Authors:P. Martins-Lopes, B. Maças, and H. Guedes-Pinto
Guedes-Pinto, H., Pinto-Carnide, O., Igrejas, G., Nascimento, M., Carnide, V.P., Heslop-Harrison, J.S., Gateau, I., Branlard, G. 1998. Studies of Barbela wheat, an old Portuguese landrace with rye introgression. In: Lelley, T. (ed.), Current Topics in
.E., Ambrose, M.& Reader, S.M. (2001): The Watkins collection of land-race derived wheats. -in: Caligari, P.D.S. & Brandham, P.E. (Eds) Wheat Taxonomy: the Legacy of John Percival . The Linnean Special Issue, No. 3. Academic Press, pp. 113
Authors:S. Šliková, M. Havrlentová, P. Hauptvogel, Ľ. Mendel, E. Gregová, and V. Šudyová
Winter wheat landraces and modern Slovak cultivars were inoculated with the pathogen Fusarium culmorum Sacc. by spraying in May 2008, in plot experiments under natural conditions in Piešťany, Slovakia. The objective was to examine the responses of the tested genotypes to inoculation with F. culmorum and to determine changes in the β-D-glucan content in the kernels. The area under the disease progress curve (AUDPC), Fusarium-damaged kernels (FDK) and the β-D-glucan and deoxynivalenol (DON) contents in the grains were determined using Megazyme and Ridascreen® Fast DON assay kits. Wheat landraces had lower AUDPC and FDK, and accumulated 67.4% less DON than modern cultivars. There were highly significant correlations (P < 0.01) between AUDPC and DON content, between FDK and DON, and between AUDPC and FDK. The correlation between β-D-glucan content and AUDPC was also significant (P < 0.05), but not correlations between β-D-glucan and other traits. The β-D-glucan content in the grain of wheat genotypes artificially inoculated with F. culmorum was lower than in grains without infection. The wheat landraces contained more β-D-glucan than modern cultivars and showed higher resistance to F. culmorum. The three wheat landraces had significantly lower spike and kernel infection compared to modern cultivars and could be used to breed elite cultivars with enhanced Fusarium head blight resistance.
Authors:A. Etminan, A. Pour-Aboughadareh, R. Mohammadi, A. Noori, and A. Ahmadi-Rad
Progress in plant molecular tools has been resulted in the development of gene-targeted and functional marker systems. CAAT box region is a different pattern of nucleotides with a consensus sequence, GGCCAATCT, which situated upstream of the start codon of eukaryote genes and plays an important role during transcription. In the present study, several CAAT box-derived polymorphism (CBDP) primers were used for fingerprinting in mini-core collection of durum wheat (including internationally developed breeding lines and Iranian landraces). Twelve selected primers amplified 98 loci, of which all were polymorphic. The average values of the polymorphism information content (PIC) and resolving power (Rp) were 0.31 and 9.16, respectively, indicating a high level of variability among studied genotypes. Analysis of molecular variance (AMOVA) indicated that 92% of the total variation resided among populations. The values of the percentage polymorphic bands (PPL), the observed (Na) and effective (Ne) number of alleles, Nei’s gene diversity (He) and Shannon’s information index (I) for Iranian landraces were higher than the breeding lines. The Fandendrogram obtained by cluster analysis grouped all individuals into three main clusters. Our results showed a remarkable level of genetic diversity among studied durum wheat, especially among Iranian landraces, which can be interest for future breeding programs. More importantly, the present study also revealed that CBDP technique was efficient and powerful tool to assess genetic diversity in wheat germplasm. Hence, this technique could be employed individually or in combination with other molecular markers to evaluate genetic diversity and relations among different species.
Authors:J.Q. Xu, L. Wang, B.L. Liu, T.F. Xia, D.C. Liu, X. Chang, T.W. Zhang, H.G. Zhang, and Y.H. Shen
As one of the world’s earliest domesticated crops, barley is a model species for the study of evolution and domestication. Domestication is an evolutionary process whereby a population adapts, through selection; to new environments created by human cultivation. We describe the genome-scanning of molecular diversity to assess the evolution of barley in the Tibetan Plateau. We used 667 Diversity Arrays Technology (DArT) markers to genotype 185 barley landraces and wild barley accessions from the Tibetan Plateau. Genetic diversity in wild barley was greater than in landraces at both genome and chromosome levels, except for chromosome 3H. Landraces and wild barley accessions were clearly differentiated genetically, but a limited degree of introgression was still evident. Significant differences in diversity between barley subspecies at the chromosome level were observed for genes known to be related to physiological and phenotypical traits, disease resistance, abiotic stress tolerance, malting quality and agronomic traits. Selection on the genome of six-rowed naked barley has shown clear multiple targets related to both its specific end-use and the extreme environment in Tibet. Our data provide a platform to identify the genes and genetic mechanisms that underlie phenotypic changes, and provide lists of candidate domestication genes for modified breeding strategies.
Authors:J. Díaz De León, R. Escoppinichi, R. Zavala-Fonseca, T. Castellanos, M. Röder, and A. Mujeeb-Kazi
To determine limits of tolerance, provide information about genetic diversity, and explore potential as progenitors for a salt-tolerant wheat improvement program, we collected several landraces and genotypes reputed to be salt-tolerant. Salt tolerance was tested by irrigation with a diluted solution of seawater with 12 dS.m
electrical conductivity for two years. Phenotypic parameters of percent of emergence, days to flowering to spike emergence, and physiological maturity were not significantly affected. Leaf area was sensitive to salt stress and inhibited about 30%. Plant height was inhibited 30%, while spike length and number of grains per spike were not. Total yield of Shorawaki and Kharchia landraces confirmed their reputation as salt-tolerant. Cultivars Mepuchi, Pericu, Calafia, WH157, and SNH-1 were inhibited at a moderate level of tolerance; cultivars Cochimí, Lu26S, and KRL 1–4 were inhibited, as was the control cultivar Oasis by up to 50%. To amplify microsatellites from genomes A, B, and D, 33 pairs of primers were used. The microsatellite WMS169-6A was highly polymorphic, with 10 different alleles distinguishing the genotype set. Also, the short arm of chromosome 4D microsatellites were amplified and found to be monomorphic, which suggests highly conserved alleles. The other microsatellites had variable polymorphism. In total, 120 alleles were obtained and used to define genetic diversity. The resulting dendrogram showed that landraces Shorawaki and Kharchia are distantly grouped from all other cultivars, as well as the cultivar Chinese Spring. Strikingly, KRL1–4, a derivative of Kharchia, did not show a close relationship to its source. The geographic origin did not influence pair-wise combinations. However, pedigree did influence pair-wise combinations.