The Study On Community Characteristics And Phylogenetic Based On Its Sequence Of Camellia Luteoflora Li Ex H.T.Chang

Camellia luteoflora Li ex H.T.Chang belongs to the Camellia,which is a rare and endangered plant in China.It has high research and ornamental value and is an important tea plant germplasm.Camellia luteoflora is shrubs or small trees,mainly distributed in Guizhou Province Chishui Alsophila spinulosa national nature reserve,and more growth in the altitude of 500 ~ 800 m cliff or stream.Because of its small quantity,narrow distribution,habitat and community associated species continue to change,so that the size and number of wild populations continue to decrease,so the protection of Camellia luteoflora is imminent.This paper is based on the study of the associated species,community characteristics,population structure,niche,biological characteristics and ITS sequences of the community of Camellia luteoflora.The aim of this paper is to understand the survival status of Camellia luteoflora population,the endangered mechanism,the system evolutionary status,suitable environment for the Camellia luteoflora scientific research,protection and management to provide theoretical and practical basis.The results are as follows:1 The results showed that there were 148 species of vascular plants in the surveyed plots,belonging to 71 families and 116 genera,and the flora of the community was more tropical than the temperate constituents.There were also significant differences in species diversity indices among different communities in different communities or in different habitats.Survival diversity of the whole species such as the five species diversity index are herbaceous layer> shrub layer> tree layer.2 Camellia luteoflora was mainly distributed in Phyllostachys pubescens forest,bamboo and broad-leaved mixed forest,evergreen and deciduous broad-leaved mixed forest and other three types of communities,the vertical structure of the community layer was divided into tree layer,shrub layer and herb layer.The spectral analysis showed that the high bud plants were dominant in the tree layer,shrub layer and herbaceous layer.The population structure of Camellia luteoflora was stable,the local area was in recession,and the survival status of seedling was worrying.3 The study on the phenological phenology,flowering dynamics,flower characteristics and seed characteristics of small yellow tea showed that the small yellow tea began to flowering in November,and the flowering period was about 4 months.Two rounds,the base together,seed round,the shape of the larger differences,the existence of embryo abortion,abortion of the seeds and smaller molds easy to mold,natural seed germination rate was low.Artificial seed breeding breeding in the shell when the crack is about to harvest,premature collection of seeds immature,too late collection of fruit shell cracking,seed scattered.4 The genetic length of ITS was about 610 bp,and the genetic distance of 7 populations was 0.021 and 0.051.The genetic distance between BPT and SGY was the smallest,and BPT and XTZ the largest.The clustering of Camellia luteoflora populations by using UPGMA method showed that there were no obvious geographical distributions in different groups of Camellia luteoflora.Construction of phylogenetic tree based on NJ and ML method for the ITS sequences of Camellia luteoflora and other Camelliaceae.The results are divided into two major branches,which were divided into two branches,Tutcheria kweichowensis Chang et Y.K.Li,Gordonia chrysandra Cowan,other Camellias was a branch.Schima argentea Pritz.ex Diels,Ternstroemia gymnanthera(Wight et Arn.)Beddome,Adinandra bockiana,Eurya loquaiana Dunn,Cleyera japonica Thunbw was another branch.It was supported by rate of 99% or more.Different species of Camellia group was gathered in a support rate of 99% or more,of which small Camellia luteoflora.and Camellia pubipetala Wan et Huang relationship was most closest,the support rate of 79%.Other groups of Theaceae did not form a clear branch,staggered branch.The reasons for the endangered Camellia luteoflora by comprehensive analysising might have the following points:1 Habitat changes to some extent had an impact on all species,Camellia luteoflora population was sall,habitat fragile,mostly in the valley on both sides or steep slopes,the same time,Combined with damp and gully habitat for bamboo growth,bamboo can influence it on the shade,mechanical damage,litter suppression,nutrient competition and allelopathy and other competitive ways to exclude Camellia luteoflora and other plants,so that Camellia luteoflora population affected by the environment would be more obvious.2 Camellia luteoflora flowering susceptible to environmental interference,there was the phenomenon of embryo abortion,smaller seeds easy to mildew,seed setting rate lowly.In addition,it was grown in steep slopes,valleys,rain and other habitat pressure,bamboo leaves werw not perishable and bamboo Canopy closure so that Camellia luteoflora was not easy to contact with soil germination,natural regeneration ability was poor,seedling growth for the pressure of young trees had been large.3 Artificial disturbance,especially bamboo artificial tending,exacerbated the fragmented distribution of Camellia luteoflora.and population decline.4 The genetic distance between the population was small,but the inbreeding recession may be a potential crisis of Camellia luteoflora.Thus,the protection measures and management of Camellia luteoflora mainly considered the following aspects:1 To strengthen the local protection,protection the original habitat,to strengthen the control of vine and bamboo around Camellia luteoflora plantation.Selecting the appropriate location to establish a special growth law,natural regeneration and other monitoring base and artificial breeding base for cultivation,which was useful for the collection of fine seeds and timely wild germplasm rejuvenation work.2 To carry out exsitu conservation,to establish new wild and semi-wild populations of Camellia luteoflora,and to expand the scale and quantity of the population by means of regression introduction plan,artificial introduction plan and enhancement plan.3 Based on the deep understanding of the reproductive characteristics,reproductive characteristics and genetic characteristics of the Camellia luteoflora,the appropriate human intervention to promoteed pollination,reduceed seed abortion,and timely treated the surface of the seed germination like bare stone,bamboo leaves,reducing seed mold4 Appropriate introduction of different natural Camellia luteoflora groups to promoted gene exchange among different populations,in order to avoid inbreeding recession,to ensure the genetic diversity of various populations.5 To strengthen the protection of propaganda work to improve the surrounding residents of the protection of endangered plants,control human interference and avoid felling and destruction.