| Fusarium head blight (FHB) of Barley is a serious disease of barley production, widely distributed in each big barley production area of the world. Fusarium is the main pathogenic species of FHB and can infect during barley flowering period and cause reduction of production and concentration of toxins mainly of DON in barley. Diseased barleycorn can directly affects grain processing and nutritional quality:when used to make wine, diseased barleycorn can cause beer gushing; when used for eating or feeding, it will be harmful for human and animal.Cultivation measures such as plowing, ditching, drainage, rational fertilization, and non-host crop rotation can limit the spread of FHB, but its efforts have met with limited success. The spraying of pesticides can effectively combat the barley scab incidence, but chemical control not only increase costs, but also inevitably, pollutes the environment. Applying of resistant cultivars is the most economical, effective and environmental control method of FHB.Three types of FHB resistance have been described in barley:penetration, spread and mycotoxin degradation. In order to improve the efficiency of breeding, researchers have identified barley resources of with different inoculation method. They have already researched with molecular markers in two-rowed and two-rowed groups, six-rowed and six-rowed groups, and two-rowed and six-rowed groups. Through the analysis of the eight resistant parents(Chevron (Switzerland)、Gobernadora (Mexico)、Fredrickson(Japan)、 Zhedar2 (China)、Russia 6 (Russian)、CIho4196 (China)、Harbin 2-row (China)、 Zhenongda 7(China)),13 genetic groups, they have initially positioned the 95 penetration resistance QTLs,3 spread resistance QTLs,31 QTLs for resistance to DON concerntration. At present, chromosome location of barley FHB spread resistance QTLs is limited, and the effect is not obvious.As identification of FHB resistance resources, Two-rowed Barley Scab resistance was significantly better than six-rowed Barley, it was positively correlated between prism and barley FHB resistance. Therefore, In this study, in order to avoid the affect of the prism of barley to chromosome location of FHB Resistance, parental RIL genetic groups were constructed with 2 two-rowed barley resistant sources and two-rowed barley susceptible varieties.This research try to locate barley FHB Resistance QTL with resistance identification, to lay the foundation for the cultivation of excellent FHB scalability barley varieties.Epil is two-rowed barley variety breeded by Hubei Province Academy of Agricultural Sciences, Yan96157 is two-rowed barley variety breeded by Jiangsu coastal region agricultural scientific research institute, as identification of Jiangsu Academy of Agricultural Biotechnology Research Institute, FHB resistance is good and stability. In this research, we used two-rowed barley FHB susceptible varieties of Meilihuangjin/FHB resistant varieties Epil to construct RILs, and we selected 198 materials of F8 as our experiment materials. What’s more, we also utilized FHB susceptible varieties of Ganpi2/ resistant varieties Yan96157 to construct RILs, and selected 108 materials of F6 as experiment materials. In order to perform the FHB phenotype identification, we used the single flower drop injection method, and we selected the percentage of scabbed spikelets (PSS) after inoculated with 21 day and area under disease progress curve (AUDPC) as evaluation index of FHB resistance to scalability. To perform genotype identification for two groups respectively, we used SSR, STS and SNP molecular marker methods. Genetic linkage map was constructed with Joinmap4.0, and then we used composite interval mapping method of WinQTLCart2.5 to make QTL analysis. The main results were as follows:1. Percentage of Scabbed Spikelets (PSS) and Area Under Disease Progress Curve (AUDPC) were analyzed in the population Meilihuangjin/Epil and Ganpi 2/Yan96157 respectively. The analysis revealed that PSS and AUDPC 21d after inoculation showed larger separation and continuous variation, which means Barley Scab scalability is a quantitative trait controlled by multiple genes. PSS and AUDPC were the evaluation index of FHB resistance to scalability, and they had a very significant negative correlation, the correlation coefficient is 0.9434.2. Genetic linkage map of two groups were built:Genetic linkage map of Meilihuangjin/Epil and Genetic linkage map of Ganpi2/Yan96157. Genetic linkage map of Meilihuangjin/Epil, which included 69 markers, spanned 578.6cM. There are 10 markers on every chromosome on average, the distance of two markers is 8.39cM on average and the minimum distance of two markers is 0.8cM. Genetic linkage map of Ganpi2/Yan96157 had 65 markers, which spanned 600.1cM. The are 9 markers on every chromosome on average, the average distance of two markers is 9.23cM and the minimum distance is 0.4cM.3. With the method of composite interval mapping to perform QTL analyze of the two groups. in Meilihuangjin/Epil,the analysis of PSS after inoculated with 21 day showed that, a FHB resistant scalability QTL (Qfhb-3-4) was found, which was located on the barley 3H, between EBmac0853-120 and Bmag0603, and the confidence interval was 17.51cM 23.01cM, LOD value was 3.50, and it can be explained 14.99% of phenotypic variation, the additive effect was -3.01, indicated this QTL beneficial allele is from the parent Epi1;The QTL analysis of AUDPC showed that:a QTL(Qaudpc-3-3) associating with FHB resistant was found,which was located on 3H,between Bmag0905 and EBmac0853-120, the confidence interval was 12.10cM～21.01cM, LOD value was 3.22, and it can be explained 15.88% of phenotypic variation, the additive effect was -2.01, indicated this QTL beneficial allele is from the parent Epil; In Ganpi2/Yan96157, Two QTLs of Barley FHB extension (Qfhb-5-11, Qfhb-6-6) were detected with PSS after inoculated with 21d, which are located on the barley 5H and 6H. Qfhb-5-11 was located between scssr10148 and Bmag0222, confidence interval was 109.82cM～113.01cM, LOD value was 2.11, which can be explained the phenotypic variation of 8.85%, the additive effect was -4.72, indicating that this QTL beneficial allele is from the parent Yan96157. Qfhb-6-6 is located between the marker Bmag0496-200 and Bmag0496-420, the confidence interval was 10.71cM 28.51cM, LOD value was 3.90, which can be explained the phenotypic variation of 30.15%, the additive effect was 6.27, indicating that this QTL favorable alleles is from parents Ganpi2; The QTL analysis of AUDPC showed that:two QTLs(Qaudpc-5-11, Qaudpc-6-6) associating with FHB resistant was found,which werelocated on 5H,6H,and were included in Qfhb-5-11, Qfhb-6-6 respectively. Qaudpc-5-11 was between scssr10148 and Bmag0222, confidence interval was 109.31cM～112.01cM, LOD value was 2.07, which can be explained the phenotypic variation of 8.89%, the additive effect was -21.42, indicating that this QTL beneficial allele is from the parent Yan96157.Qfhb-6-6 was located between Bmag0496-200 and Bmag0496-420, the confidence interval was 12.71cM～26.51cM, LOD value was 3.65, which can be explained the phenotypic variation of 14.78%, the additive effect was 27.93, indicating that this QTL favorable alleles is from parents Ganpi2.In this article, we employed QTLs analysis for FHB resistance of spread. As a result, we obtained 6 QTLs, Qfhb-3-4, Qfhb-5-11, Qfhb-6-6, Qaudpc-3-3, Qaudpc-5-11 and Qaudpc-6-6, which related to FHB resistance. We also have cleared their location in chromosomes, confidence interval, contribution rate and resistance sources, which can be used as a reference in barley FHB resistance breeding in the future. |
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