Induction of resistance to the root-knot nematode, Meloidogyne hapla, with other Meloidogyne species, on tomato and pyrethrum plants.

Persistent Link:
http://hdl.handle.net/10150/187065
Title:
Induction of resistance to the root-knot nematode, Meloidogyne hapla, with other Meloidogyne species, on tomato and pyrethrum plants.
Author:
Ogallo, Leopold Juma
Issue Date:
1995
Publisher:
The University of Arizona.
Rights:
Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.
Abstract:
Resistance to the root-knot nematode, Meloidogyne hapla, was systemically induced on tomato and pyrethrum plants by advance inoculations with mildly virulent M. incognita and M. javanica, respectively. The reproduction of M. hapla was reduced by 84% on tomato (var. Celebrity), and by 72% on pyrethrum (clone 223) in greenhouse experiments, and by 55% on pyrethrum plants on field-plot experiments, relative to the non-induced controls. The magnitude of induced resistance increased with increasing intervals between the applications of resistance inducer and challenge nematode inocula, from 0 to 10 day intervals, then levelled off, for both tomato and pyrethrum. Induced resistance increased also with increasing levels of inducer inoculum, from 0 to 5,000 infective juveniles per plant in 500 ml pots, for both tomato and pyrethrum. Advance inoculation of one halves of partially-split root systems with resistance-inducing nematodes resulted in protection of the other halves from challenge nematodes. The observation indicated the systemic translocation of induced resistance factors from sites of induction to remote plant parts. Advance inoculations of host plants with the virulent M. hapla increased susceptibility in the plants to secondary nematode inocula, such that the originally non-virulent M. incognita and M. javanica subsequently attained enhanced reproduction rates comparable to M. hapla. Pyrethrum seedlings which received advance inoculation with M. javanica prior to challenge with M. hapla had growth rates comparable to those of nematode-free controls, while the unprotected M. hapla-infected plants were stunted up to 33%, in greenhouse experiments. In field plot experiments, the unprotected pyrethrum seedlings were stunted up to 36%, relative to plants with induced resistance. These results suggest that initial incompatible or compatible plant-nematode interactions conditioned the plants to increased resistance or susceptibility, respectively, against subsequent invading nematodes. As such, advance inoculations of plants with incompatible or mildly virulent nematodes, could be a prospective method of protecting plants against virulent nematodes.
Type:
text; Dissertation-Reproduction (electronic)
Degree Name:
Ph.D.
Degree Level:
doctoral
Degree Program:
Plant Pathology; Graduate College
Degree Grantor:
University of Arizona
Committee Chair:
McClure, Michael Antony

Full metadata record

DC FieldValue Language
dc.language.isoenen_US
dc.titleInduction of resistance to the root-knot nematode, Meloidogyne hapla, with other Meloidogyne species, on tomato and pyrethrum plants.en_US
dc.creatorOgallo, Leopold Jumaen_US
dc.contributor.authorOgallo, Leopold Jumaen_US
dc.date.issued1995en_US
dc.publisherThe University of Arizona.en_US
dc.rightsCopyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.en_US
dc.description.abstractResistance to the root-knot nematode, Meloidogyne hapla, was systemically induced on tomato and pyrethrum plants by advance inoculations with mildly virulent M. incognita and M. javanica, respectively. The reproduction of M. hapla was reduced by 84% on tomato (var. Celebrity), and by 72% on pyrethrum (clone 223) in greenhouse experiments, and by 55% on pyrethrum plants on field-plot experiments, relative to the non-induced controls. The magnitude of induced resistance increased with increasing intervals between the applications of resistance inducer and challenge nematode inocula, from 0 to 10 day intervals, then levelled off, for both tomato and pyrethrum. Induced resistance increased also with increasing levels of inducer inoculum, from 0 to 5,000 infective juveniles per plant in 500 ml pots, for both tomato and pyrethrum. Advance inoculation of one halves of partially-split root systems with resistance-inducing nematodes resulted in protection of the other halves from challenge nematodes. The observation indicated the systemic translocation of induced resistance factors from sites of induction to remote plant parts. Advance inoculations of host plants with the virulent M. hapla increased susceptibility in the plants to secondary nematode inocula, such that the originally non-virulent M. incognita and M. javanica subsequently attained enhanced reproduction rates comparable to M. hapla. Pyrethrum seedlings which received advance inoculation with M. javanica prior to challenge with M. hapla had growth rates comparable to those of nematode-free controls, while the unprotected M. hapla-infected plants were stunted up to 33%, in greenhouse experiments. In field plot experiments, the unprotected pyrethrum seedlings were stunted up to 36%, relative to plants with induced resistance. These results suggest that initial incompatible or compatible plant-nematode interactions conditioned the plants to increased resistance or susceptibility, respectively, against subsequent invading nematodes. As such, advance inoculations of plants with incompatible or mildly virulent nematodes, could be a prospective method of protecting plants against virulent nematodes.en_US
dc.description.noteDigitization Note: p.61 missing from paper original and microfilm version.-
dc.typetexten_US
dc.typeDissertation-Reproduction (electronic)en_US
thesis.degree.namePh.D.en_US
thesis.degree.leveldoctoralen_US
thesis.degree.disciplinePlant Pathologyen_US
thesis.degree.disciplineGraduate Collegeen_US
thesis.degree.grantorUniversity of Arizonaen_US
dc.contributor.chairMcClure, Michael Antonyen_US
dc.contributor.committeememberNelson, Merritt R.en_US
dc.contributor.committeememberMisaghi, Iraj J.en_US
dc.contributor.committeememberWatson, Theo F.en_US
dc.contributor.committeememberAleamoni, Lawrence M.en_US
dc.identifier.proquest9531088en_US
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