نوع مقاله : مقاله پژوهشی
نویسندگان
1 استادیار گروه علوم خاک پردیس کشاورزی و منابع طبیعی دانشگاه تهران
2 گروه زراعت و اصلاح نباتات، پردیس کشاورزی و منابع طبیعی دانشگاه تهران، کرج، ایران
چکیده
کلیدواژهها
عنوان مقاله [English]
نویسندگان [English]
The performed researches during last decade have proved new perspective of rhizobacterial application. These researches show that rhizobia can cause growth and plant yield increase in different ways in spite of their main role in N2 fixation. So rhizobacteria are considered as plant growth-promoting rhizobacteria (PGPR) now. These bacteria can make nutrition improvement or plants health level increase in direct (plant growth hormones production, organic and inorganic insoluble phosphate solubilizing,…) and indirect(siderophore, HCN,…production) way, altogether they can cause products yield increase. One of the PGPR factors is HCN production ability to Proteobacteria and in many cases in Psudomonas. Certain rhizobia strains are recently introduced as Hydrogen Cyainde production bacteria too, several researching tasks have been performed on indigenous rhizobia but cyanogens ability has studied in none of them, so this research with the aim of HCN production effects on growth charactacterisitcs of some plants was planned and carried out for the first time in two laboratory and green-house stages as follow: At first, biochemical and microscpis tests were performed on 454 selected rhizobial isolates among different rhizobial genus. Suspension with the same population of 5*108 cfu.ml-1 were prepared from all pure and fresh rhizobial culture. HCN production ability determination was performed by Lock (1948), which was corrected by alstrom (1987), so rhizobial strains were grouped in cyanogenecy different levels from 1 to 4, as the least, almost low, almost high, the most in HCN production. Cyanogens super strains inoculants application effect and alfafa, wheat and corn yields in green house test were evaluated too. The results first prove rhizobacteria as cyanogens. 33 isolates (7.26%)from 454 rhizobial isolates had the ability of HCN production. Secondly, this ability is not the same in different strains. Abundance of the strains among different HCN production potential levels (1-4) were 10, 6, 11 and 6(2.2, 1.32, 2.42 and 1.32% the most abundance among cyanogens rhizobia belonges to both Rlv and S.m group (almost 80%) in return any of slow growing (Brady)rhizobia (Clycin Max and Peanut) was not able to produce HCN. The results of different plant growth promoting rhizobacteria inoculants application on legumes (alfalfa)and nonlegume plant (wheat and corn) also proves that inoculation of these plants with HCN productive rhizobial strain didn’t cause significant difference in any of measured items such as biological yield and plant yield in comparison with control treatment without fertilizer (Negative Control).
کلیدواژهها [English]
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