Thumbnail Image

M. Sc. Dissertations

Browse

20131
Reset filters
Subject: Agricultural Microbiology × Author: Kuldeep × Start date: 2010 × Type: Thesis × Thesis Type: M.Sc ×
Reset filters

Search Results

Now showing 1 - 1 of 1
  • Thumbnail Image
    ThesisItemOpen Access
    Phenetic and genetic analysis of abiotic stress tolerant Pigeon pea [Cajanus cajan (L.) Millspaugh] rhizobia retrieved from South-Western parts of Haryana
    (CCSHAU, 2013) Kuldeep; Gera, Rajesh
    Pigeon pea [Cajanus cajan (L.) Millspaugh] commonly called as toor dal or arhar dal is a perennial member of the family Fabaceae. It is an important legume mainly grown as hardy and drought tolerant crop. Environmental stress is a major component of natural selection in soil ecosystem. Among several environmental conditions, the most prominent problematic abiotic factors in the arid regions are drought and high temperature. For successful functioning of microbial bioinoculants and their influence on plant growth and soil health, exhaustive efforts have been made to expose microbial diversity, their distribution and behavior. Studies on molecular diversity of root nodule bacteria in rhizosphere or nodules have been conducted to classify these rhizobia and also to correlate with symbiotic properties, effectiveness and competitiveness of these bacteria. In the present investigation, a total 196 rhizobial isolates were obtained from 84 soil samples collected from SouthWest Haryana using trap plant to study the diversity of rhizobia nodulating pigeon pea. All the rhizobial isolates tested were able to grow at all the three temperatures i.e. 30, 35 and 40, except few isolates where growth was slightly suppressed at 40 o C. However, only 44 rhizobial isolates were able to grow at 45 o C, out of which some showed good, moderate and poor growth. Most of rhizobial isolates were able to grow up to 20% PEG. However, there was drastic decrease in their growth rate with increasing PEG concentration. Only, 71 and 3 rhizobial isolates were able to grow at 30 and 40% PEG, respectively. All the selected rhizobial isolates were also characterized for IAA production, siderophore production, P-solublization, ACC utilization and molecular characterization. The genomic DNA of all these rhizobial isolates were isolated by CTAB method and tested for nodC and nifH gene primers and hence authenticated as rhizobia. Genomic DNA of all the rhizobial isolates were also amplified with 16S rDNA gene primers using 27F and 1378R primers. The amplified product was subjected to RFLP analysis with MspI and HaeIII restriction enzymes. Dendrogram based on 16S rDNA profiles showed lot of diversity. Analysis of pigeon pea rhizobial isolates on ARDRA basis, 18 different biotypes were formed at 80% similarity coefficient. Most prevalent biotype was 13 th type, which prevails in all the four districts. On the basis of abiotic stress tolerance, biochemical and molecular characterization, six pigeon pea rhizobial isolates (PPH-8E, PPR-2, PPB-26A, PPM-30A, PPM-33C and PPM-37A) were selected as most efficient rhizobial isolates.