| Autor: |
Harris-Shultz KR; 1 United States Department of Agriculture-Agricultural Research Service (USDA-ARS), Crop Genetics and Breeding Research Unit, 115 Coastal Way, Tifton, GA 31793., Davis RF; 2 USDA-ARS, Crop Protection and Management Research Unit, 2747 Davis Road, BLDG 1, Tifton, GA 31794., Wallace J; 3 Department of Crop & Soil Sciences, University of Georgia, 111 Riverbend Road, Athens 30602., Knoll JE; 1 United States Department of Agriculture-Agricultural Research Service (USDA-ARS), Crop Genetics and Breeding Research Unit, 115 Coastal Way, Tifton, GA 31793., Wang H; 4 USDA-ARS, Hard Winter Wheat Genetics Research, 4007 Throckmorton Hall, Manhattan, KS 66506. |
| Abstrakt: |
Southern root-knot nematodes, Meloidogyne incognita , feed on the underground portions of hundreds of plant species and affect nutrient partitioning and water uptake of the host plants. Sorghum ( Sorghum bicolor ) is often not significantly damaged by southern root-knot nematodes (RKN) but some sorghum genotypes support greater population densities of RKN than other genotypes. These higher nematode populations increase the risk of damage to subsequently planted susceptible crops. A previous study identified a major quantitative trait locus (QTL) for RKN resistance on sorghum chromosome (chr.) 3. To maintain long-term resistance, multiple resistance genes should be pyramided in a cultivar. In this study, we identified a new source of RKN resistance, created a mapping population, and identified single-nucleotide polymorphism markers using genotyping-by-sequencing of the segregating population. Use of single-marker analysis and composite interval mapping identified a single QTL on chr. 5 that was associated with egg number and egg number per gram of root from the resistant sweet sorghum line PI 144134. This region on chr. 5 and the prior QTL on chr. 3 can be potentially moved from PI 144134 and Honey Drip, respectively, into elite sorghum germplasm via marker-assisted selection for more durable resistance. |
