ISHS Acta Horticulturae 459: International Symposium Brassica 97, Xth Crucifer Genetics Workshop
VARIATION FOR POD SHATTER RESISTANCE IN B. NAPUS |
| Authors: | C.L. Morgan, Z. Ladbrooke, A.E. Arthur, D. Bruce, R. Child |
| Keywords: | Dehiscence zone, Genetic variation, Oil-seed rape, Pod walls, Synthetic B. napus |
| Abstract:
Pods which show significantly improved resistance to shattering have been identified among a range of 35 resynthesised doubled haploid B. napus lines selected from three families derived from different diploid parents (B. oleracea ssp atlantica, macrocarpa and alboglabra). A method has been developed which provides a reliable laboratory measurement of the energy needed to cause the fracture of the dehiscence zone in mature pods of each line. Measurements of the physical forces needed to cause premature dehiscence, together with scanning electron micrographs (SEMs) of the fractured surface of the dehiscence zone, have been made for all these lines. Additional measurements have been made on plant morphological characters, such as height and stem width, and raceme characteristics including density of pods on the raceme, pod length and width, and pod and pedicel angles. The significant genetic variation observed for pod shattering, and also found for these other characters, is dependent on the diploid origin of the resynthesised B. napus. Correlations among the characters show that the three groups i.e. the assessors of pod shatter resistance, plant morphology and raceme morphology, are broadly independent of each other which suggests that it should be possible to introduce pod shattering resistance into oilseed rape without compromising other important agronomic characters. The detailed investigations (SEM) of the dehiscence zone have revealed differences in the cell and vascular structure of the dehiscence zone amongst the lines. Pods which are resistant to shatter show a smooth fracture face with many torn cells in contrast to that of shattering sensitive lines which show a loose assemblage of largely unbroken cells. | |
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