No abstract

Despite the importance of forage quality to animal performance, barley forage quality has not been used as a selection criterion in barley breeding programs. The objectives of this study were to evaluation and QTL analysis of a population of 72 F 1 -derived doubled haploid lines (DHLs) from the cross of 'Steptoe/Morex' for forage quality characteristics. Seventy-two doubled haploid (DH) barley lines and their two parents 'Steptoe' and 'Morex' were planted in a randomized complete block design with two replication at the Research Farm of the University of Tehran, Faculty of Agronomy and Animal Science, Karaj, Iran and Research Farm of the Agricultural Research Station of Zabol, Zabol, Iran. Each plot consisted of four rows that were 3 m in length and spaced 0.25 m apart. Forage sample were collected at dough stage of maturity and dried at 70 • C for 48 hours. Dried samples were ground and scored for eight forage quality characteristics by NIRS. Analysis of variance showed that the main effect of genotype and genotype × environment (location) were significant for all studied traits. The main effect of environment (location) was also significant for all the traits except for ADF. In both environments (Karaj and Zabol) heritability estimates were more than 53.57 for all of the traits. A genetic map comprising 327 molecular markers was recovered from Grain Gene and used for quantitative trait loci (QTL) mapping. This map is fairly saturated with a total length of 1226 cM and an average marker spacing of 3.75 cM. Thirty-two QTLs controlling different studied traits were identified. QTLs were identified for all traits in both environments except ash in Zabol. Total phenotypic variance explained by these QTLs varies from 13.87 to 95.62%. Highest LOD scores were obtained for the CF, ADF and DMD on chromosome 2H and for ash and CP on chromosomes 3H and 5H, respectively. QTLs for DMD and ADF, indicators of digestibility, were found on chromosomes 1H, 2H, 3H, 5H, 6H and 7H. QTLs for NDF an indicator of intake were found on chromosomes 1H, 3H and 5H. QTL analysis is detecting QTLs that varying by location and the specificity of these QTLs for Iranian conditions is discussed.Genetic variation between primary tritipyrum and triticale promising lines, Thinopyrum bessarabicum and wheat cultivars was estimated by random and semi-random primers. Coefficient of genetic similarity ranged from 0.04 to 0.53, which indicated a wide spread genetic variation between lines and cultivars. Minimum genetic similarity (0.04) was observed between 4103 Triticale promising line and wheat St cultivar and maximum genetic similarity (0.53) was observed between 4116 and 4103 of Triticale promising lines. Genetic similarity of primary St/b tritipyrum line (GS = 0.33) in comparison to E b genome was higher than other tritipyrumes. Cluster analysis by means of unweighted pairgroup method showed three major clusters. To detection the presence of E b chromatin in intergeneric hybrids of durum wheat (2n = 2x = 28 AABB genomes) and Thinopyrum bessarabicum (...