ISSR Analysis Of Genetic Diversity And In-Vitro Conservation Of Rhododendron Germplasm Resources In Fujian

In this study,15 accessions of Rhododendron germplasm resources were collected for in vitro conservation. The leaves of R. farrerae from Nine Seazan mountain were used as the explants for establishing the in vitro regeneration system. The plantlets from"erqiao"Rhododendro were applied as the conservation materials to investigate the restricting growth conservation method, which provided scientific basis for the Rhododendro and in-vitro preservation of compositae plants. 15 accessions of Rhododendro plants were conserved in vitro and analysed by ISSR technique for discussing genetic diversity. The main results were as follows:1. Establishment of the regeneration system of Rhododendron plantsThe stem segments from the"erqiao"Rhododendro from Nine Seazan mountainand its plantlets were used as materials to study the best conditions of the surface sterilization, Callus induction ,Induction in vitro shoot ,proliferation and rooting. The results showed that: the best method of surface sterilization was treated with 75% alcohol (20s) +0.1% of HgCl2 (4min) +sterile water (8 time) +0.1% of HgCl2 (4 min); the best Callus induction medium was the1/4MS medium supplemented with 1.0㎎/L TDZ and0.10㎎/L NAA ,Induction rate was 95.58%. the best Bud induction medium was the 1/4MS medium supplemented with 1.0㎎/L ZT and0.05㎎/L NAA ,Differentiation rate was 90.67%;the best proliferation medium was the 1/4MS medium supplemented with 1.5㎎/L ZT and 0.1㎎/L NAA, and the proliferation coefficient was 8.20;the best rooting medium was 1/2MS +1.0㎎ / L NAA+0.05㎎ / LIBA, the Rooting rate was 81.5%.2. Study on in vitro conservation of Rhododendron plantsThe plantlets of"erqiao"Rhododendro which had grown for 2 months were used as materials. The effects of different concentrations of sucrose, agar, B9, Different medium composition and light intensity on restricting growth conservation of plantlets were evaluated. As the results showed, 1/6MS media containing 50 g/L sucrose and 9.5g/L AGAR l was the optimal condition for conservation. The survival rate was up to 70.6% after preservation for 8 months.Adding B9 1.5㎎/L Greatly improve storage time after a much longer time he survival rate was up to 70.6% .However, light intensity did not affect the in vitro conservation of"erqiao"Rhododendro . Light intensity has no significant effeect. 3 .the main kinds heritage of Rhododendron in Fujian diversity ISSR analysisIn this experiment, the genetic diversity of 15 accessions of Rhododendro germplasm resources was assessed by using ISSR As results showed, 83 amplified bands were produced by 11 random primers .Augmentation between with six and eleven. Average producing with the augmentation 7.6 . The ratio of polymorphic bands reached to 82.0% with 68 polymorphic bands appeared, which illustrated that 15 accessions of Rhododendro germplasm resources had abundant polymorphism and rich genetic resources. According to the diversity of the amplified bands, a dendrogram was constructed to indicate their genetic relationships When similarity coefficient was 0.56, 15 accessions of Rhododendro germplasm resource could be separated into 5 groups, the firstgroup includles 1,3,4,5,2;the second group only includles 12;the third group only includles 6;the four group includles 7,10,11,13,14,15, the five group includles 8 and 9;When similarity coefficient was 0.59, all Rhododendron species were divided into 2 groups. Additional cultivated varieties and wild varieties of genetic distance is big.4. The flag mountain national forest park of fujian Rhododendro ovatum group ISSR analysisthe genetic diversity of two Rhododendro ovatum groups from flag mountain was assessed by usingISSR(Dongyang lake group and Meiyu tan waterfall group).The resulted demonstrated that according to the Nei 's index ,Two groups total genetic diversity Ht = 0.3901 ;Groups genetic diversity Ht=0.3902;The genetic diversityHs=0.3702;Genetic differentiation coefficient for Gst=0.1887,Namely population genetic variation between population genetic variation of 18.87% ,81.13% genetic variation within the group ,The population of genetic differentiation coefficient calculation between the gene flow Nm = 0.2627 the two Rhododendro ovatum had less connettion with each other in genetic information.