Study on the physiological indexes of the common plant populations in desertification process on the southeast edge of Mu Us Sandy Land

摘要

Studied on the physiological indexes(leaf water content, chlorophyll a, chlorophyll b, relative plasma membrane permeability, proline and Malondialdehyde(MDA)) of common plant populations(Stipa bungeana, Cleistogenes squarrosa, Lespedeza davurica, Artemisia ordosica, Cynanchum komarovii) in desertification process on the southeast edge of Mu Us Sandy Land. The results showed: During the process of desertification, the responses of different plants at different stages were different, the degree of damage and the ability of resistance also varied. For Stipa bungeana, the leaf water content, chlorophyll a, chlorophyll b decreased during the process of desertification, relative plasma membrane permeability and MDA increased constantly, the proline fluctuated and raised, indicated that it was damaged seriously and had strict requirements for habitat; for Cleistogenes squarrosa, the physiological responses were similar to Stipa bungeana, also had weak stress resistance; for Lespedeza davurica, the leaf water content was stable originally, then reduced at IV stage, chlorophyll a, chlorophyll b decreased, relative plasma membrane permeability and proline increased, MDA increased firstly and then decreased and further raised, but the variance range was lower, indicated that although the membrane system subjected to a certain degree of damage, it had self-adaptive response, the damage was to a lesser extent; for Artemisia ordosica, the leaf water content reduced at first, raised again from II stage, chlorophyll a, chlorophyll b also decreased at first and then increased gradually, relative plasma membrane permeability and proline raised at first and then kept stable at III stage, MDA fluctuated slightly with little changing, which showed the trend that increased firstly and then decreased and further raised, restrained the membrane lipid peroxidation cooperatively, membrane damage was not obvious; for Cynanchum komarovii, the physiological responses were similar to Artemisia ordosica.