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Foliar Resistance (foliar + resistance)

Distribution by Scientific Domains

Life Sciences	100%

Selected Abstracts

Foliar and tuber late blight resistance in a Solanum tuberosum breeding population

PLANT BREEDING, Issue 2 2010
H. Mayton
With 2 figures and 2 tables Abstract The purpose of this research was to identify the genetic basis of foliar and tuber resistance to Phytophthora infestans in a potato breeding population developed from a cross between two tetraploid Solanum tuberosum lines, NY121 and NY115. The parent with high foliar resistance, NY121, was highly susceptible to tuber blight. Foliar resistance was assessed in field trials, while tuber blight was assessed both in the field and in the laboratory. A quantitative trait locus (QTL) explaining ca. 50% of the phenotypic variance for foliar resistance was located on the lower arm of linkage group V, and was loosely associated with tuber blight resistance (significantly in one of two trials). This QTL was confirmed in a separate sample from the same population. Tuber blight detected via laboratory assays was not correlated with tuber blight incidence in the field. Most markers associated with tuber blight resistance were not associated with foliar resistance and most markers associated with foliar resistance were not associated with tuber blight resistance. [source]

Mapping polygenes for tuber resistance to late blight in a diploid Solanum phureja × S. stenotomum hybrid population

PLANT BREEDING, Issue 4 2006
I. Simko
Abstract Potato tuber blight is a disease caused by the oomycete Phytophthora infestans (Mont.) de Bary. Due to the significant economic impact of this disease, introgression of durable resistance into the cultivated potato is one of the top priorities of breeding programmes worldwide. Though numerous resistance loci against this devastating disease have already been mapped, most of the detected loci are contributing towards foliar resistance while specific information on tuber resistance is limited. To identify the genetic components of tuber resistance and its relationship to foliar resistance and plant maturity we have investigated the host-pathogen interaction in a segregating diploid hybrid Solanum phureja × S. stenotomum family. Mature tubers from this mapping family were inoculated with a sporangial suspension of P. infestans (US-8 clonal lineage) and evaluated for lesion expansion. No significant correlation was detected between late blight resistance in foliage and tubers, and between plant maturity and tuber resistance. Four chromosomal regions were significantly associated with tuber resistance to the disease. The largest effect was detected near the marker locus PSC (LOD 10.7) located on chromosome 10. This locus explained about 63% of the total phenotypic variation of the trait. The other three resistance-related loci were mapped on chromosomes 8 (GP1282, LOD 4.4), 6 (CP18, LOD 4.0) and 2 (CP157, LOD 3.8). None of the four tuber resistance loci coincides with the foliage resistance loci detected in this same family. Tuber blight resistance quantitative trait loci (QTL) on chromosomes 2, 8 and 10 are distinct from the maturity QTLs and have an additive effect on tuber resistance. These results indicate that different genes are involved in foliar and tuber resistance to P. infestans in the present family and that some of the resistance genes might be associated with late maturity. [source]

Evaluation of foliar resistance in potato to Phytophthora infestans based on an international field trial network

PLANT PATHOLOGY, Issue 2 2005
J. G. Hansen
During the period 2000,03, local potato cultivars in Estonia, Latvia, Lithuania, Poland and Denmark were tested for foliar resistance to Phytophthora infestans (late blight) in an international field trial network. Four standard cultivars were included in the trials: Sava, Oleva, Danva and Kuras. Primary disease-assessment data were entered into a common database, and parameters from the disease progress curves were calculated and made available on interactive web pages. A regression model, using relative area under disease progress curve (RAUDPC) values for cv. Oleva as a reference, was developed for the estimation of 1,9 scale values, where 1 = most susceptible. Standard deviations for the estimated 1,9 scale values and a nonparametric rank stability analysis of RAUDPC were used to evaluate the stability of resistance of the cultivars. Overall, the results showed stability of resistance for cvs Sava, Oleva and Danva, but not for Kuras. Use of the Internet-based Web-Blight service in this study facilitated comparison of results among countries for the level and stability of resistance. The estimated 1,9 scale values were similar to, or slightly lower than, those from official cultivar lists or from the European Cultivated Potato Database, especially for the more resistant cultivars. Possible reasons for discrepancies from different sources and locations are discussed. It is concluded that RAUPDC and the derived 1,9 scale values are useful for ranking cultivars for resistance to P. infestans, but this information is not detailed enough for use in a decision support system for late blight control. [source]