Effects of sand burial on growth and antioxidant enzyme activities of wheat （Triticum aestivum L.） in northern China

Growth and physiological responses of wheat to sand burial were studied in Horqin Sandy Land, to determine the impact on productivity and survival as well as antioxidant enzymes responses. This study consisted of one control(no sand) and four sand burial treatments: 25%, 50%, 75% and 100% of seedling height, respectively. Minor burial(25%) had no effect on wheat growth and survival; deep burial(100%) was fatal, and the others had an intermediate effect. Thus, the survival limit to sand burial was equal to seedling height. Sand burial mainly decreased shoot biomass and crop yield, but had small effects on belowground biomass. Superoxide dismutase(SOD) activity increased with time after burial in all treatments with surviving plants. Peroxidase(POD) activity increased after six days under burial, and catalase(CAT) activity decreased after burial, but recovered after 12 days. The concentration of malondialdehyde(MDA), a marker for oxidative stress, was low on the sixth day, but increased thereafter with burial depth. Thus, sand burial >25% should be avoided due to growth rate reduction leading to reduced crop yield, and even 25% burial showed physiological indicators of stress.