Submitted to: Rice Technical Working Group Meeting Proceedings
Publication Type: Proceedings
Publication Acceptance Date: January 15, 2010
Publication Date: February 22, 2010
Citation: Wang, Y., Roberts, P.N., Fjellstrom, R.G., Tabien, R.E. 2010. Breeding Value of the qSB9b and qSB12a QTLs in RiceBreeding Value of the qSB9b and qSB12a QTLs in Rice. Rice Technical Working Group Meeting Proceedings, Biloxi, MS, Feb. 22-25, 2010. CDROM. Technical Abstract: Sheath blight (SB) caused by Rhizoctonia solani Kuhn is a serious rice disease worldwide. The results of 123 TeQing-into-Lemont (TILs) showed those with introgressions containing qSB9b and/or qSB12a were among the most SB resistant TILs. TIL:615, TIL:642 and TIL:567 have consistently appeared moderately-resistant in field plots, and it was determined using molecular markers that they contain the qSB9b and/or qSB12a QTLs. To accurately evaluate the phenotypic resistance effect conferred by qSB9b and qSB12a, TIL:615, TIL:642 and TIL:567 had been crossed with Lemont. F2 individuals which contained pure Lemont alleles versus TeQing (resistant) alleles for qSB9b and qSB12a were selected based on molecular markers saturated in the two QTL regions, with data being used to construct F2:3 families. The resistance of F2:3 families to the sheath blight pathogen Rhizoctonia solani were identified using a micro-chamber screening method in greenhouse at Beaumont AgriLife Research & Exctension Center, TX. The preparatory results showed that qSB9b and qSB12a were dominant resistance QTLs. The results provide useful information for rice breeding. Strong resistant varieties/lines can be obtained by marker-assisted selection (MAS) method.