@article{vontimitta_lewis_2012, title={Growth Chamber Evaluation of a Tobacco 'Beinhart 1000' x 'Hicks' Mapping Population for Quantitative Trait Loci Affecting Resistance to Multiple Races of Phytophthora nicotianae}, volume={52}, ISSN={["1435-0653"]}, DOI={10.2135/cropsci2011.06.0303}, abstractNote={Multiple races of Phytophthora nicotianae (van Breda de Haan) cause the black shank disease of tobacco (Nicotiana tabacum L.). Identifi cation of novel alleles affecting resistance and associated DNA markers might help increase the range and level of cultivar resistance. A doubled haploid mapping population generated from a highly resistant × susceptible cross (‘Beinhart 1000’ × ‘Hicks’) was evaluated for resistance after inoculation with either race 0 or race 1 in a growth chamber and also genotyped at 206 microsatellite marker loci. Multiple interval mapping identifi ed two major genomic regions affecting resistance to both races. A quantitative trait locus (QTL) on linkage group 8 explained 54.7 and 45.5% of the observed variation for end percent survival after race 0 and race 1 inoculation, respectively. A QTL on linkage group 4 explained a larger proportion (16.8%) of phenotypic variation for race 1 resistance as compared to race 0 resistance (1.8%). In combination with previously reported fi eld data, the study authenticates the role of these two regions on black shank resistance. Correlations of line performance under fi eld and growth chamber environments were good, and agreement was excellent at extreme levels of resistance or susceptibility. With appropriate isolate selection, growth chamber inoculations may provide a superior alternative to fi eld evaluations for mapping QTL affecting black shank resistance. Identifi ed QTL and associated markers may be useful for increasing levels of resistance to P. nicotianae in tobacco cultivars.}, number={1}, journal={CROP SCIENCE}, author={Vontimitta, V. and Lewis, R. S.}, year={2012}, month={Jan}, pages={91–98} } @article{vontimitta_lewis_2012, title={Mapping of quantitative trait loci affecting resistance to Phytophthora nicotianae in tobacco (Nicotiana tabacum L.) line Beinhart-1000}, volume={29}, ISSN={["1572-9788"]}, DOI={10.1007/s11032-010-9528-8}, number={1}, journal={MOLECULAR BREEDING}, author={Vontimitta, Vijay and Lewis, Ramsey S.}, year={2012}, month={Jan}, pages={89–98} } @article{vontimitta_danehower_steede_moon_lewis_2010, title={Analysis of a Nicotiana tabacum L. Genomic Region Controlling Two Leaf Surface Chemistry Traits}, volume={58}, ISSN={["1520-5118"]}, DOI={10.1021/jf903256h}, abstractNote={cis-Abienol and sucrose esters are Nicotiana tabacum leaf surface components that likely influence plant resistance to pests. Their breakdown products also contribute to flavor and aroma characteristics of certain tobacco types. Mapping of genes involved in the biosynthesis of these compounds could permit development of molecular-based tools for generating tobacco types with novel cured leaf chemistry profiles. A doubled haploid mapping population segregating for major genes (Abl and BMVSE) affecting the ability to accumulate cis-abienol and sucrose esters was generated and genotyped with a large set of microsatellite markers. The two genes were found to reside on chromosome A of the N. tabacum genome with a distance of 8.2 cM (centimorgans) between them. Seventeen microsatellite markers were also placed on this linkage group, several of which exhibited complete cosegregation with Abl and BMVSE. Results should aid breeding efforts focused on modification of this aspect of tobacco cured leaf chemistry.}, number={1}, journal={JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY}, author={Vontimitta, Vijay and Danehower, David A. and Steede, Tyler and Moon, Hyunsook S. and Lewis, Ramsey S.}, year={2010}, month={Jan}, pages={294–300} }