Study On The Marine Microorganims With Potential Pesticide Inducing Plant Antisalt Talerance

550 strains isolated from different marinie environments (reserved in our laboratory) were screened for the antimicrobial activity and insecticidal activity.8 strains with pesticide potential were obtained and were then applied to investigate their plant-antisalt-inducing abilities. The results were as follows:1 The harmful critical point concentration of inorganic salts was determined as 0.6% through the pre-test.4 strains (B-9987, YM, FC02, BBY9-4) were prescreened under above mentioned salt concentration through tomatos seed germination promotion test. Then tomato seed under salt stress and simulated salty soil were treated with the 4 strains respectively and tomato seedlings biomass, defense enzymes' activities the Na+, K+ concentration of tomato in vivo were measured as indexes. The results showed that strain FC02, B-9987 and YM could obviously increase tomato seedlings biomass. As for defense enzymes' activities, different strains caused different defense enzyme activity increase compared to control with B-9987 increased SOD activity 38.01%, FC02 increased CAT activity 144.1% and NTYM—0112 increased POD activity 22.3%. As for Na+, K+ concentration index, B-9987 increased K+ concentration 36.09% in leaves and at the same time decreased Na+ accumulation in root with 39.5%.2 The inducing plant-antisalt mechanism was conducted using B-9987, NTYM—0112 and FC02 as test strains and the results showed that 3 strains could in varied degree decrease tomato salt damage and increse survival rate and water content in dry weight of tomato seedling thus indicated certain relieving salt damage ability. Compared to the situation under salt stress, the above mentoned 3 strains changed tomato biochemical composition in different ways. Tomatos treated with B-9987 5 days later, its chlorophyll content increased 40.0%, malondialdehyde content decreased 42.6%, proline content increased 78% and soluble sugar content increased 43.7%. While tomatos treated with FC02 7 days later, its chlorophyll content increased 37.3%, malondialdehyde content decreased 29.7%, proline content increased 120% and soluble sugar content increased 40.9%. As for tamotos treated with NTYM—0112 7 days later, its chlorophyll content increased 55.8%, malondialdehyde content decreased 38.5%, proline content increased 138% and soluble sugar content increased 44.9%.3 The colonization of B-9987 which was previously biomarkered with Rifampicin in tamoto cultivated in seeding soil, simulate saline soil and natural saline soil respectively was investigated. The results showed that B-9987 could colonize in rhizosphere soil and different organs of tomato. The B-9987 root colonization in simulate saline soil was preferable than natural saline soil with the maximum colonization in the former 1.03×105cfu/g and decreased to 1.54×103cfu/g 15days later while in the later 7.64×104cfu/g and decreased to 64cfu/g 15days later.