6793

6335

كارشناسي ارشد

بيوتكنولوژي كشاورزي

اصفهان: دانشگاه صنعتي اصفهان، دانشكده كشاورزي

1390

پانزده، 123ص.: مصور، جدول، نمودار

ص.ع.به فارسي و انگليسي

مجيد طالبي، مسعود بهار

7/4/91

آقافخر مير لوحي، فرشيد نوربخش

1396/09/14

كتابنامه

كشاورزي

مهندسي كشاورزي

ID6335

به فارسي و انگليسي: قابل رويت در نسخه ديجيتالي

Identification of Rhizobia Containing of Nodulation Competitiveness and Effectiveness Genes Zakiyeh Ghorbani Sini z ghorbani s@yahoo com Date of submission February 8 2012 Department of Agricultural Biotechnology Isfahan University of Technology Isfahan 84156 83111 Iran Degree M Sc Language Farsi1 M Talebi Ph D Assist Professor Supervisor mtalebi@cc iut ac ir2 M Bahar Ph D Assoc Professor Supervisor mbahar@cc iut ac irAbstract Nitrogen is an essential nutrient for plant growth which is supplied through direct additions of chemicaland organic fertilizers and biological fixation Leguminous plants obtain their nitrogen by associatingwith symbiotic bacteria called Rhizobia which add significant amount of nitrogen into the soil Aneconomic exploitation of rhizobia legume symbiosis needs to inoculate the legumes with the superiorrhizobium strains that are efficient in nodulation and nitrogen fixation The application of commercialrhizobia is generally unsuccessful because of ecological incompatibility and low competition of thesebiological fertilizers against indigenous population of rhizobia Therefore selection of effective andcompetitive indigenous rhizobium strains is essential for their applications in different regions Somegenes such as nfe putA acdS and melanin production genes are involved in the nodulationcompetitiveness symbiotic effectiveness and stability of rhizobia under environmental stresses In thecurrent study we determined the presence of these genes in order to achieve information about nodulationcompetitiveness and symbiotic effectiveness of native Sinorhizobium isolates of Iran We alsoinvestigated the ability of melanin production in rhizobial isolates of alfalfa clover beans sainfoin grasspea and pea The specific medium was used for detection of melanin production Among symbioticstrains of alfalfa 106 isolates bean 55 isolates and clover 31 isolates this ability was observed in55 27 and 10 of isolates respectively According to PCR results with specific primers thefrequency of nfe putA and acdS genes in Sinorhizobium meliloti strains isolated from alfalfa nodules wasevaluated 6 73 and 93 respectively The nfe genes are directly involved in nodulation efficiencyand competitiveness of the S meliloti and only detected in highly competitive strains nodulating alfalfa In the present study for competition assays two S meliloti strains C81 4 and A11 8 with nfe genes werecoinoculated with 10 S meliloti strains without nfe genes in different treatments Based on the results the nfe positive isolates showed significantly higher nodule formation ability in comparison to the nfenegative isolates by occupying 86 100 of nodules The shoot dry weight of treatments containing C81 4and A11 8 was 79 and 72 higher than treatments inoculated with C72 4 and B53 1 without nfegenes strains and the negative control without inoculation respectively The A11 8 strain was

مجيد طالبي، مسعود بهار

آقافخر مير لوحي، فرشيد نوربخش