| Ferns (Pteridophyta) is the lowest level of higher plants, is the most primitive population ofhigher plants, the early terrestrial plants, by spores offspring, is the vibrant herb. Approximately12,000kinds, our more than2,600species have been identified, accounting for20percent ofglobal multi-fern resources on Earth ferns, China has many special varieties. With the deteriorationof the natural environment, and some of the most valuable resources (such as Cyatheaceae plants)have been on the verge of extinction. How basic research (such as breeding techniques, externalenvironmental factors on the ferns and fern conservation), etc., rational development andutilization of resources and protection of scarce resources fern is realistic. In recent years, throughfragrant Dryopteris artificial breeding and tissue culture, to understand the incense Dryopterisspore germination and gametophyte development process; further study the temperature and pH oftheir spore germination and early gametophyte development, so as to formulate the developmentand utilization program of science and conservation measures.(1) media choices, chose fragrant Dryopteris spore culture medium used soil and solid media,including MS,1/2MS,1/4MS,1/8MS and modified Knop’s formula (NaH2PO40.2g, KNO30.2g,MgSO40.2g, Ca(NO3)20.8g, distilled water1000mL), agar concentration of0.8%. Dryopterisspores carried incense culture propagation, spore germination and gametophyte development of thewhole process. Hong Dryopteris spore germination type book with fern(Vittaria-type),gametophyte development approach for trigeminal fern type.(2) Researched the different temperatures, salt concentration, GA3content and pH affect theincense Dryopteris spore germination and gametophyte development, the results showed that thetemperature of the Hong Dryopteris spore germination was not significant, storage temperatureaffect Hong Dryopteris gametophyte development was not significant, could develop normally,just as the temperature change occurred at different times spore germination. Low incubationtemperature could limit the membrane permeability and enzyme activity, thereby affecting fernspore germination rate, at25℃Dryopteris fragrans appeared the highest germination rate. Withthe changes in the concentration of inorganic salt content of the medium, the germination rate wasdeclining, showed significant differences; same growth conditions gametophyte was also verysignificant differences existed between the different concentrations of salt processing. Inoculatedwith spores could germinate GA3treatment on different mediums, but the germination rate showedno significant differences, GA3medium concentration of0.2mg/L was suitable incense Dryopterisspore germination and gametophyte development. pH in the4.4-6.8range of spore germinationrate was not significantly different, but the germination time significant differences existed,indicating that Hong Dryopteris spore germination and gametophyte development were moresuitable under acidic conditions, which in Dryopteris fragrans consistent performance of the wildhabitat. (3) further tested the incense Dryopteris sporozoites seedling water content, membranepermeability, chlorophyll content in response to low temperature stress. Conclusion: tissue culturespore water content decreased with decreasing temperature, bound water/free water ratio increasedfirst and then decreased as the changing trend, which is the plant during the winter by reducing theintensity of metabolism to adapt to adverse conditions. Under cold stress, seedlings of sporozoiteschange the relative conductivity analysis of variance showed that, as the temperature decreasingDryopteris fragrans membrane system for low growth environment made some adaptation. Withthe decreasing of temperature stress, incense Dryopteris sporozoites chlorophyll content ofseedlings increased first and then decreased, and inconsistent with the natural conditions, spores indifferent period might be in different reaction to temperature change. |
PDF Full Text Request