Gera, RajeshHarshpreet, Kaur2017-06-032017-06-032014http://krishikosh.egranth.ac.in/handle/1/5810014076The problem of the salinity or sodicity existed long before the start of agricultural practices. It has now become a very serious problem for crop production, particularly in arid and semi-arid regions, which constitute about one third of the world’s land surface. Irrigation water always includes some amount of dissolved substances, collectively called salts. Due to inadequate and unassured supplies of good quality water in many arid and semi-arid regions of the world, farmers use saline or sodic ground water for irrigation of crops. Long-term and indiscriminate use of such water causes accumulation of salts, particularly Na, which not only adversely affects the physical and chemical properties of soil, but also modifies the quality of soil organic carbon and its biotic components. Saline water is categorized as water with an EC > 4.00 deciSiemens / meter (dS/m) while sodic water is categorized as water with an RSC > 2.5me/l. The effects of salinity or sodicity on soil chemical and physical properties are well known and their effects on the soil microbial community and microbiological processes remain relatively unstudied. Thus keeping in view the above facts, a total of 15 saline water irrigated rhizospheric soil along with their respective water samples were collected from Hisar, Jind, Sirsa and Rewari districts. The pH and ECiw of these water samples varied from 6.00 - 8.20 and 2.48 - 17.14 dS/m respectively. Their respective soil samples were analyzed for pH, ECe, organic C, total N and total P, which varied from 6.04 - 8.10, 4.10 - 21.00 dS/m, 0.13 - 0.45%, 0.012 - 0.044 % and 587 - 703 mg P/kg soil, respectively. Similarly, a total of 20 sodic water irrigated rhizospheric soil and their respective water samples were also collected from Hisar, Mahendergarh, Karnal and Kaithal districts. The water samples were analyzed for the RSC, pH and ECiw, which was above 2.50 me/l, 8.50 - 10.90 and 1.01 - 1.50 dS/m, respectively. The pH, ECe, organic C, total N and total P of soil samples ranged from 8.30 - 10.50, 1.00 - 2.40 dS/m, 0.09 - 0.46%, 0.002 - 0.040% and 625 - 701 mg P/kg soil, respectively. The viable counts of bacteria for the above soil samples collected from saline and sodic soils were taken on Jensen’s, malate, Pikovaskaya, King’s B media and soil extract agar. It was observed that with the increase in EC, there was decrease in viable counts. A total of 215 morphotypes were obtained from the above 35 different soil samples, out of which 91 and 124 morphotypes belonged to saline and sodic soils, respectively. Most of these morphotypes were identified as gram -ve rods, cocci and small rods in addition to some fraction of gram +ve small rods and cocci. All these morphotypes were characterized for agriculturally useful traits such as P-solublization, siderophore production, IAA production and ammonia excretion. Out of 91 morphotypes obtained from saline and 124 morphotypes from sodic soils, only 15 and 18 morphotypes, respectively, were found to have all the above four characteristics. In saline soil, more numbers of morphotypes were ammonia excreters while in sodic soil, IAA producers were present more in numbers.The genomic DNA of the morphotypes obtained on soil extract, Jensen’s and malate media was isolated by the CTAB method and was amplified for nifH gene by using degenerative primers, nifH for and nifH rev. Out of 57 morphotypes obtained from saline soil and 86 morphotypes obtained from sodic soil, 28 and 42 morphotypes, respectively, showed nifH gene amplification, indicating that these morphotypss can fix nitrogen. The efficiency of six promising bacterial morphotypes isolated each from saline (JK246, JJ355, SK543, JS 509, RS 502 and JP323) and sodic soils (KtJ571, KtK569, KrK564, KrS530, KrS546 andKtP390) were checked in wheat variety KRL 210 at different levels of induced salinity having an EC of 0, 4, 8 and 12 dS/m and sodicity with RSC 0, 10 and 15 me/l, respectively. The bacterial counts were less in uninoculated plants as compared to inoculated one. Moreover, in all the treatments, the total bacterial counts were higher at 45th day of sowing then the counts recorded before sowing and as the crop reached to maturity, the viable counts start decreasing. Best results were observed at EC 4 dS/m and RSC 10 me/l in terms of plant height, no. of tillers, plant dry weight and mean grain weight. The significant difference with respect to these parameters was observed in all the induced EC or RSC levels. The inoculation of different morphotypes isolated from saline or sodic soils resulted in a significant increase in plant growth parameters as compared to control or uninoculated plants. In all the treatments with different EC or RSC levels, the consortia performed better as compared to individual morphotypes and the reference strains i.e. Mac 27 and P-36 in terms of plant growth parameters both in saline (SK543+ JS 509+ RS 502+ JP323) as well as sodic (KrK564+ KrS530+ KrS546+ KtP390) soils.enbiomass, tropical zones, area, productivity, biological phenomena, land resources, vegetative propagation, nutrients, storage, remote sensingThesis