Conservation Biology Of Rhododendron Hainanense

Rhododendron hainanense is native to China,which only distributed around the mountain stream from 200?700 meters above sea level in Hainan and Guangxi Province.Rhododendron hainanense has high ornamental value and the ecological function of riverbank stabilization.It is a wild flower resource with great potential for development and application in Hainan.At present,due to the expansion of human activities,wild resources are being excavated,and the habitat of wild Rhododendron hainanense was destroyed due to the construction of large-scale water conservancy projects,and its population size is shrinking.This project provide a scientific basis for the protection of the wild Rhododendron hainanense resources and its development and utilization in Hainan Province,through the research of the distribution of Rhododendron hainanense in riparian zone,population dynamics and artificial reproduction technology.The main results are as follows:(1)Rhododendron hainanense distributed obviously more on winding bends than straight bends.Rhododendron hainanense on convex bank was at rising stage,which on concave bank was declining stage.Rhododendron hainanense was at rising stage both on upstream and downstream of convex bank,but lack of individual of different age-class on concave bank.The farther distance from the top of bend or river bank,the less individuals of each age-class distributed.(2)At 2×2m scale,the individuals showed an aggregation distribution on convex bank and its downstream,but a random distribution on its upstream.The individuals shown a random distribution on concave bank:and on both its upstream and downstream.The fast flow and steep slope may be the main reason for the fewer individuals and declining population on concave bank.(3)Gibberellin could effectively improve the germination rate and germination potential of Rhododendron hainanense's seeds,and the germination rate was up to 76.33%after soaking the seeds with 400 mg/L GA3 for 24 hours.The germination rate and germination potential were highest in pH 6.5.(4)The IBA could effectively improve Rhododendron hainanense's cuttings rooting rate.The rooting rate was up to 90.0%after soaking the cuttings with 600 mg/L IBA for 600s in substrate 2,and the longest adventitious root is as long as 2.1cm;Plant hormone had a significant influence on rooting rate,substrate had a significant influence on the longest adventitious root of Rhododendron hainanense.(5)In this experiment,Rhododendron hainanense's seeds were used as explants to establish aseptic materials.The optimal proliferation medium was WPM+1.0 mg/L IB A +0.2 mg/L TDZ,and the average proliferation multiple is 5.05;The optimum seedling medium was WPM+0.4mg/L IBA+ 0.2mg/L TDZ+1%AC,and month growth rate was up to the highest 0.96cm;The best rooting medium was WPM+1.0mg/L IBA +1.5mg/L NAA,the rooting rate was up to 94.44%,the average rooting number was up to 23.48.