Studies On Developmental Physiology Of Bulbs And Physiological Changes Of Leaves Under NaCl Stress In Lycoris

Seven physiological indexes of the bulbs in developmental stages of L.radiate, L. aurea, L. chinensis, L. longituba, L. sprengeri, L. squamigera, L. anhuiensis and L. albiflora were studied in this paper, the dynamic changes of nine physiological indexes of the L. radiate leaves under NaCl stress were analysised, and so were the ten physiological indexes of the leaves under NaCl stress of L. radiate, L. houdyshelii, L. aurea, L. longituba, L. sprengeri, L. squamigera, L. anhuiensis. The results were as follows:1. SOD and POD were very important enzymes involved in scavenging system of active oxygen. The activities of SOD and POD became high during florescence, and they also growed high in the species emerging leaves. These observations showed that the activities of SOD and POD were changed with the growth and the reproduction of plant changed, and the changes of POD activity lagged behind that of SOD.2. For the eight researched species, the change of protein contents reflected the changes of activities in plants. The variations of solubal protein contents of bulbs were basically the same. The protien content rose gradually from March to May , added shortdatedly during florescence in August, and increased obviously in October for the leaf-emergence-in-autumn species.These might have some relations with the protien expression in the course of the bud differentiation and leaf emergence. The changing tendencies of the soluble and insoluble protein contents were the same basically.3. The soluble sugar and starch were the main deposited and transportation forms of carbon nutrient in bulbs of Lycoris Herb. They were also the foundation of energy and substance when the bulb dormancy was broken. The reducing suger was used as a kind of signal molecule in plants. In March, the contents of soluble suger and strarch were low, because the bulbs of Lycoris Herb. were the source of carbon nutrient in the bud differentiation stage, the starch was the transitory form which stored carbohydrates, and the soluble suger as the form of carbon nutrient appllied to the overground part of plants. In May and October, the content of starch was high in the species which emerge leaves in spring and autumn respectively, the bulbs of Lycoris Herb. were the storeroom of carbon nutrient in the photosynthesis stage, the products of photosynthesis were accumulated for bulbs in the form of startch. The content of reducing suger changed irregularly, maybe it related to its function.4. Under the stress of NaCl with different concentrations, the changes of foliar morphological and micromorphological structures were researched, and the dynamic changes of nine physiological indexes were also studied. It showed that the degrees of effects of NaCl on morphological and micromorphological structures increased as the NaCl concentration increased, such as the change of foliar length and the injuried degree in cell, and so on. With the NaCl concentration increased and time prolonged, the activities of SOD and POD first became higher then lower, and so were the contents of insoluble protein, proline and starch. As for the content of soluble protein , the changes were the opposite. The cotent of soluble suger and MDA increased as a whole. The content of reducing suger changed irregularly.5. Compared with the changes of ten physiological indexes and morphological structures of leaves under different NaCl concentrations, it was found that seven species of Lycoris Herb. were all influenced by different concentrations of NaCl, moreover, the effect of 1mol/L NaCl treatment was more powerful than others. Among the species which were researched, L. sprengeri, L. squamigera and L. anhuiensis had stronger tolerance to NaCl, and L. aurea had weakest tolerance of all.