Investigation On The Resources Of Primula In Sichuan Province And Studies On The Cultivation And Reproduction Of Two Species Of Primulas

There are about 500 species in genus Primula in the world, of which approximately 300 species distribute in China, and most of them are famous alpine perennials with beautiful flowers and can be cultivated as garden plants and pot flowers. The Western part of Sichuan Province is one of the modern distributing centers. Although the Primula resources are abundant in China, most of them are still leaved in wild without sufficient researches. Climate change, natural disarsters and human activities can threaten wild resources. So, investigation and reseach are in urgent need. Firstly the Primula resources in Sichuan had been investigated. Places for investigation include Longchi in Dujiangyan, Baoxing, Kangding, Hailuogou in Luding, Dangling in Danba, Mount. Siguniang, Huanglong Scenic in Songpan. P. polyneura and P. cockburniana were chosen for further research including the biological characters of seed germination, cultivation technology in greenhouse and tissue culture.1,Totally 22 species were founded after investigation. Wide distribution of P. Sikkimensis, P. involucrate subsp. Yargongensis, P. amethystine subsp. Argutidens, P. secundiflora, P. cockburniana and P. palmate was found in several places and introduction should be easy. P. moupinensis, P. sonchifolia and P. orbicularis were found in several places with small populations. Distribution of P. odontocalyx, P. fasciculate, P. polyneura and P. alsophila was found in only one of these places but with large populations. Restrictively distribution was found of P. chienii, P. denticulate subsp. Sinodenticulata, P. szechuanica, P. obconica, P.deflexa, P. gemmifera, and P .limbata. Species with small populations and high ornamental value need to be protected under certain measures.2,The seed dormancy of P. polyneura can be removed by GA treatment. Pretreatment of seeds with higher GA3 concentration(200mg/L and 400mg/L )raised germination rate to 78.1% and 90.8% respectively and favorable temperature was in the range of 20~25℃. Seed germination rates of P. cockburniana were above 90% under different temperature conditions, but favorable temperature was in the range of 20~30℃. GA3 treatment only raised germination speed. Whether there was light or not, seed germination of P. polyneura had no significant difference under the same GA3 treatment. Lignt and GA3 both have significant effects on seed germination rate of P. cockburniana .Light had little effect on seed germination rate when GA concentration raised to 200mg/L and 400mg/L.3,P. cockburniana grew better than P. polyneura in greenhouse in Beijing, planted at the end of September, it took seven months to become a plant with four to five leaves. Planted at the same time, P. polyneura grew fast during two months after germination, but most of the plants gradually began to wilt with roots alive. Great difference between greenhouse and its habitat may account for the poor adaptability of P. polyneura.4,The effect of different culture media and sucrose concentration on seed germination were studied and an efficient protocol for in vitro plant regeneration via shoot regeneration from apical bud was developed. Optimal medium for seed germination of P. polyneura was MS with the highest germination rate at 38% and sucrose concentration had no effect on germination. The highest seed germination at 51.3% of P. cockburniana was obtained when cultured on 1/2 MS and a sucrose concentration higher than 20g/L resulted in lower germination. The highest propagation of P. polyneura, at 49.4%, was observed on medium supplemented with 0.5mg/L 6-BA and 0.01 mg/L NAA. While optimal medium of P. cockburniana was MS with 0.5mg/L 6-BA and 0.05mg/L NAA, and the highest propagation was 81.8%.To sum up, by the investigation on the wild resources and studies on the biological characters of seed germination, cultivation technology in greenhouse and tissue culture of the two species, it offered special reference to the introduction and commercial cultivation in the future of the wild Primula., germplasm resources preservation and breeding research.