Czech Journal of Genetics and Plant Breeding - In Press
Evaluating the discriminatory ability and informativeness of DArTseq markers in a comprehensive set of contemporary European potato varietiesOriginal Paper
Petr Sedlák, Vladimíra Sedláková, Jakub Vašek, Ervín Hausvater, Daniela Čílová, Martina Melounová, Jiří Ptáček, Petr Doležal
High-throughput molecular technology DArTseq generates markers for potential use in molecular breeding of crops. Using DArTseq, we analysed a comprehensive set of 333 European potato varieties reflecting the outcomes of long-term breeding history and representing a potential germplasm for future breeding of potatoes in the Central European region. The varieties were classified according to four factors: region of origin, breeder, earliness and utilisation mode, that may potentially reflect their genetic structure, and for which complete data were publicly available. The DArTseq analysis was performed by service centre the Diversity Array Technology (University of Canberra), which generated approximately 38 000 silicoDArT and 64 000 SNP (single nucleotide polymorphism) polymorphic markers. The discriminatory ability of the markers in relation to the factors was confirmed using neighbour-joining and principal coordinate analysis (PCoA), while the informativeness was assessed using the discriminant analysis of principal components (DAPC). The analyses identified the 50 SNPs most strongly associated with each factor, along with their highly probable chromosomal localisation. Herein presented research contributes to the evaluation of potato genetic resources by adding the novel molecular data of active germplasm and implies their future utilisation in genome wide association studies and marker assisted selection.
Identification of wheat leaf rust resistance genes and utilization value analysis of leaf rust resistance genes in 42 wheat cultivarsOriginal Paper
Xue Li, Zhanhai Kang, Jiaqi Zhang, Sufen Dong, Man Li, Xing Li
Leaf rust is an important wheat disease that is a significant hindrance for wheat production in most areas of the world. Through the identification of leaf rust resistance genes of 42 wheat varieties, the materials with durable disease resistance were screened out, providing effective source materials for wheat disease resistance breeding. In this study, 42 wheat cultivars were inoculated with 18 strains of Puccinia triticina Eriks in the seedling stage to postulate the Lr gene in the cultivars and germplasms. Resistance to leaf rust of these cultivars at the adult plant stage was tested in fields under natural infection during the 2019 to 2020 cropping seasons in Baoding Hebei Province. The gene postulation integrated with molecular marker detection showed that ten Lr genes (Lr1, Lr10, Lr14a, Lr26, Lr2a, Lr17, Lr20, Lr34, Lr37 and Lr46) were identified in 42 wheat accessions. Among the 42 wheat accessions postulated with Lr genes, Lr1 was present in 16 accessions, Lr14a in 3 accessions, Lr17 in 5 accessions, Lr2a in 5 accessions, Lr34 in one accessions, Lr10 in two accessions, Lr37 in two accessions and Lr46 in 29 accessions. In the collection of 42 cultivars/germplasms, 15 wheat lines displayed adult-plant resistance or underdetermined genes. Therefore, a high level of leaf rust resistance can be achieved through the combination of all-stage resistance and adult-plant resistance genes together in wheat cultivars.
Expression plasticity of VRN-1 homoeologs in hexaploid wheat under field conditionsOriginal Paper
Nicole Frantová, Ilja Tom Prášil, Ludmila Holková
Flowering time determines wheat adaptation and yield stability, yet field evidence on the plasticity of VRN-1 homoeolog expression is limited. We quantified VRN-1 homoeolog dynamics across two sites and two seasons in seven cultivars, sampling apex and leaf. VRN-A1 varied with genotype (P < 0.001***), tissue (apex > leaf; P < 0.001***), apex development (P < 0.001***), day length (P < 0.001***), and recent freezing had a smaller effect (P = 0.019*). Photoperiod class (Ppd-D1a vs ppd-D1b) added an additional effect (P = 0.001***). VRN-B1 showed strong genotype effects (P < 0.001***), a site effect (P = 0.025*), and pronounced microclimate associations (day length, thermal sums, freezing load all P < 0.001***). Directionally, Ppd-D1a backgrounds tended to advance development while showing the earlier apex VRN-A1 peaks. We conclude that VRN-A1 might track developmental stage and seasonal forcing, whereas VRN-B1 might be more microclimate-responsive, indicating complementary roles for timing and stress-response plasticity. To isolate causal effects and further explain these dynamics, targeted sequencing and tests in near-isogenic lines will be needed in future work.