An effective increase in milk production through triticale feeding.

Since the first studies in Algeria in 1999, 2002 and 2005, triticale has been used in arid and semi-arid areas mainly for livestock production. Efforts have been done for the utilization of triticale as hay, silage and hole grain to feed dairy cattle and small ruminants (sheep). Studies have shown that triticale could be easily integrated in the existing crop-livestock system of northern Algeria. In spite of the good results in the yield performance and adaptation to diverse environments, decision makers are not giving the necessary attention to triticale. Dairy cattle holders that tested the crop have adopted it quickly and developed it in an informal way. Now, more than 90% of the triticale seed business is in the hands of private farmers without any help or subsidies nor a good price policy to develop strongly this crop. The utilization of triticale in Algeria is roughly as follow: human consumption 5%, forage crop (hay or silage) 60% and 30% as feed grain, the remaining 5% are kept for sowing seed. In our studies we have compared different feed sources (barley, triticale, concentrate diet and mixtures) to dairy cattle and sheep. Triticale showed highly significantly better results for meat production and gave also an amazing response for dairy and sheep milk production in Algeria. Milk production of animals fed with triticale over exceeded the other feed sources by 26% to 53%; mean weight gain exhibited the same rates.

Mixed model association scans of multi-environmental trial data reveal major loci controlling yield and yield related traits in Hordeum vulgare in Mediterranean environments.

An association panel consisting of 185 accessions representative of the barley germplasm cultivated in the Mediterranean basin was used to localise quantitative trait loci (QTL) controlling grain yield and yield related traits. The germplasm set was genotyped with 1,536 SNP markers and tested for associations with phenotypic data gathered over 2 years for a total of 24 year × location combinations under a broad range of environmental conditions. Analysis of multi-environmental trial (MET) data by fitting a mixed model with kinship estimates detected from two to seven QTL for the major components of yield including 1000 kernel weight, grains per spike and spikes per m(2), as well as heading date, harvest index and plant height. Several of the associations involved SNPs tightly linked to known major genes determining spike morphology in barley (vrs1 and int-c). Similarly, the largest QTL for heading date co-locates with SNPs linked with eam6, a major locus for heading date in barley for autumn sown conditions. Co-localization of several QTL related to yield components traits suggest that major developmental loci may be linked to most of the associations. This study highlights the potential of association genetics to identify genetic variants controlling complex traits.

Patterns of genetic diversity and linkage disequilibrium in a highly structured Hordeum vulgare association-mapping population for the Mediterranean basin.

Population structure and genome-wide linkage disequilibrium (LD) were investigated in 192 Hordeum vulgare accessions providing a comprehensive coverage of past and present barley breeding in the Mediterranean basin, using 50 nuclear microsatellite and 1,130 DArT((R)) markers. Both clustering and principal coordinate analyses clearly sub-divided the sample into five distinct groups centred on key ancestors and regions of origin of the germplasm. For given genetic distances, large variation in LD values was observed, ranging from closely linked markers completely at equilibrium to marker pairs at 50 cM separation still showing significant LD. Mean LD values across the whole population sample decayed below r (2) of 0.15 after 3.2 cM. By assaying 1,130 genome-wide DArT((R)) markers, we demonstrated that, after accounting for population substructure, current genome coverage of 1 marker per 1.5 cM except for chromosome 4H with 1 marker per 3.62 cM is sufficient for whole genome association scans. We show, by identifying associations with powdery mildew that map in genomic regions known to have resistance loci, that associations can be detected in strongly stratified samples provided population structure is effectively controlled in the analysis. The population we describe is, therefore, shown to be a valuable resource, which can be used in basic and applied research in barley.