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Constructions of the Linkage Genetic Map and QTL Mapping for the Resistance to Stripe Rust in Forage Triticale (×Triticosecale) |
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Abstract In order to construct the genetic linkage map of triticale (×Triticosecale) and locate the quantitative trait locus (QTL) resistant to the stripe rust disease in triticale, F2 generation derived from triticale cross was used as the mapping population and fourteen inter-simple sequence repeats (ISSR) primers were used to amplify the F2 generation. One genetic linkage map was constructed using the Joinmap 4.0 software and QTLs related to the resistance of stripe rust was located in triticale. Main results were as follows, a) the linage map included 7 linkage groups (named LG1 ~ LG7), the total length of map was 542.9 cM, the averaged distance among markers was 5.90 cM, and there were 92 loci. b) For 184 plants of F2 population, the resistance and susceptibility to the rust disease changed continuously and the distribution frequency was nearly normal. Therefore, it was suitable to be used to locate the QTLs related to the resistance of stripe rust in triticale. c) QTL results showed that there were 6 QTLs (QDR1, QDR3, QDR4, QDR5-1, QDR5-2, QDR6) related to the resistance of stripe rust in triticale by using MapQTL6.0 software while the threshold was LOD≥2.0. Six QTLs distributed on the linkage groups of LG1, LG3, LG4, LG5 and LG6. The contribution rate of QTLs resistant to the stripe rust varied from 5.1% to 11.2%. Among 6 QTLs, QDR5-1 was the main QTL resistant to stripe rust and the additive effect varied from -0.18 to 0.27. The QTLs located in this study will provide theoretical basis for the cloning, transformation, utilization of the genes resistant to the stripe rust in triticale, and elevating the efficiency to breed new triticale varieties resistant to stripe rust disease.
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Received: 20 January 2017
Published: 25 March 2018
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