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1973 - 197912000 - 20051

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    Transformations of grapevine pathogens Eutypa lata and Phaeomoniella chlamydospora : a one year project thesis presented in partial fulfilment of the requirements for the degree of Master of Science in Genetics at Massey University, Palmerston North, New Zealand
    (Massey University, 2005) Duan, Guowen
    A transformation system has been developed for the grapevine pathogenic fungi Eutypa lata and Phaeomoniella chlamydospora using a positive selection system based on the Escherichia coli hygromycin B phosphotransferase gene (hph). The system developed could give large, stable transformants at frequencies between 0.7 and 6.5 transformants per µg of DNA. A second type of colony also grew on the selective media. These were believed to be abortive transformants. The first type of transformants were characterized using classical molecular biological technologies such as PCR and Southern hybridization, and the transformation was shown to be successful. Plasmids (pBCH-gfp and pCT74) containing a gfp reporter gene were also transformed into these two fungal species. Expression of the gfp gene was checked using a fluorescence microscope and gfp-expressing E. lata transformants were inoculated onto the host plants blackcurrant and grapevine. Confocal observation of the movement of fungal mycelia in wood tissues was performed but its interaction with host plant was not established in the time available. Purified gfp-expressing P. chlamydospora transformants were also obtained. A vector containing a fragment of the P. chlamydospora putative toxin gene moxY was constructed and transformed into P. chlamydospora. Putative moxY gene disruption transformants were screened with PCR followed by Southern hybridization. The putative moxY gene disruption transformants were spore purified and further confirmed with Southern hybridization. Whilst both PCR and Southern hybridization confirmed disruption of the moxY gene, clear evidence for the presence of an additional wild type moxY was also seen in the same transformants. This led to the suggestions that either P. chlamydospora is a natural diploid, or that moxY is essential for growth and that selective pressures led to the formation of a wild type: moxY-hph diploid.
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    Flower blight of chrysanthemums : the causal fungi and their control : a thesis presented in partial fulfilment of the requirements for the degree of Master of Agricultural Science at Massey University
    (Massey University, 1973) Singh, Gurmit
    The commercial chrysanthemum commonly grown in New Zealand is botanically identified as Chrysanthemum morifoliurr. Ramat. and is believed to have originated in China. As the family name Compositae suggests the individual flower ('flower head') is a composite arrangement of two types of florets, namely ray florets with well developed petals, and disc florets with tubular or poorly developed petals. Production of commercial chrysanthemums basically comprises three categories: (i) cut flowers; (ii) cuttings; (iii) container or pot plants. Chrysanthemums are probably grown by more floriculturalists than any other flower crop. Much of its popularity is attributed to the wide range of colours and forms and the fact that it can be grown either as a pot plant or for cut flowers. Another important characteristic of the chrysanthemum is the long keeping quality of the flowers, a feature which is much appreciated by retailers and consumers. In the United States of America the chrysanthemum or 'mum' is the most popular flower, surpassing both the rose and carnation in total wholesale value. [FROM INTRODUCTION]