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STUDIES ON SOME SEED-BORNE FUNGAL DISEASES OF TOMATO

Perveen, Shahida (1996) STUDIES ON SOME SEED-BORNE FUNGAL DISEASES OF TOMATO. PhD thesis, University of Karachi, Karachi.

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Abstract

Using blotter, agar plate and deep-freezing method as recommended by ISTA, the seed borne mycoflora of 24 samples of tomato seeds collected from vegetable markets of different parts of Pakistan was examined. Agar plate method yielded greater number of fungi followed by blotter and deep-freezing method. Of the 20 genera and 37 species of fungi viz., Alternaria alternate, A. tenuissima, Aspergillus candidus, A. flavus, A. fumigatus, A. niger, A. quadrilineatus, A. flavus, A. niger, A. quadrilineatus, A. sulphureus, A. terreus, A. wentii. Aspergillus sp., Auriobasidium pullulans, Cephaliophora irregularis, Chaetomium globosum, C. indicum, Cladosporium sp., Curvu-laria lunata, C. tubereulata, Drechslera australiensis, D. hawaiiensis, D. state of Cochliobolus specifer, Fusarium moniliforme, F. oxysporum, F. semitectum, F. solani, Mucor sp., Macrophomina phaseolina, Nigrospora oryzae, Penicillium sp., Paecilomyces variotii, P. lilacinus, Phoma sp., Rhizopus sp., Scopulariopsis sp., Stachybotrys atra, Syncephalastrum sp., and Trichoderma harzianum, atleast 21 species of fungi marked with an asterisk are new reports from tomato seed. Fusarium moniliforme, F. solani, F. oxysporum, A. alternate, D. australiensis, A. flavus and A. niger were found predominant Surface sterilization of seeds showed greater incidence of Chaetomium spp., fusarium oxysporum, F. solani, A. flavus and A. alternate with reduction in infection by A. niger A. terreus, A. wentii, D. australiensis, Penicillium sp., and Rhizopus sp. Where naturally infected seed were sown in steam sterilized soil, C. globisum, F. solani, S. atra, C. herbarum and C. Iunata showed pre-and post emergenece infection of seedling, indicating their seed-borne nature. In pathogenicity test seed inoculation and soil infestation with conidia of F. moniliforme, F. oxysporum and A. alternate reduced seed germination and produced wilting with greater incidence where an increase in inoculum level of the pathogen was used No fruiting was observed where naturally infected seeds were artificially inoculated with F. oxysporum and sown in sterilized soil. Infection by F. oxysporum was also detected from root, stem leaf and flower parts. Soil infested with both Meloidogyne javanica root knot nematode and F. oxysporum showed an increase in gall formatlion only where the population of M. javanica was 2000 eggs/pot and F. oxysporum was 10 cfu/pot, but at high nematode or F. oxysporum population seedling mortality was produced. Paecilomyces lilacinus reduced the infection of M. javanica and F. oxysporum but efficacy of P. lilacinus declined with an increase in inoculum level of the pathogens Seed treatment with Captan or Benlate @ 2 g a.i./kg seed showed significant control of F. oxysporum infection in 60 days old tomato plants in both naturally and artificially infected seeds. Seed dressing with microbial antagonists viz., Paecilomyces lilacinus, Trichoderma harzianum and Rhizobium meliloti also reduced the seed-borne infection of F. oxysporum with better results found in R. meliloti treatment where significant increase in plant height and fresh weight was observed

Item Type:Thesis (PhD)
Uncontrolled Keywords:fungal diseases, tomato, mycoflora, alternaria alternate, a. tenuissima, aspergillus candidus, a. flavus, a. fumigatus, a. niger, a. quadrilineatus, a. flavus, a. niger, a. quadrilineatus, a. sulphureus, a. terreus, a. wentii. aspergillus sp., auriobasidium pullulans, cephaliophora irregularis, chaetomium globosum, c. indicum, cladosporium sp., curvu-laria lunata, c. tubereulata, drechslera australiensis, d. hawaiiensis, d. state of cochliobolus specifer, fusarium moniliforme, f. oxysporum, f. semitectum, f. solani, mucor sp., macrophomina phaseolina, nigrospora oryzae, penicillium sp., paecilomyces variotii, p. lilacinus, phoma sp., rhizopus sp., scopulariopsis sp., stachybotrys atra, syncephalastrum sp., trichoderma harzianum
Subjects:Biological & Medical Sciences (c) > Biological Sciences(c1) > Paleo-botany(c1.9)
ID Code:1216
Deposited By:Mr. Muhammad Asif
Deposited On:04 Jan 2007
Last Modified:04 Oct 2007 21:05

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