| Preliminary investigation and analysis on the distribution of Daphne genkwa were studied by sample inspection, consulting literature, field investigations and telephone interview. Genetic diversity and genetic structure between 6 populations of Daphne genkwa were analyzed by ISSR markers. Pollen morphology was observed by scanning electronic microscope(SEM), and its viability was measured by TTC and sucrose in vitro culture methods. Stigma receptivity by benzidine testing, H2O2 testing, and seed germination was observerd. The results were showed as follows:1. Daphne genkwa is distributed throughout the country, from Ganzhou City, Jiangxi province(24°N) to Meixian County, Shanxi province(33°N); from Tibetan autonomous region, sichuan province (101°E or so) to the zhoushan islands, zhejiang province(121°E). Daphne genkwa populations represent a patch-shaped distribution, most of companion species are culinary herbs, only a handful of them are trees, shrubs or vine. Population structure of Daphne genkwa is unreasonable and degenerate. It reproduced by seeds or sprouted buds. The growing environment were destroyed seriously, the distribution reduced, amount of population and individual declined quickly.2. The optimal PCR system(20μl) for ISSR analysis was Mg2+:2μl(2.5mmol/L), dNTP: 1.6μl(0.2mmol/L), TaqDNA:0.2μl(1.0u), Primer:1.6μl(0.8μmol/L), template DNA:2μl(40ng/μl), Buffer:2μl, H2O2:10.6μl. Genetic diversity and genetic structure among 6 populations of Daphne genkwa were analyzed by ISSR markers.229 loci were observed among the 180 samples from 6 populations using 11 primers. As analyzed by POPGENE32, the Daphne genkwa's value of observed PPB, number of alleles, effective number of alleles, Nei's gene diversity and Shannon information index were 40.17%,0.3724,1.9869,1.3767 and 0.2355, respectively. The level of genetic diversity of Daphne genkwa was in low level. Genetic differentiation coefficient (Gst) and gene flow (Nm) of Daphne genkwa were 0.4409 and 0.6340. Dendrogram was built by UPGMA based on Nei's genetic distances.3. Pollen is stenopalynous type with a diamer of 15.6-21.6μm. Per pollen has 10-16 apertures which is irregular circular. Surface ornamentation of pollen is rough reticulate pattern which is circular polygon (tetragon-heptaong, mostly pentagon-hexagon). Pollen viability is 48%, the highest value of stigma receptivity was 50% at 2 days flowering. Pollen germinated on stigma. Fruit is black and small. Embryo and decorticated seed germinated normally, However, intact seed hardly germinated, which indicated that the seed possesses the character of dormancy. Sucrose of different concentrations has a significant effect on pollen germination rate during pollen culture. And pollen germination rate is the highest with a percentage of 27.0% in medium containing 50g/L sucrose, while pollen could not germinate in medium containing sucrose over 250 g/L.4. The reasons for Daphne genkwa being endangered may be as below descript:First, seeds were too few to reproduce normally; second, it is difficult to restore for this kind of resources during a short time after its environment destroyed and excessive utilizing of human beings. For protecting Daphne genkwa and effective utilization, this paper proposes effective approaches which include in situ conservation, ex situ conservation, artificial propagation, information system of endangered species.
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