I= ROLE OF MINERAL NUTRIENTS IN RESISTANCE TO LEAF CURL VIRUS IN COTTON (GOSSYPIUM HIRSUTUM L)
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Title of Thesis
ROLE OF MINERAL NUTRIENTS IN RESISTANCE TO LEAF CURL VIRUS IN COTTON (GOSSYPIUM HIRSUTUM L)

Author(s)
Zafar Ullah
Institute/University/Department Details
Institute of Pure & Applied Biology/ Bahauddin Zakariya University Multan
Session
2003
Subject
Biology
Number of Pages
270
Keywords (Extracted from title, table of contents and abstract of thesis)
mineral nutrients, leaf curl virus, cotton, gossypium hirsutum l, bemisia tabaci, cim-448, leaf epicuticular wax, s-12, niab-krishma, plant growth

Abstract
Cotton leaf curl virus (CLCuV), transmitted by whitefly Bemisia tabaci, causes one of the most devastating diseases of cotton. Disease symptoms, which appear on leaves, are thickening of midribs and veins and development of enation. Disease resistant cotton cultivar CIM-448 had high leaf epicuticular wax. Electron micrographic of midribs showed the sever effects of virus on vascular elements in S-12 (CLCuV susceptible), whereas no such effects were observed in NIAB-Krishma (moderately CLCuV-resistant) and CIM-448 (CLCuV-resistant) reflecting their differential degree of resistance to CLCuV.

To probe the relationships between some macro-nutrients like N, P, K and Ca and resistance to cotton leaf curl virus (CLCu V) in cotton, two genetically different cultivars (S-12, CLCuV susceptible and CIM-448, CLCuV resistant) were grown in sand culture under high and low N, P, K and Ca regimes in respect of that in full strength of Hoagland’s nutrient solution. The varying N regimes of the growth medium were 224,112, and 56 mg L-l in Hoagland's nutrient solution. Similarly, for P, 62.00, 31.00, 15.50 and 3.88 mg L-l, for K, 236,120, and 40 mg L-1, and for Ca, 320,160,80, and 20 mg L-l were maintained in Hoagland’s nutrient solution. Leaf epicuticular wax, chlorophyll a, b and a/b ratio, soluble proteins, free amino acids, water relation parameters and gas exchange properties were measured. After harvest, fresh and dry biomass, leaf area, ion contents, soluble sugars and starch content of the plant tissues were determined.

From all these results, it was evident that highly disease resistant CIM-448 and highly susceptible S-12 were less affected by alteration in nutrition. S-12 remained susceptible under various nutrients except at lower N and P, at which growth and virus 2incidence had been reduced to some extent. However, higher external K concentrations in susceptible plants alleviated disease incidence. Patterns of ion accumulation were same in both cultivars under altered as well as under normal conditions. Pattern of accumulation of soluble sugars and free amino acids were also same as under normal conditions. Although disease cannot be eliminated by any specific nutrient, but incidence of disease was reduced particularly with the addition of K. From the results presented here, it is recommended that disease incidence can be considerably reduced by N, P, and K nutrition in proper combination. All this work will widen our existing knowledge and provide basis for modifying current agricultural practices to reduce disease incidence in cotton.

Download Full Thesis
2461.68 KB
S. No. Chapter Title of the Chapters Page Size (KB)
1 0 Contents
210.45 KB
2 1 General Introduction 3
245.42 KB
  1.1 Importance Of Cotton 3
  1.2 Role Of Cotton In Pakistan Economy 4
  1.3 Genetic Architecture Of Cotton 5
  1.4 Relationship Between Mineral Nutrients And Plant Growth 10
  1.5 Relationship Between Mineral Nutrients And Plant Diseases And Pests 18
  1.6 Cotton Leaf Curl Virus( CLCuV ) 22
3 2 Some Morpho -Anatomical And Physiological Characteristics In Resistant And Susceptible Cotton Cultivars/ Lines Infected With Cotton Leaf Curl Virus ( CLCuV ) 27
353.02 KB
  2.1 Introduction 27
  2.2 Materials And Methods 28
  2.3 Statistical Analysis Of Data 31
  2.4 Results 32
  2.5 Discussion 46
  2.6 References 50
4 3 Effect Of Different Nitrogen Levels On Two Cultivars Of Cotton ( Gossypium Hirsutum L) Differing In Resistance To Cotton Leaf Curl Virus ( CLCuV ) 54
433.22 KB
  3.1 Introduction 54
  3.2 Objectives 58
  3.3 Materials And Methods 59
  3.4 Statistical Analysis Of Data 63
  3.5 Results 63
  3.6 Discussion 92
  3.7 References 95
5 4 Effect Of Different Levels Of Phosphorus On Two Cultivars Of Cotton ( Gossypium Hirsutum L.) Differing In Resistance To Cotton Leaf Curl Virus ( CLCuV ) Susceptible Cotton Cultivars/Lines Infected With Cotton Leaf Curl Virus ( CLCuV ) 103
379.12 KB
  4.1 Introduction 103
  4.2 Objectives 106
  4.3 Materials And Methods 106
  4.4 Statistical Analysis Of Data 110
  4.5 Results 111
  4.6 Discussion 139
  4.7 References 143
6 5 Effect Of High And Low Levels Of Potassium On Two Cultivars Of Cotton ( Gossypium Hirsutum L.) Differing In Resistance To Cotton Leaf Curl Virus( CLCuV ) 148
470.95 KB
  5.1 Introduction 148
  5.2 Objectives 155
  5.3 Materials And Methods 155
  5.4 Statistical Analysis Of Data 159
  5.5 Results 160
  5.6 Discussion 187
  5.7 References 191
7 6 Effect Of Different Regimes Of Calcium On Two Cultivars Of Cotton ( Gossypium Hirsutum L.) Differing In Resistance To Cotton Leaf Curl Virus( CLCuV ) 202
251.46 KB
  6.1 Introduction 202
  6.2 Objectives 204
  6.3 Materials And Methods 205
  6.4 Statistical Analysis Of Data 208
  6.5 Results 209
  6.6 Discussion 227
  6.7 References 230
8 7 General Discussions 233
454.13 KB
  7.1 Conclusions 238
  7.2 Bibliography 240