Effect of Adding Perlite in Soil on Some Growth and Physiology Characteristics of Queues castanifolia Seedlings under Water deficit Stress

Queues castanifoliais one of the most demanded species for reforestation in Golestan province. It is necessary to produce appropriate seedlings in nurseries.  This study was carried out to determine the effect of perlite on soil on growth and physiological responses of Queues castanifolia seedlings under water deficit stress. A factorial experiment was conducted as randomized complete block design in greenhouse condition of agricultural and natural resources research Center in Gorgan, 2015. Perlite treatments in 4 levels (0, 15, 25 and 35% (V/V)) was added in soil and water stress in 3 levels (40, 70 and 100% irrigation at field capacity) for 5 months were applied in the pot experiment. Some parameters including gas exchange (photosynthesis, stomatal conduction and transpiration) and leaf water potential of seedlings, diameter and height growth and dry weight of root, stem, leaf, and seedlings were measured in different treatments at the end of the experiment period. The results showed that all parameters were affected by different levels of irrigation and perlite. Water deficit to 40% FC reduced 51% and 68% of photosynthesis and stomatal conductance respectively. The highest diameter and height growth and dry weight of the seedlings were observed in 25% and 35% (V/V) perlite application under normal and stress conditions, respectively. The use of perlite alleviated the negative effects of water deficit and ameliorated seedling growth. It could be suggested that perlite application in soil is suitable for the production of desirable seedlings under water deficit condition.