Authors:C. Li, X. Ma, A. Wang, E. Nevo and G. Chen
The aerial surface of land plants is protected by a cuticle against abiotic and biotic stresses. A better understanding of the determinants of cuticle formation and function has the potential to contribute to the breeding of more drought tolerant and disease resistant crop varieties. Two doubled haploid (DH) mapping populations, Steptoe × Morex populations and OWB-dominant × recessive populations were exploited to genetically position homologs of a set of known cuticle-associated genes. These genes were also placed on a consensus map, BinMap2005, which includes 27 eceriferum (cer) loci. Of the 49 known cuticle-associated genes, 21 identified a homolog in barley, and of these, 14 were mapped. There was a complete linkage between HvCER6 and cer-zg, suggesting the possibility that HvCER6 is the candidate gene of CER-ZG. Positioning known cuticle-associated genes on a consensus map containing cuticle mutant loci may guide the selection of candidate genes for cuticle mutants, and thus facilitate the isolation of cuticle-associated genes in barley.
Authors:M. Haque, P. Martinek, N. Watanabe and T. Kuboyama
Semi-dwarf varieties in wheat associated with gibberellic acid (GA3)-insensitive height reducing genes have led to significant increases in yield but often fall below this potential because of poor seedling emergence after deep showing. Alternative semi-dwarf genes may have the potential to reduce plant height without compromising early plant growth. In durum wheat, bulk segregant analysis was used to screen microsatellite markers linked with the GA3-sensitive genes Rht14 in cv. Castelporziano, Rht16 in cv. Edmore M1 and Rht18 in cv. Icaro. Molecular marker Xbarc3-6A for Rht14, Rht16 and Rht18 showed significant polymorphic differences among DNA bulks for height classes. The genes Rht14, Rht16 and Rht18 were linked with Xbarc3 (11.7–28.0 cM) on the short arm of chromosome 6A and they appear to be allelic. Semi-dwarf genes on chromosome 6AS may potentially be used in breeding for improved establishment.
Jelen tanulmány elsődleges célja, hogy áttekintse a diszlexia meghatározásának módszertani buktatóit, bemutassa a diszlexia első genetikai vizsgálatait, valamint a géntérképezés elmúlt öt évben született eredményeit. Az utóbbi különösen „forró” téma, mivel számos jelenleg folyó kutatás verseng az első olyan megbízható modell megalkotásában, amely a diszlexia valódi és megbízható genetikai faktorára derít fényt. A géntérképezési vizsgálatok több kromoszómán tíz olyan területet azonosítottak, amelyet DYX területeknek nevezünk. Újabb genetikai vizsgálatok azt is kiderítették, hogy a DYX területeken négy olyan gén található, amely a diszlexiához köthető: DYX1C1 a 15-ös, KIAA0319 és DCDC2 a 6-os, és ROBO1 a 13-as kromoszómán. A funkcionális vizsgálatoknak azt is sikerült kimutatnia, hogy mind a négy gén különleges szerepet játszik az agyfejlődésben, ugyanakkor joggal feltételezhető, hogy ezek a gének és területek csupán egy töredékét képviselik a human lexinomnak. A human lexinom fogalma, amelyet a közelmúltban Gibson és Gruen (2008) vezetett be, magában foglal minden olyan genetikai összetevőt, amely meghatározóan felelős a nyelv és olvasás fejlődéséért.
Authors:B. Kobiljski, S. Dencic, A. Kondic-Spika, U. Lohwasser and A. Börner
The International Triticeae Mapping Initiative (ITMI) recombinant inbred line (RIL) population was used to detect quantitative trait loci (QTL) underlying some key agronomic characters in bread wheat (
L.). Trait measurements were taken from five independent field experiments performed in Serbia. Stable across environment QTL involved in the determination of heading/flowering time and ear morphology/grain yield were detected on, respectively, chromosome arms 2DS and 4AL. These map locations are consistent with those obtained where the same population has been grown in contrasting geographical sites. However, as a result of QTL × environment interactions, not all these QTL are expressed in all environments. Nevertheless the (pleiotropic) effect on ear morphology appears to be expressed in almost all environments, and so represents a high value target for wheat improvement.
Quantitative trait loci (QTL) analysis was carried out with a set of 114 recombinant inbred lines (RILs) from the International Triticeae Mapping Initiative (ITMI) population of ‘W7984’ × ‘Opata 85’ to identify genomic regions controlling traits related to post-anthesis drought tolerance of wheat (
L.). In two experiments performed in Gatersleben in 2001 and 2003, the amount stem reserves mobilisation was estimated by measuring of changes in 1000-grain weight after chemical desiccation treatment. QTLs for stem reserves mobilisation
were mapped on chromosomes 2D, 5D and 7D. The mapping positions obtained in the present investigation are discussed with respect to studies on drought tolerance performed in wheat previously. QTLs for drought tolerance preferentially appeared in homoeologous regions at distal parts of the group 7 chromosomes.
Authors:Karin Huber, Maria Buerstmayr and Hermann Buerstmayr
The aim of the project is the detection, genetic mapping and characterization of quantitative trait loci (QTL) that confer resistance against
head blight in a resistant line of
Authors:V. Pachauri, V. Mishra, P. Mishra, A.K. Singh, S. Singh, R. Singh and N.K. Singh
The present report is in continuation to our earlier reports on the identification and fine mapping of three aroma QTLs in basmati rice using a bi-parental mapping population derived from a cross between Pusa 1121, a basmati rice variety, and Pusa 1342, a non-aromatic rice variety. We used a combination of genetic mapping and transcriptome profiling to narrow down the number of differentially expressed genes in rice to identify potential candidate genes for rice grain aroma. Highly aromatic and non-aromatic recombinant inbred lines (RILs) were identified through sensory analysis of mature milled grains. RILs with similar phenotypes were bulked together using bulk segregant analysis approach which drastically reduced the number of differentially expressed genes from 4016 to 1344. The transcriptome profiles generated were analyzed through Affymetrix rice genome array containing probe sets designed from all the predicted rice gene sequences. Microarray-based transcriptome profiling revealed one down-regulated gene co-located in QTL region aro3.1 on chromosome 3, eight genes co-located in the aro4.1 region on chromosome 4 and the badh2 gene on chromosome 8 to be differentially expressed in the aromatic parent and aromatic bulk. These genes are the most suitable candidates for future validation and development of new molecular functional markers to facilitate marker assisted breeding.