I= IMPROVING NODULATION IN LENTIL THROUGH CO-INOCULATION WITH RHIZOBIA AND ACC-DEAMINASE CONTAINING PLANT
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Title of Thesis
IMPROVING NODULATION IN LENTIL THROUGH CO-INOCULATION WITH RHIZOBIA AND ACC-DEAMINASE CONTAINING PLANT

Author(s)
MUHAMMAD ZAFAR-ULHYE
Institute/University/Department Details
Institute of Soil & Environmental Sciences/ University of Agriculture, Faisalabad
Session
2008
Subject
Soil Sciences
Number of Pages
199
Keywords (Extracted from title, table of contents and abstract of thesis)
nodulation, lentil, co-inoculation, rhizobia, acc-deaminase, legumes, rhizobacteria, nodules, nodulation, gnotobiotic conditions, axenic conditions

Abstract
There is a mutualistic symbiotic association between legumes and rhizobia, which results in the formation of nodules (nitroegn fixing sites) on the roots of legumes. In addition to other factors, plant hormones have an important role in developing and establishing nodules. Some plant growth promoting rhizobcteria promote nodulation by lowering endogenous levels of plant hormone ethylene in roots through their l-aminocyclopropane-l-carboxylate(ACC)-deaminase activity. So co-inoculation of lentil with rhizobia and plant growth promoting rhizobacteria (PGPR) containing ACC-deaminase, might improve nodulation. A series of experiments were conducted under gnotobiotic, wire house (pot) and field conditions to study the effect of co-inoculation on nodulation in lentil. Several strains of rhizobia were isolated from lentil nodules on yeast extract mannitol (YEM) medium and those of plant growth promoting rhizobacteria containing ACC-deaminase on minimal salt medium with ACC as sole nitrogen source. The collected rhizobial strains were screened for their ability to cause nodulation and PGPR strains for their growth promoting activity under gnotobiotic conditions. All possible combinations of the selected rhizobial and PGPR isolates were tested under gnotobiotic conditions for improving nodulation to screen the best combinations. The role of the selected combinations and rhizobial and PGPR strains included in the combinations, was evaluated for improving nodulation and growth of lentil through co-inoculation in pot and field trials. The selected rhizobial as well as plant growth promoting rhizobacterial strains containing ACC deaminase were characterized for plant growth promoting attributes. It was observed that inoculation with rhizobia or PGPR containing ACC-deaminase alone improved nodulation/growth of lentil over control under natural conditions. Moreover, co-inoculation with rhizobia and ACC-deaminase containing plant growth promoting rhizobacteria further improved nodulation and growth of lentil as compared to singl-strain-inoculation. In a classical triple response study, it was also observed that the selected PGPR containing ACC-deaminase diluted the effects of exogenously applied ACC.

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3695.19 KB
S. No. Chapter Title of the Chapters Page Size (KB)
1 0 Contents
201.37 KB
2 1 Introduction 01
69.47 KB
3 2 Review Of Literature 07
499.95 KB
  2.1 Lentil 07
  2.2 Rhizobia 09
  2.3 Nodulation 10
  2.4 Rhizobium Inoculation Of Legumes -A Results Oriented Practice 16
  2.5 Plant Growth Promoting Rhizobacteria 19
  2.6 Ethylene 23
  2.7 Ethylene -An Inhibitor Of Root Growth And Nodulation 25
  2.8 ACC- Deaminase 28
  2.9 Plant Growth Promoting Rhizobacteria Containing ACC- Deaminase Affect Plant Growth 32
  2.10 Combined Effects Of Rhizobia And Plant Growth Promoting Rhizobacteria On Nodulation And Plant Growth 37
4 3 Materials And Methods 43
234.49 KB
  3.1 Isolation Of Rhizobacteria And Rhizobia 43
  3.2 Screening Of Rhizobacteria Containing ACC- Deaminase 45
  3.3 Screening Of Rhizobial Strains Under Gnotobiotic Conditions 47
  3.4 Screening Of Efficient Rhizobial/Rhizobacterial Combinations Under Axenic Conditions 48
  3.5 Effect Of Co-Inoculation On Nodulation And Growth Of Lentil Under Natural Conditions 51
  3.6 Characterization Of Rhizobia And PGPR Strains 53
  3.7 Identification Of Strains 57
  3.8 Classical Triple Response Bioassay 57
  3.9 Soil And Plant Analysis 58
  3.10 Statistical Analysis 58
5 4 Results 60
2396.43 KB
  4.1 Screening Of Rhizobacteria 60
  4.2 Screening Of Rhizobial Strains Under Gnotobiotic Conditions 71
  4.3 Screening Of Efficient Rhizobial / Rhizobacterial Combinations Under Axenic Conditions 80
  4.4 Effect Of Inoculation/Co-Inoculation On Nodulation And Growth Of Lentil Under Natural Conditions 90
  4.5 Classical Triple Respose Trial 147
  4.6 Identification And Characterization Of The Selected PGPR And Rhizobial 149
6 5 Discussion 152
140.13 KB
7 6 Summary 163
57.33 KB
8 7 Conclusions 168
342.4 KB
  7.1 References 169