Download or read book Studies on the Etiology of the Leaf Blotch Disease of Eucalyptus Spp Caused by Mycosphaerella Nubilosa Cke Hansf written by Alhagananthan Ganapathi and published by . This book was released on 1979 with total page 276 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Mycosphaerella Species Causing Leaf Blotch on Eucalyptus Species in South Africa written by Gavin Craig Hunter and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Studies presented in this thesis, highlight the complexity and importance of Mycosphaerella leaf disease (MLD) on Eucalyptus spp., especially in South Africa. In Chapter I, a review of the literature dealing with Mycosphaerella and MLD of Eucalyptus spp. is presented. It is clear from this review that the disease is prevalent in most countries where Eucalyptus spp. are commercially grown, including Australia where they are native. The number of Mycosphaerella species known from Eucalyptus spp. is increasing and this suggests that their economic effect on commercial Eucalyptus forestry, will probably Increase. It will thus become important to effectively identifY species responsible for MLD. To do this, the existing complex taxonomy of this group of fungi, will undoubtedly prove to be an obstacle. However, DNA based identification methods are proving useful in identifying species and delimiting lineages within Mycosphaerella. Future commercial propagation of Eucalyptus spp. will need to seriously consider the use of hybrids resistant to infection by Mycosphaerella spp. Furthermore, there will be a serious need for effective quarantine measures to prevent the introduction of new, perhaps more pathogenic, Mycosphaerella spp. into areas where they do not already occur. Three species of Mycosphaerella, M. molleriana, M.M. nubilosa and M. juvenis have traditionally been regarded as the most important Mycosphaerella spp. in South Africa. At various times, each species has been considered to be the only pathogen causing MLD in the country. Results from Chapter 2 and Chapter 3 have shown that M. nubilosa is the main pathogen responsible for MLD, especially, on E. nitens in the KwaZulu-Natal province of South Africa. This is interesting as M. molleriana, which was originally thought to be the only species in South Africa, was not isolated. Moreover, the susceptibility of E. nitens to M. nubilosa appears to be high, resulting in severe defoliation. Considering that E. nitens is a popular species grown at higher altitudes of South Africa, the recognition of M. nubilosa is important. This fungus is well recognized in Australia as an important pathogen and comparisons of data from that country will be useful in the future. Several Mycosphaerella spp. have, in the past been found to occur within single stands of commercial Eucalyptus spp. As part of the research presented in Chapter 3, surveys conducted in South Africa showed that there are seven species of Mycosphaerella occurring in plantations. These include: M. ellipsoidea, M. irregulariramosa, M. juvenis, M. lateralis, M. marksii, M. nubilosa and one newly described species M. fori. All of these species, apart from M. fori, were previously known to occur in South Africa. It is interesting that M. juvenis, previously thought to be one of the main species causing MLD, was found only to occur in a low numbers. This suggests that species causing epidemics may change over time. The identification of M. fori from a previously well surveyed area was unexpected. This new species was dominant in Tzaneen and future surveys will be conducted to determine its distribution and host range within South Afiica. The identification of a new species also highlights the need for additional surveys in South Africa to identify new species and to recognize possible new introductions of exotic Mycosphaerella spp. The presence of M. ellipsoidea, M. irregulariramosa, M. lateralis and M. marksii in this survey was not unusual, as they were previously known in South Africa. However, they were found only to occur at low levels and, as such, do not seem to contribute significantly to outbreaks of MLD. Various taxonomic and DNA-based methods have been used for the identification of Mycosphaerella spp. However, some taxonomic characters are of little value at the species level. In Chapter 4, RFLP's were considered as an option to differentiate between species of Mycosphaerella on Eucalyptus. Results of this study showed that the restriction enzyme HaeIII may be used for RFLP identification of Mycosphaerella spp. From a total of twenty-one Mycosphaerella spp. tested, RFLP digestion with HaeIII could resolve six of these species to species level. However, other species formed groups that had similar restriction profiles. They could be further separated based on ascospore germination patterns. This study forms a foundation for future studies in which other enzymes may be used together with HaeIIi to elucidate groups of species. It is suggested though, that this technique be combined with existing methods such as ascospore germination patterns and anamorph associations to identify species of Mycosphaerella occurring on Eucalyptus spp. with confidence. This should negate the use of expensive sequencing techniques, which are currently necessary. In virtually every country where Eucalyptus is grown commercially, MLD is prevalent. However, the specific Mycosphaerella spp. in countries are generally not the same. In Chapter 5, I used DNA sequence data from the ITS region of the rDNA operon as well as morphological data to identify M. heimii from Brazil and Hawaii, U.S.A. This represents the first report of the species from these countries. M heimii was previously thought to occur only in Madagascar and Indonesia, where it is recognized as a primary pathogen of several Eucalyptus spp, including E. urophylla. This is one of the main Eucalyptusspp. in Brazil. It has thus been suggested that this species may have been introduced into these countries via infected seed lots. This highlights the need for effective quarantine measures within these and other South American countries to inhibit the further spread of this pathogen through South America. Copyright.
