Researches On Cultivation And Adaptability Of Two Fan Flower Varieties

Researches on cultivation and adaptability of two Australian fan flower varieties Scaevola albida’Mauve Clusters’and S. albida’Dream White’were carried out in this paper. Firstly, growth characteristics in Wuhan and under different sun light conditions were observed. Secondly, experiments were designed for heat stress (two varieties; temperatures:25℃,30℃,35℃,40℃,45℃), drought stress (two varieties; drought treatments:4d,8d,12d), and rewatering after 8d and 12d of drought stress respectively to research the physiological and biochemical changes of the two varieties, including leaf’s relative water content, content of chlorophyll, MDA, Pro, soluble protein and soluble sugar, leaf’s relative conductivities, enzyme activity of SOD and POD. Main results were as following:(1) The plants of the two cultivars in field returned to green in early spring, flowered late in March; they grew fast and were fully blooming from April to June; but they grew poor from July to August; from September to Mid-November, the plants grew well and were fully blooming again; the flowering period was more than 9 months; they started to wilt in December. The plant of Mauve Clusters was 8-13 cm high with prostrate branches, and its flowers were pale blue. The plant of Dream White was 20-25 cm high, its flowers were white and dense and bloomed earlier than Mauve Clusters, therefore has high ornamental value.(2) With shade increasing, the two varieties’plant height, crown width, stem diameter and chlorophyll a/b decreased, but the leaf area per gram increased. The chlorophyll content of Mauve Clusters increased with the shade increasing, while that of Dream White increased at first and then decreased. Under shade, the leaves of Mauve Clusters was significantly thinner than that of Dream White, stomata density and the tissue of palisade/spongy of Mauve Clusters were all less than that of Dream White. All these showed that Mauve Clusters was moer shade-tolerant than Dream White.(3) Under heat stress, leaf relative water content of the two varieties decreased; chlorophyll content increased at first and then decreased; MDA content ascended gradually; Pro, soluble protein and sugar content increased all together; SOD and POD activities increased at first and decreased later, and differences between the two varieties were all significant, but differences in relative conductivities between the varieties were not significant. These showed that Dream White’s heat resistance was stronger than Mauve Clusters. (4) Under drought stress, leaf relative water content of the two varieties decreased; chlorophyll content of Mauve Clusters increased at first and decreased later, while that of Dream White decreased gradually in the whole test period. The leaf relative water content and chlorophyll content of the two varieties had different degrees of recovery, but the chlorophyll content of Dream White under 12 days drought still decreased after rewatering. Membrane permeability and MDA content increased with the drought stress intensified and decreased after rewatering. Pro, soluble protein and sugar content of the two varieties all gradually increased with drought time increasing, but soluble sugar content of Dream White decreased after 12 days of drought stress. These three indexes changed greatly after rewatering. SOD and POD activities all increased at first and decreased later and gradually returned to the initial. level after rewatering, but POD activity of Dream White under 12 days drought stress still increased after rewatering. Through comprehensive analysis, Dream White was more drought-resistant than Mauve Clusters.