moreover,the Simpson index(D)and genotype ratio(PD)of diploid populations are 0.978 and 0.846,respectively.In tetraploid populations,the Simpson index(D)and genotype ratio(PD)are0.961 and 0.708.Clonal diversity of diploid populations is slightly higher than the tetraploid populations.Simpson index(D)is 0.992 and genotype ratio(PD)is 0.700 at species level.There is no significant correlation between clonal diversity and environmental factors based on correlation analysis.In conclusion,multipleorigins of genotypes,facultative sexual reproduction and update the seedlings should be the sources for maintaining rich clonal diversity within the Clintonia udensis.