Study On Phenotypic Genetic Diversity And Landscape Application Of Five Species Of Chamaenerion In Tibet

The germplasm resources of Chamaenerion in Tibet are most abundant.Chamaenerion are perennial herbs,which are ecologically restored medicinal ornamental plants.In order to carry out the identification,classification,resource protection,garden application and germplasm exchange of Chamaenerion,we investigated the resources of Chamaenerion in Tibet,analyzed the genetic diversity of phenotypic characters,and studied the application of garden cultivation.1.Resource survey4 species and 1 subspecies of Chamaenerion are distributed in Tibet,and all of them are distributed in Linzhi City.C.latifolium population with an area of less than 10 m~2was found only at an altitude of 4 100 m on the western slope of Shergyla Mountain.C.conspersum is widely distributed in 3 500 m～4 200 m vegetation destruction area in Linzhi City.The distribution areas of C.angustifolium and C.angustifolium subsp.circumvagum in Tibet do not overlap,and the habitat types are not the same.The C.speciosum is distributed in the cold and humid slope of3 700 m～4 700 m above sea level in the southern foothills of Himalayas.2.Study on genetic Diversity of Phenotype traitsThe interspecific variation is the main source of phenotypic variation,and its total morphological diversity index is 1.071,which shows abundant morphological diversity in 20 characters.The order of phenotypic stability was C.speciosum>C.latifolium>C.angustifolium>C.angustifolium subsp.circumvagumhairy>C.conspersum.According to the Q-type cluster,Chamaenerion distributed in Tibet was divided into two groups which had significant difference in morphology.One group was comprised by C.speciosum,C.latifolium and C.conspersum,while the other was comprised by C.angustifolium and C.angustifolium subsp.circumvagum.The 32 traits were divided into vegetative organ and reproductive organ group by R-type cluster,and some traits are correlation.The cumulative contribution rate of the first four principal components was 94.329%by principal component analysis,Phenotypic traits that play a decisive role are flower buds drooping or erect,whether the bracts and the blades are in the same shape,pistil length,number of lateral veins,bract length,inflorescence length,branching case,leaf with or without hairy,leaf-side vein clear or not,ratio of bract length to leaf length,number of pollen germination holes.These phenotypic traits basically reflect the main characteristics of the results of Q-type cluster classification.Bayes discrimination of quantitative traits proved that leaf width,Inflorescence length,pistil length and fruit stalk length had strong discriminating ability to the classification of the genus Chamaenerion.The discriminant formula can be used to manage the electronic database of Chamaenerion in the future.3.Cultivation Management and Garden ApplicationThe conditions of seed soaking in Chamaenerion are as follows:the germination rate of the C.angustifolium seeds soaked in warm water at50℃for 12 h was the best in the experiment.The seeds of C.angustifolium subsp.cirumvagum and C.speciosum were soaked in warm water at 40℃for 12 h,and the germination rate was the best.The germination rate of C.conspersum seeds soaked in 40℃warm water for 24 h was the best in the experiment.The photosynthetic characteristics of Chamaenerion are as follows:C.angustifolium,C.angustifolium subsp.circumvagum,C.latifolium have obvious photoinhibition phenomenon.However,C.conspersum is the most suitable for high light intensity in Tibet.It is necessary to shade C.angustifolium and C.Angustifolium subsp.circumvagum、C.latifolium under high light intensity in the cultivation process,while C.conspersum should be supplemented with light during the cultivation process.The modes of reproduction of the genus Chamaenerion are as follows:The genus of Chamaenerion are the beautify flowers which can be cultivated in the flower border、parterre、lawn or open space by seed reproduction,ramet reproduction,layering propagation,and also are pioneer herb of the water and soil conservation and ecological restoration of the side slope.