Researches On Genetic Diversity And Fruit Characters Of Early-maturing Camellia Oleifera In Macheng

Camellia oleifera,belongs to Camellia genus in Theoideae family,is an important woody edible oil plants in China.In this paper,in order to provide scientific basis for the protection and utilization of the early-maturing Camellia oleifera resources in Macheng,Hubei province,fruit and leaf samples were collected from 50 trees in 3 early-maturing Camellia oleifera populations there,and researches were carried out on evalution of these germplasm resources based on molecular genetic diversity and fruit charaters data.Main results were as follows:（1）Optimized ISSR-PCR reaction system was established:2×Utaq PCR Master Mix10μL,template DNA 3μL,primer 0.6μL（10μmol/L）,add dd H₂O up to 20μL.（2）15 ISSR primers were screened out of 100 ISSR primers.Then ISSR-PCR amplification to the leaf genomic DNA of 50 sample trees was carried out.A total of 129clear loci were amplified,in which 122 were polymorphic loci and the percentage of polymorphic loci reached 95.31%.（3）Early-maturing Camellia oleifera in Macheng had a high level of genetic diversity.Its Nei’s gene diversity（He）was 0.3028,the Shannon’s information index（I）was 0.4605,the number of observed alleles（Na）was 1.9531,the number of effective alleles（Ne）was 1.5067 and the percentage of polymorphic loci（PPL）was 95.31%.Among three populations,Shuangmiaoguan population exhibited the highest diversity with the highest percentage of polymorphic loci,Nei’s genetic diversity and Shannon’s information index.（4）The genetic distances among three populations ranged from 0.0372 to 0.0998,the genetic identity among the three populations ranged from 0.9050 to 0.9635.The genetic identity among the 50 sample trees ranged from 0.64 to 0.88.Cluster dendrogram of the50 sample trees was drawed base on genetic identity and according to which these sample trees could be divided into 6 groups at genetic identity 0.69.（5）The mature period of the early-maturing Camellia oleifera in Macheng was from mid-September to early-October and it was very precious early-maturing germplasm resources;there were four kinds of fruit shape,the order from more to less was sphere-shape>ovoid-shape>olivary-shape>orange-shape;there were four kinds of fruits colors,i.e.cyan,red,yellowish red and greenish red,in which mixed color was the main fruit color and the fruits of greenish red were the most.（6）The oil content of kernel ranged from 17.83%to 54.39%,with an average value of 42.08%.In the three populations,the average kernel oil content of Youzhajie population was the highest（42.16%）and its coefficient of variation of kernel oil content was also the highest（36.56%）;the average kernel oil content of Fengboshan population was the lowest（41.98%）.（7）The coefficient of variation（CV）of 12 quantitative characters of the fruits ranged from 12.21%to 42.19%.There were 7 characters with CV≧20%,and 5characters with 10%≦CV<20%.The CV of seeds per fruit was the highest and the CV of fruit shape index was the lowest.The diversity index of 12 quantitative characters ranged from 1.339 to 1.866.The diversity index of fruit shape was the highest,while that of dry kernel rate was the lowest.There existed no much differences in the diversity index of the 12 quantitative characters among the populations,the diversity index of Fengboshan population,Shuangmiaoguan population and Youzhajie population was 1.594,1.558 and 1.477 respectively.In conclusion,according to above comprehensive analysis of the research results of molecular genetic diversity and fruit characters,the early-maturing Camellia oleifera germplasm resources in Macheng were rich in genetic diversity and were worthy of further researches and utilization.