Download or read book Diseases and Pathogens of Eucalypts written by PJ Keane and published by CSIRO PUBLISHING. This book was released on 2000-10-25 with total page 576 pages. Available in PDF, EPUB and Kindle. Book excerpt: Over the last fifty years, there has been an increasing recognition that eucalypts are vulnerable to a wide range of diseases. They have suffered destructive epidemics, particularly of dieback caused by the cinnamon fungus in native forests, of foliar diseases and cankers in plantations, and of dieback of remnant trees on agricultural and grazing land. This has stimulated intensive research into the causes and management of diseases of the eucalypts. This work represents a comprehensive review of our current knowledge of the health and diseases of eucalypts.
Download or read book Mycosphaerella Spp and Their Anamorphs Associated with Leaf Spot Diseases of Eucalyptus written by Pedro W. Crous and published by American Phytopathological Society. This book was released on 1998 with total page 180 pages. Available in PDF, EPUB and Kindle. Book excerpt: This monograph covers 57 species of Mycosphaerella, including six new species. A discussion of disease assessment, provenance selection and general epidemiology is combined with an evaluation of the value of taxonomic features such as symptomatology, teleomorph and anamorph characters.Features of the book include symptom photographs and illustrations of Mycosphaerella spp. and their anamorphs that help with disease identification, and standardized methods that aid in studying species of Mycosphaerella spp.This comprehensive monograph will be an asset to mycologists, plant pathologists, forest pathologists, foresters, and extension agents in the field or laboratory, as a source of complete up-to-date research on Mycosphaerella spp. and their anamorphs.
Download or read book Canadian Journal of Forest Research written by and published by . This book was released on 1994 with total page 796 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Aerobiology and Epidemiology of Mycosphaerella Nubilosa Cke Hansf on Eucalyptus Spp written by Lian-Heng Cheah and published by . This book was released on 1977 with total page 71 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Mycosphaerella Nubilosa Cke Hansf on Eucalyptus Delegatensis R T Baker written by Robert Marshall Beresford and published by . This book was released on 1978 with total page 264 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Fertilisation and Forest Health written by and published by . This book was released on 2006 with total page 150 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Australian Forestry written by and published by . This book was released on 2002 with total page 606 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Cryptogamie written by and published by . This book was released on 1988 with total page 408 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Diseases and Pathogens of Eucalypts written by P. J. Keane and published by CSIRO PUBLISHING. This book was released on 2000 with total page 618 pages. Available in PDF, EPUB and Kindle. Book excerpt: A comprehensive review of our current knowledge of the health and diseases of eucalypts.
Download or read book Cultivation and diseases of Proteaceae Leucadendron Leucospermum and Protea written by Pedro Willem Crous and published by . This book was released on 2013 with total page 360 pages. Available in PDF, EPUB and Kindle. Book excerpt:
