| In order to know the species, resource conditions, genetic relationship andcomprehensive value of wild genetic resource of Rhododendron in Qin-ba Mountain, we hadcarried out four times for the exploration on the wild Rhododendron species, distribution,morphological characters, habitat conditions and resources feature in the this areas from April,2011to April,2013. And we had researched genetic relationship and comprehensive value ofRhododendron in this areas using Q cluster analysis and analytic hierarchy process. Theresults are following.1In the natural distribution area of Qin-ba Mountain, twenty species (R. capitatum, R.concinnum, R. purdomii, R. clementinae, R. detersile, R. hypoglaucum, R. sutchuenense, R.mariesii, R. hunnewellianum, R. maculiferum, R. augustinii, R. tsinlingense, R. stamineum, R.fargesii, R. mucronulatum, R. calophytum, R. recurvum, R. micranthum, R. argyrophyllum, R.simsii), eight subgroups (Subsection Micrantha, Subsection Lapponica, Subsection Triflora,Subsection Farrerae, Subsection Taliensia, Subsection Maculifera, Subsection Fortunea,Subsection Argyrophylla), five groups (Section Rhododendron, Section Brachycalyx, SectionTsutsusi, Section Choniastrum, Section Ponticum) and four subgenus (SubgenusHymenanthes, Subgenus Azaleastru, Subgenus Rhododendron, Subgenus Tsutsusi) had beenfound here.2In horizontal distribution, four species (R. clementinae, R. maculiferum, R. recurvum, R.detersile) were only found in north slope of Qinling, nine species (R. sutchuenens, R.augustinii, R. hypoglaucum, R. mariesii, R. fargesii, R. argyrophyllum, R. simsii, R.stamineum, R. hunnewellianum) were only found in south slope of Qinling and seven species(R. capitatum, R. purdomii, R. calophytum, R. tsiningense, R. mucronulatum, R. mcranthum, R.concinnum) were found in both slopes. In distribution of each specie, R. concinnumdistributed the most widely and was found in fourteen counties, R. purdomii was the secondwidely, found in nine counties, R. detersile, R. stamineum, R. fargesii and R. recurvumdistributed in smallest area and were found only in one county. There were the more than six species in Ningshan, Taibai, Langao and Pingli County, and only one specie in Kangxian,Zhenba, Zhenping and Hu xian County. In vertical distribution, wild Rhododendron aredistributed at the elevation of760to3700m. Fourteen species distribute at the elevation of1400to2800m.4species(R. mariesii, R. stamineum, R. micranthum and R. simsii) aregrown at the relatively lower elevation from700to1400m, and another2species (R.capitatum and R. detersile) at higher elevation from2800to3700m.3The community composition of Rhododendron changes along with the elevationchanges. In the highest elevation, the community is abundant, the accompanying plant speciesare the most. In the higher, the community is simple, with the Rhododendron is the dominantspecies. In the lowest, the community is composed of Rhododendron, broadleaveddeciduous forest and grass. The habitat of Rhododendron is in the slope, mountaitop, cliff,bush fallow, forest and near to brook. Its accompanying plant species are songshan category,birch and bambusoideae. The Rhododendron mainly distributed sporadically and flakily. Thewild genus Rhododendron has abundant morphological variation on the plant type, flowerorgan and leaf.4The euclidean distance of the twenty species of Rhododendron is from0.63to24.33,and they could divide into four groups at the thresholds of12.66. The first group contains R.purdomii,R. clementinae, R. hunnewellianum, R. hypoglaucum, R. maculiferum, R. augustinii,R. tsinlingense, R. fargesii and R. argyrophyllum. The second group contains R. capitatum, R.concinnum, R. detersile, R. mariesii, R. stamineum, R. mucronulatum and R. simsii. The thirdgroup contains R. calophytumand R. sutchuenense. The forth group contains R. recurvum and R. micranthum.5In the comprehensive value, R. concinnum got the highest marks and had the mostcomprehensive value. The second and third were R. calophytum and R. purdomii. R.micranthum had the least comprehensive value. According to the scores, the twenty specieswere divided into three levels. The first level had the most value, containing R. concinnum, R.calophytum, R. purdomii, R. sutchuenense and R. simsii. The second level had better value,containing R. capitatum, R. clementinae, R. detersile, R. hypoglaucum, R. mariesii, R.maculiferum, R. tsinlingense, R. stamineum and R. mucronulatum. The third level had the lessvalue, containing R. hunnewellianum, R. augustinii, R. fargesii, R. recurvum, R. micranthumand R. argyrophyllum. 6In the introduction and breedong, survival rate of introduction of Rhododendronreached or exceed60%, R. simsii got the highest survival rate, the second was R. concinnumand the lowest was R. sutchuenense. The research of cutting propagation on Rhododendron,using different concentrations of different hormoons and different culture substrata, indicatedthat ABT-6of100mg/L had the best results of cutting with the highest rooting percentage,and culture substrat of turf and vermiculite ratio of1:1had the best results of cutting with thehighest rooting percentage. |
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