An Analysis On Moisture Suitibility Of Six Landscape Shrub Species In Northern China

Virescence shrubs with good drought resistance are of great importance for the construction of the ecological environment such as urban green space, plants landscaping. In this study, the capacity of drought resistence of Cornus alba, Weigela florida'Red Prince', Cerasus glandulosa, Ligustrum obtusifolium, Salix integra'Hakuro Nishiki'and Lonicera maackii were comprehensively evaluated by the determination of water and physiological and biochemical parameters using the two-year old seedling of each species as the object of investigation.The experiment was performed via pot-water control method and the soil moisture content for pot culture was set to A-55%, B-45%, C-35% and D-25%, inrespectively. The main contents of study were as follows:1. To determine different water parameters for the six species by pressure chamber and PV method during water control;2. To investigate the effect of drought stress for the six species on photosynthesis, transpiration, intercellular CO2 concentration and water use efficiency;3. To determine the physiological index of the six species and seedling growth under water stress condition.The results showed that:with the decline of soil moisture content, the capacity of osmotic adjustment and maintaining turgor pressure of Cornus alba, Weigela florida'Red Prince', Ligustrum obtusifolium and Salix integra 'Hakuro Nishiki'showed the trend enhanced under water stress; the capacity of osmotic adjustment and maintaining turgor pressure for Cerasus glandulosa and Lonicera maackii declined, while bound water content was increased and the capacity of cell absorption and water-retention was becoming strong, which could maintain turgor through themselves organizational flexibility. Drought stress has produced different effects on the photosynthetic capacity, of the six species. With the intensification of drought stress, net photosynthesis rate, stomatal conductance, light compensation point and water use efficiency declined, but intercellular CO2 concentration increased. The chlorophyll content for the six species declined, conductivity and MDA content were all increased, which indicated that all of the six species were hurted with different degrees. Intracellular soluble sugar content of the six species increased, which could decrease the osmotic potential of protoplasm, make cells continue to absorb water from outside media that water potential declined to maintain their normal metabolic activities and enhance drought tolerance of plant.According to the above results, the six species showed a certain measure differences in drought resistance. Under drought stress, the six species could adapt to drought through their different ways. Comprehensive drought resistance:Salix integra 'Hakuro Nishiki'> Ligustrum obtusifolium> Weigela florida'Red Prince'> Cornus alba> Cerasus glandulosa> Lonicera maackii.