[Allelopathy of Phragmites australis on Spartina alterniflora under different salinity]

Using Phragmites australis litter as test material, two kinds of its mother liquid, i. e., water extract and decomposed products, were obtained by the methods of solution extraction and anaerobic decomposition. The two liquids with concentration 100% and 25% were used to treat the seeds and seedlings of Spartina alterniflora and the endemic beneficial fungi (Mortierella sp.) of S. alterniflora under 5 per thousand and 10 per thousand salinity, aimed to study the effects of different salinity on the germination and growth of S. alterniflora and the growth of the fungi. Salt stress promoted the seed germination and young root growth of Spartina alterniflora as well as the growth of Mortierella sp. significantly (P<0.05). The water extracts promoted the germination and growth of Spartina alterniflora and the growth of Mortierella sp. when the salinity was 10%o, but the promotion effect disappeared when the salinity was reduced to 5 per thousand. The decomposed products of Phragmites australis restrained the germination of Spartina alterniflora significantly (P<0.05) when the salinity was 5 per thousand, but promoted the growth of Mortierella sp. significantly (P<0.05) when the salinity was 10 per thousand. Under the two salinities, the decomposed products restrained the growth of Spartina alterniflora seedlings and young roots significantly (P<0.05).