I= STUDIES ON FUNGI CAUSING SEED-BORNE DISEASES OF WHEAT AND RICE AND THEIR CONTROL
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Title of Thesis
STUDIES ON FUNGI CAUSING SEED-BORNE DISEASES OF WHEAT AND RICE AND THEIR CONTROL

Author(s)
Sardar Abdul Jamil Khan
Institute/University/Department Details
Department of Botany/ University of Karachi
Session
1992
Subject
Botany
Number of Pages
261
Keywords (Extracted from title, table of contents and abstract of thesis)
fungi, seed-borne diseases, wheat, rice, fungicides, ustilago tritic, urocystis tritic, loose smut of wheat, flag smut of wheat, karnal bunt, neovossia indica, stinking smut, ti11etia foetida, fusarium spp., alternaria sp., drechs1era spp.

Abstract
Wheat and rice fields of Pakistan were extensively surveyed during 1986-89 for important seed-borne diseases. Of the major seed-borne diseases, loose smut of wheat (Ustilago tritic) and flag smut of wheat (Urocystis tritic) were widely prevalent in all the four provinces of Pakistan; partial bunt or karnal bunt (Neovossia indica) in the central, northern Punjab and NWFP whereas complete bunt or stinking smut (Ti11etia foetida) was confined in the uplands of Balochistan and hilly areas of Punjab and NWFP. In the non-irrigated areas Fusarium spp., and in irrigated areas Alternaria sp., and Drechs1era spp., were associated with seed rot, foot rot and seedling blight of wheat. Of the seed-borne diseases of rice, blast disease of rice (Pyricu1aria oryzae) was a major disease in the central the arts of Punjab and a minor disease in Sindh, brown leaf spot of rice (Drechs1era oryzae)and kernel bunt of rice and barc1ayana) were prevalent in all the rice growing areas of Pakistan Using standard blotter, agar plate and deep freezing methods, 17 genera and 40 species of fungi Were isolated and identified from 450 seed samples of wheat and 26 genera and 54 species of fungi from 200 seed samples of rice. The occurrence 01 23 species of fungi viz., A1ternariagodetide A. raphani, Aspergillus candidus6 A. sulphureus, A. tamarii, A. terreus, Cephalosporium graminearum, Chaetomium crispatum. c.funicola, Cladosporium spherospermum, Curvularia clavata, c. robusta, Drechslera rostrata, Epicoccum purpurascens, Fusarium equiseti F. graminearum, F. nivale, Melanospora zamiae, Hemnoniella echinata, Myrothecoum roridum, Pencillium purpurogenum, Sporotrichum purinosporum and Stachybotrys atra on wheat seeds and 31 species of fungi viz., Alternaria lonqipes, A. raphani, Aspergillus candidus, A. sulphureus, R. terreus, Botrytis atra, Cephaliophora irregularis, Chlalaropsis thielavioides, Curvularia clavata, c. eragrdstidis, C. in termedia , C. penniseti, C. tuberculata, Drechslera australiensis, D. biseptata,D.ha I odes ,D.rostrata, D. specifera, Fusarium avenaceum, F nivale F. semitectum, Helicodendron paradoxum, Memnoniella ecninata, Myrothecium roridum, Penicillium purpurogenum, Pithomyces graminicola, Stachybotrys atra, S. dichora, Staphylotrichum cocosporum, Tetraploa ellisii and Trichothecium rosem On rice seeds are being reported for the first time from Pakistan. Of the different isolation techniques used, blotter method proved better for quantitative analysis and agar plate method for qualitative analysis of seed-borne fungi. Alternaria spp., and Fusarium spp., were conveniently isolated by blotter method and species of Curvularia and Drechslera by agar plate method. The deep freezing method was found more effective for the isolation of deep seated seed-borne fungi like Drechslera oryzae, Gerlachia aryzae, Fusarium moniliforme, Trichoconis padwickii and Drechslera soroliniana.

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S. No. Chapter Title of the Chapters Page Size (KB)
1 0 Contents
157.55 KB
2 1 Materials And Methods 1
91.65 KB
  1.1 Collection Of Seed Sample 4
  1.2 Determination Of Seed Health 4
  1.3 Use Of Fungicides For Seed Treatment 12
  1.4 Methods For Scoring Various Seed-Borne Diseases Of Wheat And Rice 14
  1.5 Statistical Analysis Of Data 15
3 2 Experimental Results 16
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  2.1 Techniques For The Detection Of 16
  2.2 Occurrence Of Seed-Borne Fungi On Wheat 41
  2.3 Effect Of Weather On The Incidence Of Seed-Borne Disease Of Wheat Under Different Agro-Ecological Zones In Pakistan 54
  2.4 Effect Of Seed-Borne Fungi On Seed Germination Under Laboratory And Field Conditions 62
  2.5 Effect Of Varying Dosages Of Inoculum In The Development Of Complete Bunt Of Wheat 68
  2.6 Status Of Tilletia Foetida Vs. T. Caries, The Cause Of Complete Bunt Of Wheat In Pakistan 72
  2.7 Effect Of Fungicides On Germination Of Wheat Seeds 74
  2.8 Effect Of Fungicides In The Control Of Seed-Borne Fungal Infection 79
  2.9 Evaluation Of Wheat Varieties For Resistance 96
4 3 Experimental Results 103
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  3.1 Evaluation Of Various Methods For The Detection Of Seed-Borne Fungi Of Rice 103
  3.2 Inducing Sporulation In Seed-Borne Fungi Of Rice 124
  3.3 Occurrence Of Seed-Borne Fungi On Rice 129
  3.4 Effect Of Seed-Borne Fungi On Seed Germination Under Laboratory And Field Conditions 146
  3.5 Effect Of Fungicides On Germination Of Rice Seed 160
  3.6 Effect Of Seed Treatment Before Storage On Germination Of Rice Seed 164
  3.7 Effect Of Seed Treatment On Seed-Borne Fungal Infection 168
  3.8 Effect Of Fungicides In The Control Of Seed-Borne Fungal Infection Of Rice 175
  3.9 Occurrence On Stack Burn Disease Of Rice Caused By T. Padwickii Ganguly In Pakistan 188
  3.10 A Note On Quick Identification Of Seed-Borne Fungi Of Rice 190
5 4 Discussion 197
164.58 KB
6 5 Appendices 219
146.87 KB
  5.1 List Of Seed-Borne Fungi Of Wheat And Rice In Pakistan 219
  5.2 Description Of Fungi Isolated From Seed Of Wheat And Rice Not Reported Form Pakistan 230
7 6 References 239
417.66 KB
  6.1 Acknowledgements 260
  6.2 Reprints Of Paper Published 262