Research On The Phenotype Diversity And Fruit Characteristics Of Chimonanthus Praecox In Zhejiang Province

Chimonanthus praecox is a deciduous shrub of Calycanthaceae,Chimonanthus genus which is native to China.It has beautiful forms,color and flower fragrance in winter,besides,which plays a very important role in urban landscape materials.The Chimonanthus praecox population of Zhejiang province is the only distribution point in eastern China,which is facing serious loss.Therefore,it is necessary to study the habitat,resource status and penotypic diversity of the germplasm resources for rational protection and introduction.To determine the resource status,morphlolgical variation,propagation and photosynthetic characteristic of seedling,wild population of Chimonanthus praecox in Zhejiang province were chosen as research subjects.Results were obtained as follows:The population structure of wild Chimonanthus praecox in zhejiang province is stable.Chimonanthus praecox was the dominant components of the shrub layer.The germplasm resources of the community has many characteristic.The middle-perianth of the flower are golden yellow,long-lanceolate,the tip of a sharp,invlute edge.The color of inner-perianth change from light red to puce,with a pinstripe or flaky distribution.There is rich variation of flowers and fruits.Zhejiang populations florescence is the late,has a small amount of persistent fruits.The flower enter into flowering time in mid-January,the period of peak flowering is from early February to early March,mid-March is the peak of period the flowers fall off,the fruits ripen in early July.The results of phenotypic diversity showed that there were rich variation and diversity of nineteen phenotypic traits of wild Chimonanthus praecox in Zhejiang province.The traits had extremely significant differences except for inner-perianth number and pistil length.The mean coefficient of variation of all traits was 17.58% with range from 7.30% to 45.23%.the average phenotypic differentiation coefficient was 40.36% with the range from 0.11% to 89.62%,phenotypic variation within a population was 55.62%.The variation within populations was greater than that among populations,which indicated that the former was the main source of the floral morphological variation.Correlation analysis showed that there was highly significant correlations among traits include corolla diameter,corolla inner diameter,flower cylinder depth,middle-perianth length,stamen number,fruit length,fruit wight,number of seeds,seed length and leaf length.The gray rational degree is largest between the p H of soil and the traits related to the length of flowers,fruits and leaves.The 1000-seed weight of the seeds of wild Chimonanthus praecox of Zhejiang Province was about 396.98 g,the viability was about 91 %.The exist of dense and hard seed coat and germination inhibitor make the highest seed germination rate was less than the seed lots viability and also influence the germination uniformity.Seed of soaking after pricked can improve the seed structure and in favor of germination.There were a few seedlings in will population of Chimonanthus praecox in Zhejiang province,the influences of soil drought stress on photosynthetic characteristics of Chimonanthus praecox leaves were studied by the test of potted 1-years-old Chimonanthus praecox seedlings.The results showed that: the content of chlorophyll and carotenoid decreased with the decreasing soil water content.Under the moderate stress,the net photosynthetic rate,the transpiration rate,stomatal conductance decreased significantly.Remarkable decreases of intercellular CO2 concentration under mild and moderate stress.The present conclusion is that the phtosynthesis of Chimonanthus praecox exhibits a certaind daptability to drought stress except severe stress.