Show simple item record

dc.contributor.authorStewart, Alan V.
dc.date.accessioned2007-10-04T22:13:33Z
dc.date.available2007-10-04T22:13:33Z
dc.date.issued1987
dc.identifier.urihttps://hdl.handle.net/10182/136
dc.description.abstractSome aspects of the presence of systemic endophytic fungi in agriculturally important New Zealand grasses were studied in relation to plant breeding. Seedling resistance to adult Argentine stem weevil feeding in perennial ryegrass, Italian ryegrass and tall fescue was found to be related to the presence of their respective Acremonium endophytes in the seed rather than to plant genetic resistance. In addition a study of perennial ryegrass revealed that this resistance was independent of endophyte viability. The seedling resistance conferred by the endophyte of Italian ryegrass was found to be beneficial for field establishment. This endophyte differs from that in perennial ryegrass and tall fescue in that it does not confer resistance to Argentine stem weevil on mature plants, but only on seedlings. The extent of plant genetic seedling tolerance to adult Argentine stem weevil feeding was limited to broad inter-specific differences, with tall fescue more tolerant than perennial ryegrass and both of these more tolerant than Italian ryegrass. This ranking corresponds with previous observations on feeding preference on mature plants. A study of factors affecting the concentration of endophyte mycelia in infected seed of perennial ryegrass revealed that plant genetic factors had little effect. The major factors studied were: 1) the endophyte concentration in the maternal parent plant directly influenced the endophyte concentration in the seed. 2) nitrogen fertilizer applications to a seed crop reduced the concentration of mycelia in the seed, with earlier applications having a greater effect. 3) application of the fungicide propiconazole (Tilt) to a seed crop reduced the endophyte concentration in the seed. 4) the endophyte concentration in the seed was found to directly influence the endophyte concentration in seedlings, six month old plants and that of seed harvested from a first year seed crop. As there have been no previous reports of tetraploid perennial ryegrass cultivars with endophyte an experiment was conducted to determine if these could be developed by the standard procedure of colchicine treatment. The results revealed that endophyte was retained following colchicine treatment.en
dc.language.isoenen
dc.publisherLincoln College, University of Canterburyen
dc.rights.urihttps://researcharchive.lincoln.ac.nz/page/rights
dc.subjectryegrassen
dc.subjectLoliumen
dc.subjectendophyteen
dc.subjectAcremoniumen
dc.subjectseedling resistanceen
dc.subjectnitrogenen
dc.subjectfungicidesen
dc.subjecttetraploiden
dc.subjectArgentine stem weevilen
dc.subjectListronotusen
dc.titlePlant breeding aspects of ryegrasses (Lolium sp.) infected with endophytic fungien
dc.typeThesisen
thesis.degree.grantorUniversity of Canterburyen
thesis.degree.levelDoctoralen
thesis.degree.nameDoctor of Philosophyen
dc.subject.marsdenFields of Research::300000 Agricultural, Veterinary and Environmental Sciences::300200 Crop and Pasture Production::300203 Plant improvement (selection, breeding and genetic engineering)en
lu.thesis.supervisorFautrier, Aldo
lu.thesis.supervisorSmetham, Michael
lu.contributor.unitAgriculture Groupen


Files in this item

Default Thumbnail
Default Thumbnail

This item appears in the following Collection(s)

Show simple item record