Studies On Ecological Adaptation Mechanism Of Alpine Understory Plants Erythronium Sibiricum

In this paper, the Erythronium sibiricum as the research object, through its anatomical,photosynthetic physiology, cold resistance physiological characteristics, leaf pigment changes and theseed germination characteristics were studied to reveal Erythronium sibiricum adapt alpine understoryhabitats and ecological adaptation mechanism, the results as follows:1、Anatomy and its ecological adaptation of Erythronium sibiricum was studied, the resultswere shown that: there was significant parenchyma in subterranean scale leaf, which providedsufficient location of water and nutriment for Erythronium sibiricum during its above10-monthdormancy every year. Spring ephemerals have high photosynthetic rates that allow them to rapidlyaccumulate carbohydrates and complete their aboveground growth in a few weeks. To sustain highphotosynthetic rates in early spring, the plants must be able to absorb water efficiently at low soiltemperatures and to allocate large amounts of nutrients to the shoot to compensate for lowerenzymatic activity at low temperatures. Stem (scape) of Erythronium sibiricum consisted ofepidermis, ground tissue and sparsate closed vascular bundles. There was a thick layer ofcuticle on the epidermis, which could save inside water from evaporation, lots of vascularswere able to ensure water absorption from cold soil and nutrients allocation to shoot efficiently.There was significant phloem fiber in every bundle that played a very important role in bearing largeflower or fruit on the top of the stem. Leaf was large and thin with little cuticle on the epidermis,which not only could lessen sunlight reflection, but also enlarged photosynthetic surface. Besidesspongy tissue, there was an other kind of special mesophyll tissue “Level-palisade tissue” inasssimilating tissue constituted with layers of elongate cells, whose macro-axis was paralle with theleaf epidermis, it means a significantly enlarged photosynthetic tissue area, suggesting an adaptationto the habitat of Erythronium sibiricum under the forest where the sunlight was not sufficient. Therewere densy veins both inside of leaf and parianth, which acted a keystone role in sustaining enoughwater supply, sustaining cell normal turgor pressure, sustaining optimal spatial showing pattern ofleaf and parianth, and in improving pollination efficiency, ensuring reproductive success. It was alsothe result of the long-period adaptation of the plant to its shadow forest habitat, where the pollinatorswere not reliable.2、 Leaf expansion, flowering and fruiting stage Erythronium sibiricum have a higher netphotosynthetic rate (Pn), has provided a guarantee for Erythronium sibiricum rapid growth. Threedifferent periods of （Pn）diurnal variation patterns are bimodal, at14:00“midday depression”phenomenon, the net photosynthetic rate of the average was flowering> fruit stage> leafexpansion; transpirationsimilar rate (E) and stomatal conductance (Gs) of the diurnal variation ofnet photosynthetic rate curve, showed obvious bimodal peak times sync with the netphotosynthetic rate, transpiration rate of the day average was flowering> fruit period> leaf expansion; the stomatal conductance day the average was fruit stage> flowering> leaf expansion.3、 Different periods of Erythronium sibiricum by Low temperature stress, SOD, CATactivity, soluble sugar content and proline have varying degrees of increase, with the decrease oftemperature and processing time extended physiological indicators content increase in both,performance strong stress resistance and tolerance to low temperature.4、After different temperature processed, Erythronium sibiricum leaf chlorophyll content andanthocyanin content have obvious changed.25/20°C and14/4°C different periods of Erythroniumsibiricum chlorophyll content compared with CK were significantly increased;5/0℃differentperiods of Erythronium sibiricum chlorophyll content tended to decrease compared with CK.Erythronium sibiricum leaf anthocyanin content changes contrary to the above results, as thetemperature decreases anthocyanin content was significantly increased compared with CK,indicating that the low temperature is conducive to the accumulation of anthocyanins. Differentlight Erythronium sibiricum chlorophyll content increased with increasing light intensity,anthocyanin content compared with CK, have a generally downward trend.5、4°C conditions,0.5%KNO3processing Erythronium sibiricum seeds germinationphenomenon appears in nearly120days, the germination rate was87%. The other approach didnot germination.