The Research Of Growth And Physiological Characteristics Of Enduring Drought On Introduced Ornamental Plants Swainsona Formosa

Swainsona formosa (Sturt's desert pea) is a genus of leguminous herbs salsula,natived to Australia.Because of it's colored brightly and adapt to the arid desert environment of Australia,it was both good ornamental and drought-type germplasm.Swainsona formosa was introduced to China and observed the growth and reproduction of which and explored initially growth performance and drought tolerance in Inner Mongolia. What we do can improve the biological characteristics of Swainsona formosa and will be an important reference value testin rational development and utilization.We determined the seed germination and plants growth and growth performance and physiological and biochemical indicators in different soil types and different gradient of drought stress conditions. The main results were as fllows:1 At the respect of seeds germination rate of Swainsona formosa, the soil added perlite had higher germination rate than loam soil in lab. Germination rate in cups was also show that adding perlite to soil can effectively promote seed germination and growth in taejon cultivate.2 The growth of Swainsona formosa in taejon was better than in laboratory culture, and the growth in the soil added to FeSO4 and perlite performanced good.Add perlite and FeSO4 in soil can increased soil permeability and reduce the soil pH, promoting the growth and cong increased of Swainsona formosa3 Introduced the Swainsona formosa in Inner Mongolia and grown in field, we observed that the growth of it approximately 65 days then it into the flowering stage and the flowering from the end of July to mid-September, about 50 days and the flowering rate up to 80%. However, due to the impact of longer spring freeze in 2010 and the late sowing time, leading to the effects of the early frost, all the plants wilting death and seeds had a low pod and quality. All the life history of the Swainsona formosa needed further observation.4 We researched the water tolerance of Swainsona formosa, grown it in lab in August, twenty-four hours without water and leaves to show symptoms of water shortage, four days without water, braches beaned and withered, the leaves began dry and yellow after five days,then given rehydration the leaves will not re-green. Some of the same kinds of flowers in the laboratory can still full of leaves without water about forty-eight hours, wilting rare. Swainsona formosa were growing well if it was been given water every day in the field cultivation.5 Swainsona formosa can growth both in mixed sand and loam soil in lad under the drought stress. When it was been twelve days for drought stress,there was no restrictivein to height of Swainsona formosa. When it was been twenty-four days for drought stress, the drought stress has begun to impact on the growth of plants. When it was been thirty-six days for drought stress, the plant height in moderate and severe drought stress was lower than mild drought stress significantly.6 As the drought intensifies, the content of proline, free amino acids, superoxide dismutase (SOD) and malondialdehyde (MDA) increased gradually in the two soils, which showed that Swainsona formosa adjusted adaptability to drought stress. The content of soluble sugar and soluble protein changes inconsistent and there was an interaction between osmolyte compensation, this compensation can be effectively allocated the role of osmotic adjustment, osmolytes better to play the role of osmotic adjustment.7 At the aspects of the protection enzymes, the mutual adjustment role among three kinds of protective enzymes (SOD, CAT and POD) can maintain the integrity of the Swainsona formosa and reduce the degree of membrane poisoned. The content of MDA rised in the two soil under drought stress, which indicated that drought stress contributed to the cell membrane lipid peroxidation of Swainsona formosa significantly and it suffered drought damage. Correlation analysis showed that, in addition to the soluble sugar and soluble protein, proline, amino acids, MDA and three kinds of protective enzymes had certain relevance in the two soils, and related with soil moisture content closely.8 Correlation analysis showed thatthe correlation of soluble sugar and soluble protein and other related physiological and biochemical indicators was less in the mixture sandy soil,but which was good in the loam soil. In addition, proline, amino acids, MDA and the three kinds of protective enzymes (SOD, POD and CAT) had certain relevance in the two soils, and is closely related with soil moisture content. The relationship in the two kinds soils can make Swainsona formosa adapt to drought stress and grow normally ultimately.