ISHS Acta Horticulturae 336: II International Symposium on In Vitro Culture and Horticultural Breeding
LEAF BLIGHT RESISTANCE IN CARROT SOMACLONES |
| Authors: | L.J. Dugdale, H.A. Collin, S. Isaac, J.J.B. Gill |
| Abstract:
One of the major foliar diseases of carrot is leaf blight, caused by the fungus Alternaria dauci. Infection leads to brown necrotic spots on the leaves and a surrounding chlorotic zone. Growers are looking for incrased plant resistance to replace the existing fungicidal seed treatments. One source of resistance is through tissue culture-derived somaclonal variation. In the present project, mature carrot plants have been derived from tissue cultures, and the level of variation examined in these regenerants. Variations observed included differences in leaf structure and shape, and the response to infection. Electron micrographs of infected leaves showed chloroplasts with loss of stroma and membrane damage. Measurement of chlorophyll levels in detached, infected leaves from regenerant plants showed that 21 % had higher chlorophyll levels than the control and 2–3% had two times the highest chlorophyll level of the control. Cytological examination of the regenerant plant roots showed no change in the chromosome number of 2n = 18. Regenerated plants were self-pollinated in preparation fro a progeny analysis of variation in response to infection. | |
Download Adobe Acrobat Reader (free software to read PDF files) | |
