The detection of QTLs controlling bacterial wilt resistance in tobacco (N. tabacum L.)

• Published in: Euphytica Vol. 192; no. 2; pp. 259 - 266
• Main Authors: Qian, Yi-liang, Wang, Xin-sheng, Wang, Da-zhou, Zhang, Li-na, Zu, Chao-long, Gao, Zheng-liang, Zhang, Hong-jun, Wang, Zhi-yong, Sun, Xue-yong, Yao, Da-nian
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer Netherlands 01.07.2013; Springer
• Subjects: Agronomy. Soil science and plant productions; Bacteria; Biological and medical sciences; Biomedical and Life Sciences; Biotechnology; Classical and quantitative genetics. Population genetics. Molecular genetics; Fundamental and applied biological sciences. Psychology; Generalities. Genetics. Plant material; Genetics and breeding of economic plants; Life Sciences; Molecular genetics; Plant Genetics and Genomics; Plant Pathology; Plant Physiology; Plant Sciences; Quantitative genetics; Ralstonia solanacearum; Varietal selection. Specialized plant breeding, plant breeding aims; Quantitative trait loci; Tobacco; SSR; Bacterial wilt resistance; Stimulant plant; Nicotiana tabacum; Infection; Resistance; Dicotyledones; Microsatellite DNA; Angiospermae; Genetic improvement; Bacteriosis; Spermatophyta; Solanaceae
• ISSN: 0014-2336; 1573-5060
• DOI: 10.1007/s10681-012-0846-2

The bacterial tobacco wilt caused by Ralstonia solanacearum is one of the most destructive soil-borne diseases worldwide. One strategy to improve the resistance to bacterial wilt is to make use of plant varieties expressing wilt resistance genes. To characterize the genetics of wilt resistance and to identify relevant molecular markers for use in plant breeding, quantitative trait loci (QTLs) affecting tobacco bacterial wilt resistance were mapped in the F 2:3 and F 2:4 progeny produced from two crosses between the wilt-resistant breeding lines Enshu and Yanyan97 and the susceptible cultivar TI448A. A linkage map containing 118 loci in 24 linkage groups was constructed for 236 lines from the Enshu×TI448A cross, and a linkage map containing 96 loci in 24 linkage groups was constructed for 264 lines from the Yanyan97×TI448A cross. The wilt resistance of the progeny was examined in field trials conducted in Xuancheng, China, in 2010, 2011, and 2012. The disease severity was assessed on stems using separate rating scales. Mapmaker/EXP 3.0 and Mapmaker/QTL 1.1 were used to identify the qBWR - 3a, qBWR - 3b, qBWR - 5a and qBWR - 5b QTLs in linkage group 3 and 5; these four loci were strongly associated with resistance and explain 9.00, 19.70, 17.30, and 17.40 % of the variance in resistance, respectively. The close linkage of the markers PT20275 and PT30229 was detected in both the TI448A×Enshu and TI448A×Yanyan97 crosses, and this linkage group could be used to select individual resistant plants. These findings suggest that one strategy to combat bacterial wilt could be to exploit the resistance genes of the Enshu and Yanyan97 strains.