Abstract: lastic sheet mulching could coordinate water,nutrient,air and heat in soil,which creats a good ecological environment for winter wheat growth and development.The mulch has significantly raised the temperature under the film.The decreased accumulated temperature by late sowing was compensated by increased accumulated temperature,and winter wheat was proceeded through their vernalization stage to photostage;at the some time,the spikelet differentiation periods were prolonged.This is the basic reason for the higher yield of wheat under plastic sheet mulching than cultivated without film covering.

Key words: Enteromorpha linza, Enteromorpha prolifera, seawater, growth, chlorophyll fluorescence parameter, osmotic adjustment ability.