Two-row Feed Research Articles

Spring Barley Resistance and Tolerance to the Cereal Cyst Nematode Heterodera avenae.

Heterodera avenae is a cereal cyst nematode that reduces wheat yields in the Pacific Northwest of the United States. Barley is also susceptible but there were no previous reports of resistance or tolerance to H. avenae in the United States. Spring barley cultivars were assayed in H. avenae-infested fields over 2 years. Cultivars were planted in plots treated or not treated with aldicarb. Forty-five cultivars were evaluated for the market classes of two- and six-row feed barley cultivars and two- and six-row malt barley cultivars. One two-row feed barley ('Lenetah') was ranked as resistant and four were tolerant or very tolerant. In total, 1 two-row malt barley ('Odyssey') was very resistant and 10 were tolerant or very tolerant. Two six-row feed and two six-row malt barley cultivars were tolerant or very tolerant but none were resistant. Seven feed barley cultivars were ranked as having a balance of at least moderate resistance plus moderate tolerance: 'Champion', Lenetah, 'Xena', 'Idagold II', 'Transit', 'Millennium', and 'Goldeneye'. This is the first report of resistance and tolerance of barley in H. avenae-infested fields in the Pacific Northwest. Barley productivity can be improved by planting resistant plus tolerant cultivars or by using highly resistant and highly tolerant cultivars as parents in barley improvement programs.

An investigation of the feasibility of predicting nitrogen-corrected true metabolizable energy (TMEn) content in barley from chemical composition and physical characteristics

A study utilizing 91 barley samples was conducted to investigate the feasibility of predicting the nitrogen-corrected true metabolizable energy (TMEn) value of barley for poultry. The samples included three barley types (six-row malting and feed and two-row feed) that were grown at 12 different locations in Manitoba from 1986 to 1988. Substantial variation in chemical and physical measurements was evident among the barley samples studied, and data indicated TMEn of 13.10–14.59 with a mean of 13.97 (MJ kg−1 on dry matter). It was found that TMEn was negatively correlated with neutral detergent fibre (NDF) level (r = −0.784) and positively correlated with test weight (r = 0.627). Significant relationships also existed between TMEn and contents of starch and fat, but only 7–8% of the variation in TMEn was accounted for by those variables. Inclusion of NDF, gross energy (GE), fat, protein and starch terms in a multiple-regression equation resulted in a slight decrease in residual standard deviation and an increase in R2. The best combinations of predictor variables were, in decreasing order, NDF, GE and fat selected from stepwise regression and NDF, fat and starch selected from the Mallows Cp values. With the exception of the equation using test weight as sole predictor, the errors estimated from the simple- (NDF as sole predictor), multiple- and stepwise-regression equations or the equation selected according to the Mallows Cp value were similar to the error approached for the biological measure, TMEn. Key words: Rooster, barley, nitrogen-corrected true metabolizable energy, prediction

Bridge two-row feed barley

Bridge is a two-rowed, hulled, spring feed barley suitable for growing in the western part of the Canadian prairies. It has a combination of high yield potential, high test weight and large kernels. Bridge was developed from a backcross involving TR 521 (Zephyr/Hector) as the cytoplasm donor and recurrent pollen parent, and TR 516 (Betzes/Piroline *2//Zephyr). Key words: Hordeum vulgare L., barley (two-rowed spring feed)

A partial map of the barley genome incorporating restriction fragment length polymorphism, polymerase chain reaction, isozyme, and morphological marker loci

Nine low copy number genomic DNA clones, a ribosomal sequence, and seven cDNA clones were found to identify polymorphisms in cultivated barley (Hordeum vulgare L.). An F2 population consisting of 100 plants was produced from a cross between a high-yielding two-rowed feed barley cultivar and a genetic marker stock homozygous for nine recessive and one dominant morphological marker genes. Through the use of these 10 well-distributed marker genes, five previously mapped isozyme loci, and two storage-protein loci, the approximate recombinational location for each of 17 restriction fragment length polymorphism loci was estimated. One clone, pMSU21, identified variation that appeared to be the result of a small insertion-deletion event that differentiated two-rowed and six-rowed genotypes. This difference was characterized, and one allele was sequenced. Oligonucleotide primers that flanked the insertion-deletion event were synthesized, and DNA samples from the F2 population were subjected to polymerase chain reaction sequence amplification. The variation identified by this technique was determined to be allelic to the variation identified using pMSU21 in Southern blot analysis. Maps of previously undescribed informative clones are included.