The heritability of resistance to early blight in diploid potatoes (Solanum tuberosum, subsp.Phureja andStenotomum)
The heritability of resistance to early blight caused byAlternaria solani (Ell. & Martin) Son was estimated for field grown, diploid potatoes at Fletcher, North Carolina in 1981. Fourteen breeding lines, selected from a random mated hybrid population ofSolanum tuberosum, subsp.phureja andstenotomum, were used. Resistance was measured as the slope obtained by regressing the logit of the disease proportion Y, measured as % defoliation, on time. A wide range of resistance was found. Narrow-sense heritability, as determined by offspring-midparent regression, on an individual plant basis, was calculated to be 0.825.
Phenotyping early blight resistance in potato cultivars and breeding clones
Thirty-two potato cultivars/clones were evaluated for resistance to early blight using different methods. The evaluations were performed under field and greenhouse conditions. In the field experiments, plants were evaluated for disease symptoms, and the relative area under the disease progress curve and percent defoliation were determined. In the greenhouse experiments, leaf lesion sizes were determined on either intact plants or detached leaves after drop inoculation with Alternaria solani. The effect of leaf position (lower, middle or upper part of the plant) on lesion size was investigated. There was no correlation between lesion sizes on lower leaves and upper leaves after inoculation. However, significant correlations between lesion sizes on lower and middle leaves and also between middle and upper leaves were found. Furthermore, we found significant correlation between the results of resistance studies in the field and in intact plant inoculation experiments in the greenhouse. In contrast, results from the detached-leaf experiment were not correlated with either greenhouse intact plant tests or field results. The results indicate that using detached-leaf assays for screening potato for early blight resistance is not accurate. We found significant differences in resistance to A. solani among cultivars/clones in both the field and in greenhouse experiments.
Appropriated Pasts: Indigenous Peoples and the Colonial Culture of Archaeology
Chapter 1 Colonial Culture of Archaeology Chapter 2 Progressivism: The Invention of Prehistory Chapter 3 Antiquation: Aboriginal Peoples as Living Fossils Chapter 4 Migrationism: The Archaeology of Dispossession Chapter 5 Diffusionism: The Archaeology of Alienation Chapter 6 Subjectation: Appropration Through Science Chapter 7 Shared Nations: The New Appropriation Chapter 8 Partnerships: Pathways to a Decolonised Practice Chapter 9 References Chapter 10 Index