Ancestral germplasm may be a useful source of genetic variation for crop improvement. Genetic variation in developmental traits that contribute to heading date may be useful in developing varieties that are uniquely tailored to specific stress environments. Hordeum vulgare subsp. spontaneum (K. Koch) A. & Gr. is the ancestor of cultivated barley and useful developmental trait alleles may have been lost in the domestication process. Accordingly, we surveyed a sample of 16 subsp. spontaneum accessions for vernalization requirement, photoperiod sensitivity, photoperiod response, and relative earliness. We compared the subsp. spontaneum accessions to four H. vulgare L. subsp. vulgare accessions representing spring, facultative, and winter growth habit. Thirteen subsp. spontaneum accessions originating from the Fertile Crescent and the one subsp. spontaneum accession from the Caucasus region required vernalization; they were responsive to long photoperiods and most were very early. Two subsp. spontaneum accessions from the Himalayan region had no vernalization requirement but were extremely sensitive to short photoperiods. We used a clustering procedure to define two groups of subsp. spontaneum accessions, a group of subsp. spontaneum that included the two subsp. vulgare accessions of spring and facultative growth habit, and a fourth group comprised of the two subsp. vulgare winter habit cultivars. These data indicate that subsp. spontaneum may be a source of novel alleles for growth habit.

To determine the effect of Vrn-H2 locus on plant developmental and agronomic traits, detailed controlled environment tests involving a factorial set of vernalization and photoperiod treatments were carried out using doubled haploid lines developed from a facultative (Vrn-H2 ) ) · winter (Vrn-H2 + ) barley cross. The allele phase at the Vrn-H2 locus influenced heading date as well as the developmental and agronomic traits. The performance of Vrn-H2 + lines was significantly influenced by vernalization: reproductive fitness traits showed significant decreases without vernalization. However, the effects of alleles at the Vrn-H2 locus extended beyond simple satisfaction of the vernalization requirement. Vrn-H2 + lines showed increased reproductive fitness compared with Vrn-H2 ) lines when vernalization was followed by a long photoperiod. The responses of the two Vrn-H2 allele classes to photoperiod duration were quite different in terms of heading date, developmental and agronomic traits. These results suggest that alleles at the Vrn-H2 locus -and/or tightly linked gene(s) -respond primarily to the exogenous signal of vernalization (temperature), but when the vernalization requirement has been fulfilled, they also respond to photoperiod duration.

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Spelt wheat [Triticum aestivum ssp. spelta (L.) Thell.] is becoming a valuable crop due to its reputation as a healthy food. In Australia, this crop has not been targeted for systematic breeding. Identification of spelt genotypes having low PPO activity and resistance to acid soils (Al 3+ ) are desirable attributes for future cultivar development. We evaluated 51 genebank accessions of spelts from the Australian Winter Cereals Collection for polyphenol oxidase (PPO) activity and for resistance to aluminium (Al). PPO activity was measured both visually and spectrophotometrically, using L-DOPA substrate. PPO activity for genotypes ranged from 0.15 to 1.3 and could be grouped into 'low', 'medium' and 'high' categories. At least eight accessions exhibited low PPO activity (not different to the durum check cultivar Arrivato). After measuring PPO activity, the same kernels were further evaluated for Al resistance using a nutrient solution culture method with haematoxylin staining test of root tips. Thirty-three accessions were resistant to Al. Functional gene markers associated with loci conditioning Al resistance gene (TaALMT1) and PPO activity (XPPO-2A) in common wheat confirmed their association with target phenotypes within spelt accessions. Genetic variation within spelt wheat for important agronomic and quality traits such as Al resistance and PPO suggested that progress in spelt improvement can be made by molecular plant breeding. Diversity Array Technology (DArT) based allelic data revealed that these spelt accessions are genetically diverse.