| This paper is based on the preliminary research of microbial fertilizers applying effect, mechanism on promoting some plants growth and colonizing dynamics in the rhizosphere of wheat. About 20 different strains were selected from 11 spieces of bacteria or mycorrhizal fungi, and were made into kinds of microbial fertilizers. After inoculated on seeds or used on the roots of the muskmelon, watermelon, wheat and peanuts they could enhance their height dry weight, or improve their ability of uptaking nutrient element, or increase the number of nodules of peanut. When these microbial fertilizers were sprayed on the leaf of muskmelon, some of them remarkably suppressed disease of Mycosphaerella melon is. By means of HPLC(high-performance-liquid-chromatography), many kinds of mctabolites were tested in the fermentation solution of these bacteria.(1)Most of the stains produced various physiology-active materials to stimulate and regulate plant growth, such as phytohormones: 0 Indole-3-Acetic-Acid (IAA,average measure 6.8-20.5 ii g/l OOml) ; Gibberelin(GA3,average measure 23.4-46.8 i.?gIlOOml,but in B4 was 890.6 p gIlOOml): ç”–eatin(Z):B3, CCTCC93O38 and AS 1.108 could separately be tested 798.7 æ…½ gIlOOml, 857.1 p gIlOOml and 617.6 ii g/lOOml; OSolely B3 could be detected ABA, 7.6 i.z gIlOOml.(2)Further experiments show that some of bacteria could produce water-soluble vitamin riboflavin(VB2) and nicotinic acids (VB5).(3)Many kinds of organic acids, such as citric, malic, succinic, lactic and acetic acids could be tested .As for the intermediates of TCA cycle, they can promote plant growth.(4)Analysis on intracellular free amino acids shows most of the bacteria could produce them to help plant growth. A practical~ simple and reliable marking and detecting method is need for the strains of microbial fertilizers releasing soil environment. The existing plasmid E.coli DH52 (pTRIO2+ LuxAB) used as a LUXAB genes donor, and E.coliMM294(pTR2O13) used as a helper to respectively conjugate with B. megateriumATCC 14581, PsfluorescensAS 1.867. and Ps. fluorescens 3-PHB.By triparental mating, ATCC1458I-L,AS1.867-L and 3-PHB-L three new strains marked by LuxAB gene were successfully obtained .The colonizing dynamics and distribution of the luminescent bacteria ATCC14581-L, AS1.867-L and 3-PHB-L in the rhizosphere of wheat plant in rhizoboxes were stUdied by the method of X-ray filIn imaging andenumeration of luminescent colonies on agar media. The results showed thatthem all successfully colonized in the rhizosPhere of wheat. In rhizoboxes ofsterile soil the cultUre reached the highest level 2.54xl05, 9.67x106 and6.90x l0'ceq root were after 7 days. the population of tkem trended to bestable and decreased to 8.57xl02, 4.93xl03 and 4.47xl0'cfu/g rootrespectively after l6 day; On the contfeq, in rhizoboxes ofunsterile soil, thehighest colonizing level was 8.87xl04, l.4lxl05 and 7.7lx l05 cfu/g rootrespectively after 7 day On l6th day, the POpul8tiOn of them trended to astationary state and reduced to 4.74x l03, 2.27x l0' and 5.30x l05 cfiI/g root.On the l6th day, only ASl.867-L was testOd frOm 8cm to l6cm underseed,while the others Inarke strains were not.
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