| Puionium Gaertn is a biennial herbaceous vegetable of cruciferous plants, a specially inhabiting in Mongolian plateau, including P.cornutum(L.)Gaertn.and P.dolabratum Maxim. P.cornutum(L.)Gaertn is a special species in China and P.dolabratum Maxim is listed an endangered species in 1992. In this thesis, in terms of seed germination, seedling growth, water physiology, pollination mechanism and reproductive development so on, the physiological and ecological adaptation of Puionium Gaertn was investigated and estimated, which can offer theoretical guidance and technical support for sand-fixing, provide theoretical basis for the survival and reproduction of the sand plants. The main findings are as follows:1. Physiological and ecological adaptation of seed germination(1) The soil moisture contents of P.cornutum and P.dolabratum fruit germination can range from 2% to 20%, the best suitable germination is 6% to 12%; the soil moisture content which the seedling of fruits can be grow can range from 3% to 20%, the seedling of seeds can be grow can range from 3% to 16%; the best suitable seedling growing of all fruit and seed can range from 6% to 16%.(2) P.cornutum and P.dolabratum have the biggest biomass in 6% to 12% of the soil water content, have the significantly highest Root-top ratio respectively in 3% to 8% and 4% to 8%.(3) The best appropriate burial depth of P.cornutum and P.dolabratum are respectively 2cm and 1cm. The best suitable water supply are respectively 135ml and 90ml, then the best appropriate amount of monthly rainfall arel50ml and 100ml.The sand burial depth of seedling emergence:when the water supply for the 45ml, all are 1-4cm; when water supply are 90m, respectively are 1-8cm and 0-4cm; when the water supply of 135ml, respectively are 1-8cm and 0-8cm.2. Physiological and ecological adaption of seedling growing(1) P.cornutum and P.dolabratum have some flexibility to the high temperature, while a variety of symptoms of heat injury to P.cornutum always be later than P.dolabratum,about 1-3h later.(2) At a temperature of 25-50℃range, PS II reaction center not damaged or affected. when the temperature rises to 60℃, PSⅡreaction center by the damage has been increased significantly; heat should be 40-50℃.P.cornutum should be a very stronger heat resistance than P.dolabratum.(3) P.cornutum and P.dolabratum were buried 1/3 which promote its growth,2/3 which inhibit their growth; seedling survival rate of all burial was 0%,2/3 were respectively 80% and 60%,1/2 and 1/3 were respectively 100%.3. Physiological and ecological adaptation of the moisture physiology(1) The moisture Physiological indexes have't significantly different between P.cornutum and P.dolabratum. Water potential changes in a single peak curve,11:00-15:00 in the lowest value.(2) P.cornutum and P.dolabratum dehydration rate degree of change in the state of nature is similar. The turning inflexion respectively is 12.77h and 11.00h.(3) The soil moisture around the biennial roots of P.cornutum and P.dolabratum were 3.13±0.46%,1.90±0.68%; the annual roots were 2.68±0.11%,2.50±0.45%.(4) The main roots of P.cornutum and P.dolabratum are vertical, horizontal roots system are very strong; the lateral roots distribution of the annual have maximum in the soil depth of 20-40cm; the largest regions for the distribution were the depth of 20-40cm, the radius within the range of 0-40cm; the lateral roots distribution of the biennial is largest in the soil depth of 40-60cm; the largest regions for the distribution is the depth of 40-60cm, the radius of 0-40cm away from the main root. The amount of lateral root of roots of P.cornutum is logarithmic decreased; the amount of lateral roots of P.dolabratum is exponential decreased, with increasing distance from the root.4. Megasporogenesis and microsporogenesis; Female and male gametophyte(1) The cytokinesis of the microspore mother cell is the successive type. The microspore tetrads are tetrahedron. The mature pollens are 3 cells.(2) The anther have 4chambers.The anther wall development type is dicotyledons. Tapetum is the secretory type.(3) Each locule contains the two ovules. The mature ovules are curve. The enlbryo sac is Polygonum type.(4) The female gametophyte is later than male gametophyte. The female inflorescence is beginning to grow when the male inflorescence is developing to monocyte microspore.5. Pollination Biology(1) P.cornutum and P.dolabratum reaches its full boom respectively in 18:00-19:00 and 19:00-20:00 in the natural population。(2) The pollen germinating percentage of P.cornutum and P.dolabratum reached the highest on the media supplemented respectively with 25% sucrose,0.001% Boric acid and 30% sucrose,0.005% Boric acid; The most congenial temperature of pollen germinating is 25℃,and effective temperature is 15-38℃;The pollen can reach highest peak from the biggest white flower bud to 16h after blooming; Low temperature (4℃) is advantage to pollen storaging. The stigma of P.cornutum and P.dolabratum had highest receptivitied from 24h to 48h after blooming.(3) Wind is very weak during pollinating for P.cornutum. Investigation showed that there are 19 and12 species flower visiting insects in the natural populations of P.cornutum and P.dolabratum. The frequency of pollinators in the natural populations was bimodal curve, the peak were 7:00-11:00 and 15:00-20:00.The visiting frequency of P.cornutum is up to 150 times every day, less than 7 times of P.dolabratum. The role of pollinating insects on P.dolabratum is very weak.
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