Responses Of Syringa To Water Stress

Clove is a commonly landscape tree which has strong habit and good adaptability, so it is easy to cultivation and management for the resistance of cold, drought, barren. The growth and survival of cloves are often subject to water logging threat. This test selected the commonly Heilongjiang garden clove as materials used in water logging. It studied on the flooding stress response of one year of Syringa oblate and Syringa microphylla seedlings, three years of syringa vulgaris, Syringa reticulata, Syringa emodi, syringa meyeri and Syringa oblate fom the point of morphology and physiology. The anti-flood of different cloves was compared, the part reason of clove flooding differences in adaptive was revealed, and the strong anti-flood clove species apply to afforestation and ornament was selected in final. It provided basic theoretical for the deep study of water logging of plants and had a great practical significance to the science arrangement and solution land use of submergence on the garden. The major findings are as follows:(1) One year of the anti-flood capacity of Syringa microphylla was slightly stronger than Syringa oblate; Flooding stress did not inhibit the root activity of two and both presented a rise trend during the entire flood; The chlorophyll content of two seedlings slowly reduced as the time of flood; The PDC and ADH of Syringa oblate and Syringa microphylla leaves and roots manifested increased first and then decreased and both enzyme activity were higher in leaves, compared with Syringa microphylla, roots and leaves of Syringa oblate flooded 8 days maintained a relatively high activity of PDC and ADH, LDH activity of clove itself is lower and is still a low level after flooding, lactic acid fermentation is not the main anaerobic respiration means of cloves, and ethanol fermentation anaerobic respiration as the main means of cloves to play a key role; The SOD and POD activity were different, POD activity was significantly higher in Syringa microphylla, Syringa oblate with poor anti-flood SOD and POD activity declined rapidly after flooded and had been lower than untreated ago, while in Syringa microphylla early has down, then rised and maintained a certain level, higher than the activity before flooding; MDA content was increased both in two cloves, Syringa microphylla had a higher level.In summary, the anti-flood capacity of Syringa microphylla slightly stronger than Syringa oblate, water logging stress serious harmed two cloves survival. In order to avoid affects of excessive moisture on the growth of clove seedlings, it should choose suitable environment and strengthen water management in clove cultivation.(2) The three-year-seedling cloves'morphology changes reflected its anti-flood ability in visual. It was consistent basically in relative conductivity and MDA content. The order of clove's anti-flood:syringa vulgaris first, Syringa reticulata, and Syringa emodi second, syringa meyeri and Syringa oblate third; Anaerobic respiratory enzymes PDC and ADH activity first increased and then decreased in every leaves, SOD and POD protective enzymes were induced, but had different changes. Through analysis and comparison, the anti-flood of cloves was opposite to increase rate of ADH activity. POD and SOD played a more important role in clove's growth and its increase rate was same as adaptability in flooding stress. Overall, three years seedlings of 5 cloves could survival under short flooding, with extend of flooding time, the poor anti-flood syringa meyeri and Syringa oblate hurt seriously, syringa vulgaris, Syringa reticulata, Syringa emodi showed a strong anti-flood capacity, were more suitable as greening tree species in low-lying city and along the river.ADH activity in leaves was suitable as an indicator of clove moisture tolerance. It could be studied further at the molecular level, so as to nurture strong anti-flood clove varieties.