The Effects Of Arbuscular Mycorrhizal Fungi In The Response Of Plant To Soil Drought Stress

Drought is the main limiting factor for side slope vegetation restoration. Hydrogel, scientific irrigation, and the side slope melioration have been used to relieve the water stress. However, such non-biological methods would increase the cost. VAM could enhance plant resistance to such stress and advance the ecological restoration process. But there were few researches on the effects of VAM on side slop vegetation. Therefore, pot experiments were conducted to exam the effects of VAM in the response to drought stress (water relative content of soil was 45-55% ) of plants (Kummerowia striata, and Lespedeza formosd) growing in two kinds of soil media with different nutrient level. The results are as follows.1. The effects of different soil and water media on the VAM colonization rateThe differences of VAM colonization rate was studied on plants grown on two soil media (nutritional medium and lean medium) and different water contents(drought stress: relative water content of soil 45-55%; normal condition: 70-80%). The results show that VAM colonization rate of K. striata was significantly higher than that in L formosa. Under drought stress, the VAM colonization rate of plant grown in highly-nutrient medium was 38.15% {Kummerowia striata) and 52.47% (Lespedeza Formosa) higher than lowly-nutrient mediumand.2. The physiological and ecological response of plants to soil drought stressCompared to lowly-nutrient medium, Plants grown in highly-nutrient medium showed less changes in water and Proline content but greater change in soluble sugar content under drought stress. Higher plant biomass was found grown in highly-nutrient medium under drought stress. Under drought stress, branch numbers of K.striata and L. formosa increased by 4.6 and 1.7 times respectively grown in highly-nutrient medium compared to grown lowly-nutrient medium. Shoot and root biomass increased by 4.48 and 0.68 times respectively in K.striata, and 4.30 and 1.03 times respectively in L. formosa. Plant N and P content were also higher n highly-nutrient medium compared to grown, lowly-nutrient medium.3. Effects of AMF on the physiological and ecological responses of plants to drought stressCompared with the non-AMF inoculated treatments, AMF inoculated plants showed higher chlorophyll content, lower MDA content and higher soluble sugar content. The water relative content of leaf and Proline content changed diferently. AMF increased the branches number of K. striata, plant height of L. formosa, and biomass of both species. AMF increased the phosphorus and nitrogen content of shoot, but decreased phosphorus and nitrogen content of root. AMF increased the total phosphorus and nitrogen content of both shoots and roots.