تقويم كفاءة بعض العزلات المحلية للبكتريا Rizobium Leguminosarum المتخصصة على الماش في تثبيت النايتروجين في مستويات ملحية مختلفة

Abstract

This experiment was carried out under lath house conditions by using a completely randomized design with three replications to evaluate the response of mungbean (Vigna radiate) Cv. local plants to inoculation with six local isolates which specialized on R.leguminosarum isolated from plants at Baghdad and AlAnbar governorates. These isolates were symboled (Ab, Kh, Ra, Kr, Sk and Hl) in addition to one imported strain (M10) as well as non inoculation treatment to evaluate its growth under different salinity levels. Plastic pots supplemented with saline sandy loam soil of 3, 6 and 9 dS.m-1 . They were prepared by using drainage water with salinity 16 dS.m-1 Twenty seeds/pot were sown then thinned to 8 plants. Pot -1 . Soil moisture content was maintained at 60% of the water holding capacity during the experimental period of 60 days. After this period shoot and root dry weights, fresh weight, number of nodules were calculated. Soil content of Nitrogen was determined. The results could be summarized as follow:- Increasing soil salinity level from 3 to 9 dS.m-1 significantly reduced shoot and root dry weights. The reduction percentages in the two plant parts were 36.6% and 12.0% respectively. At the same time nodule numbers and fresh weights were decreased, and soil available nitrogen was decreased by 33.4%. Rhizobial inoculation caused a significant increasing in the shoot and root dry weights. Local isolate Kh showed the highest effect )not less 7% more than the other isolates and 21.7% more than imported strain .Isolate Kh showed significantly highest number of nodules which means that it is very necessary to utilize from the local isolates in the inoculation mungbean Rhizobia because of its adaptation to our environment and its reflection with positive form on plant growth.