Trictium aestivum, common wheat, protein content, genetic correlations, environmental correlations . SUMMARYIn a study designed to investigate the nature and basis of the relationships between grain yield (GY) and grain protein concentration (GBC) in common wheat, 11 populations, including 4 homozygous-homogeneous and 7 heterozygous-heterogeneous populations, were evaluated in a space planted and a solid seeded trial . Analysis of yield and protein data from each population revealed that phenotypic and environmental correlations between GY and GPC were negative and highly significant, whereas genetic correlation was significant in only one of 7 segregating populations studied . These results suggested that the inverse relationships between GY and GPC, although phenotypically real, were not caused by genetic factors . It would appear that environmental factors, source-sink interactions, and dilution of protein by non-protein compounds were the major agents that caused undesirable associations between the two traits .

Kibite, S. and Edney, M. J. 1998. The inheritance of ␤-glucan concentration in three oat (Avena sativa L.) crosses. Can. J. Plant Sci. 78: 245-250. Several reports have indicated that oat β-glucans may play an important role in reducing the incidence of degenerative diseases in humans. However, little information has been published on the inheritance of β-glucan concentration in oat. The development of new cultivars with improved β-glucan concentration would be simplified if the mode of inheritance is understood. Three experiments, each using two parental lines and their F 1 , F 2 , F 3 , BC 1 F 2 and BC 2 F 2 generations, were carried out to determine the inheritance of β-glucan concentration. The results indicate that β-glucan concentration is controlled by a minimum of two or three factor pairs with a predominantly additive type of gene action. In the majority of the generations, β-glucan concentration was found to be positively correlated with protein content and negatively correlated with oil content. It was not correlated with grain yield, number of panicles/plant, or number of kernels per panicle. The broad-sense heritability of β-glucan concentration ranged from 0.45 to 0.58 in the F 2 , and from 0.48 to 0.56 in the F 3 generations, suggesting that it may be relatively easy to develop new oat cultivars with high-or low-β-glucan concentration.Key words: Avena sativa, oat, β-glucan concentration, inheritance Kibite, S. et Edney, M. J. 1998. Transmission héréditaire de la concentration de ␤-glucanes dans 3 croisements d'avoine (Avena sativa L.). Can. J. Plant Sci. 78: 245-250. Plusieurs publications ont fait ressortir le rôle important que joueraient les β-glucanes de l'avoine dans la prévention des maladies dégénératives chez les humains, mais avant d'être en mesure de pouvoir créer des nouveaux cultivars plus riches en β-glucanes, nous devons acquérir une meilleure compréhension du mode de transmission héréditaire de ce caractère. Dans ce sens, trois expériences, chacune utilisant 2 lignées parentales et leurs générations F 1 , F 2 , F 3 , RC 1 F 2 et RC 2 F 2 ont été réalisées. Il ressort de nos observations que la concentration de β-glucanes est modulée par au moins 2 ou 3 paires de facteurs, impliquant un type essentiellement additif d'activité génique. Dans la plupart des générations, la concentration de β-glucanes était directement reliée à la teneur en protéine du grain et inversement reliée à sa teneur en huile. Elle ne manifestait pas de corrélation avec le rendement grainier, avec le nombre de panicules par plante, ni avec le nombre de grains par panicule. L'héritabilité au sens large de ce caractère allait de 0,45 à 0,58 dans la F 2 et de 0,48 à 0,56 dans la F 3 , ce qui laisse supposer qu'il serait relativement facile de sélectionner les nouveaux cultivars d'avoine à haute ou à basse teneur en ß-glucanes.

Low hull percentage has long been recognized as a valuable measure of grain quality in oat, Avena sativa L.; however, reliable selection for low hull percentage has been impeded by a lack of understanding of its heritability. The objective of this study was to investigate the heritability of hull percentage in three oat crosses, involving the cultivars Cascade, Robert, and AC Marie, which have 30, 25, and 23% hull, respectively. Populations F2‐deriveF4 through F7 lines were grow in replicated or unreplicated trials at several locations in western Canada from 1992 to 1995. Heritability estimates were calculated based on hull percentage data determined by mechanically dehulling 2‐g kernel mixtures or samples of 50 primary kernels. Primary kernel hull percentage data, collected from replicated trials at multiple locations, were used to evaluate the effect of genotype × location interaction on phenotype. Broad‐sense heritability estimates by parent‐offspring regression ranged from 0.35 to 0.72 for hull percentage of 2‐g kernel mixtures, and 0.80 to 0.90 for hull percentage of 50 primary kernels. An evaluation of variance components showed highly significant genotype and location effects for primary kernel hull percentage. Genotype effects had a greater influence than location on primary kernel hull percentage, whereas the effect of genotype × location interaction was relatively less important. High broad‐sense heritability estimates for hull percentage support the use of early generation selection for reduced hull content in oat.

The degree of aluminium tolerance varies widely across cereal species, with oats (Avena spp.) being among the most tolerant. The objective of this study was to identify molecular markers linked to aluminium tolerance in the diploid oat A. strigosa. Restriction fragment length polymorphism markers were tested in regions where comparative mapping indicated the potential for orthologous quantitative trait loci (QTL) for aluminium tolerance in other grass species. Amplified fragment length polymorphism (AFLP) and sequence-characterized amplified region (SCAR) markers were used to provide additional coverage of the genome. Four QTL were identified. The largest QTL explained 39% of the variation and is possibly orthologous to the major gene found in the Triticeae as well as Alm1 in maize and a minor gene in rice. A second QTL may be orthologous to the Alm2 gene in maize. Two other QTL were associated with anonymous markers. Together, these QTL accounted for 55% of the variation. A SCAR marker linked to the major QTL identified in this study could be used to introgress the aluminium tolerance trait from A. strigosa into cultivated oat germplasm.

Kibite, S. and Taylor, J. S. 1994. Inheritance and linkage relationships of genes conditioning hullessness, multiflorous spikelet' and giantism inoat(Avena sativaL.\. Can. J. Plant Sci. 74:497-500. A study was conducted to determine the number of g.n.r, typ" of gene action, and linkage relationships of the factors controlling the expression of hullessness, multiflorous spikelet and giantism in oat (Avena sativaL. var. PI 546363). The results showed that giantism was governed by a recessive gene' which in a homozygous (gi-ilgi--l) condition may have an epistatic effect on several other loci including those controlling the expression of plant treiglt; tength, width, and thickness of leaves; culm diameter; number of internodes; panicle size; pedicle length; and number of days to anthesis and to maturity. The results also indicated monogenic inheritance for hull and spikelet characteristics.Hullessness (N-I I _) was dominant over hullednes s (n-I I n-t) , and multiflorous spikelet (Mf-I I -) was panially dominant over normal spikelet(mf-Ilmf-t). Linkage was detected between the gi-3 locus controlling giantism, and the n-1 locus controlling hullessness; the recombination value was calculated to be 36.5 + O.8Vo. Linkage was also detected between the gi-3 gene and the Mf-I locus conditioning multiflorous spikelet; the recombination value was 23.5 + 0.4%. The N-1 gene appears to have an epistatic effect on the uj-l locus, and the recombination frequency between the two loci was 10.5 ! 0.6%. The gene order was gi-3, Mf-L, N-l.