| Sorbus pohuashanensis is the rarely tree that it has important economical and ecologicalvalue in the north forest district of China. Through research on characteristic of physiologicalecology of and seedling, the theory groundwork were established for that to estimate itsadaptive and the quantity in the stage of seedling. The conclusion was inferred through studyabout seed quantity, seed viability, absolute germination rate, mean germination time and thephotosynthesis and transpiration of two years juvenile:1. The weight of a thousand of S. pohuashanensis seed is 2.1721g, to be smaller than thatof average of the arbor seed;its seed filling is quite low, and Tonghua provenance is the mosthigh, it is 59.31%. Seed weight, Seed quantity and Seed contain water capacity of S.pohuashanensis from different provenances have remarkable difference. From northeast towestsouth in S. pohuashanensis natural distribution, S. pohuashanensis seed more and morebig and weight;and seed filling have relations with longitude, latitude, altitude andprecipitation.2. The experimentation point to: every provenance's seed viability is agreement on theregular of variation through differently method that they was store up. Fresh seed is most highthan other method, secondary method is dry storage in low-temperature for 5 months. Thisresult show that S. pohuashanensis seed ought to be stored in the conditions of dry andlow-temperature if the seed shouldn't be sowed after collecting seed. The variation ofdifferent provenance's seed viability is related with mean temperature of a year, and theirrelationship is the opposite direction. While the concentration of GA is between 0.1g·L-1 and0.2g·L-1, seed's germination rate is encouraged, but very high concentration of GA wouldrestrain that. Absolute germination rate and mean germination time of different provenance'sseed are related with latitude. From north to south, absolute germination rate more and morehigh, mean germination time more and more short. The sequence of seed quantity ofdifferently provenance's S. pohuashanensis is: Changbai>Tonghua>Hailin>Baihe>Dailing>Wangqing>Mudanjiang.3. Because the environment factors have diurnal regular, the plant's net photosynthesisrate, transpiration rate and water use efficiency also have similarly diurnal regular. In a fineday, the daily variation of net photosynthetic rate, transpiration rate and water use efficiencywere identical, but their highest peak value differ greatly. The daily variation of netphotosynthetic rate in leaves from different provenances presented single-peak curve, 'middaydepression' phenomenon weren't occurred, and the peak value appeared at 10:00-12:00. Atdifferent stage, Physioecological characteristic from different provenances have remarkabledifference.4. The photosynthesis of S. Pohuashanensis were effected by the interaction of a fewecological factors, and also the effect of interaction were large that of single factor. In normalweather, the light saturation point of young S. pohuashanensis leaves was between 1100 and1300 μmol/m2s, the light compensation point was between 16.7 and 32.5 μmol/m2s;the CO2saturation point was between 998.82 and 1194.25 μmol/mol, and the CO2 compensation pointwas between 34.54 and 57.64 μmol/mol. Different provenance's light and CO2 saturationpoint has relations with longitude and latitude. Light compensation point has relations withlongitude and altitude. Mean annual precipitation and mean annual temperature haveinfluence to those, and then the effect of frost-free period is very small. |
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