Study Of Water Rlationships Of Haloxyllon spp. In Yazd

In spite of Haloxyllon Spp. is one of endemic plants on Iran center kavir and one of the most important of elements for sand fixation, but enough information are not available or noticeable about physiology and morphology behave for contrast with environment conditions. In order to study reaction of plant contrast with moisture stress that is the most important factor for limited of growth and development at plants on desert area. For this goal, design was carry out in four successive years (1999-2005) in Yazd shahidsadoge control desert research station and at near of manual plants. The design was started with structure and establishment number of 10 lysimeters with 122 centimeters diameter and 170 centimeters depth. Lysimeters were conforming to technical nuance and hatchways were used for accessibility to soil and root on depth: (30,60,90,120 centimeters). Next of lysimeters to be prepared, haloxyllon seedling were planted and annual nursing was provide for do moisture treatments. Moisture treatments were contained: Control(pot capacity), &#8531pot capacity and dry stress. All experiments were conducted in a completely randomized design with three replications. Requirement water for reach to enough moisture provide weekly and via weigh of lysimeters was accessible for plants. Imply at dry treatment next of plant complete establishment, irrigation was avoidance. For evaporation amount minimum of lysimeters surface, they were cover with fiberglass thin foil and one of lysimeters was use for counted of evaporation amount without plant. Sum of output water (Drain + Evaporation) was deducted from input water (Rainfall + Irrigation) and equipollent transpiration. Moisture treatment in during two of growth season was used and effect of it evaluated on morphological factors, contain: Height, diameter, canopy volume, number of main and minor branches, length of leaf, number of nude in unit per leaf length and physiological factors, contain: Plant water potential, leaf osmotic potential, root osmotic potential and relative water content (RWC). At end with remove and drying of shoot and root dry weights as well as shoot/root ratios of plants, and also water use efficiency (WUE) were measured. We studied distribute of roots weight and length, on soil different depths. For survey from interaction effects of environment factors, contain: Temperature on physiological factors, example: Plant water potential, leaf osmotic potential, root osmotic potential and relative water content, from July to October, seven times with 15 days interval were measured (with per measurement of trace from pridawn and afternoon). The results of this research suggest that among of morphological factors: shoot dry weight at 0/1% level of probability (&#945=0.001), leaf length at 1% level of probability (&#945=0.01), diameter of canopy at 5% level of probability (&#945=0.05) were affected of moisture treatment but tree height, volume of canopy, number of shoots and number of nude at leaf length unit had no significant effects. Plant water potential, leaf and root osmotic potential were affected of moisture treatment and at 0/1% level of probability (&#945=0.001) had significant effects. Also relative water content (RWC), and shoot/root ratios at 5% level of probability (&#945=0.05) had significant effects. On experiment all, times of measurement for physiological factors were significant at 0/1% level of probability (&#945=0.001) and different dates of measurement at 0/1% level of probability (&#945=0.001) were significant. Water use efficiency (WUE) was further with drying stress increase.