ABSTRACT

In the Mediterranean climate, plants, e.g., Quercus brantii Lindl, have evolved and adapted to bear up low soil-water and soil-phosphorus conditions. Quercus brantii Lindl. is a dominant tree species thorough Zagros Mediterranean forests. Phosphate-solubilizing bacteria (PSB) play crucial role in the plant growth enhancement by solubilizing insoluble soil-phosphate. In the present study, the effects of two indigenous PSB strains, e.g., Microbacterium sp. (M.) and Streptomyces sp. (S.) were individually and combined evaluated on growth and physiological traits of Quercus brantii. seedlings under different water stress treatments. Results showed that maximum P- solubilization rate was observed by M. strain. Results also revealed that water stress increased electrolyte leakage and reduced relative water content in all plant compartments as well as growth parameters. Two PSB strains individually and in combination significantly enhanced growth and physiological traits of seedlings under both irrigation treatments compared with the non-inoculated seedlings. The M. strain showed higher potential for increasing of root length, weight and RWC compare to other PSB strain. Finally, the results suggested that application of isolated indigenous PSBs in reforestation could help to cope with the drought conditions in semi-arid Mediterranean Zagros forests by increasing of root and improving of oak seedlings growth.

摘要

在地中海气候中，植物，例如Quercus brantii Lindl，已经进化并适应了低土壤-水和土壤-磷的条件。Quercus brantii Lindl。是扎格罗斯地中海森林中的优势树种。磷酸盐溶解细菌（PSB）通过溶解不溶性土壤磷酸盐在植物生长促进中起关键作用。在本研究中，两种本地 PSB 菌株的影响，例如微杆菌属。(M.) 和链霉菌属。(S.) 对Quercus brantii 的生长和生理特性进行了单独和组合评估。不同水分胁迫处理下的幼苗。结果表明，最大P- 通过 M. 菌株观察到溶解率。结果还表明，水分胁迫增加了电解质泄漏并降低了所有植物隔室中的相对含水量以及生长参数。与未接种的幼苗相比，在两种灌溉处理下，单独和组合的两种 PSB 菌株均显着增强了幼苗的生长和生理性状。与其他 PSB 菌株相比，M. 菌株在增加根长、重量和 RWC 方面表现出更高的潜力。最后，结果表明，在重新造林中应用分离的本地 PSB 可以通过增加根系和改善橡树幼苗的生长来帮助应对半干旱地中海扎格罗斯森林的干旱条件。