Segments taken from the basal 15 to 20 millimeters of the two innermost leaves of an orchardgrass (Dactylis glomerata L.) genotype produced somatic (nonzygotic) embryos directly from mesophyll cells without an intervening callus when cultured on an agar medium with 30 micromolar 3,6-dichloro-o-anisic acid (dicamba). This demonstration of high-frequency embryogenesis from mesophyll cells in Gramineae is strong evidence for totipotency of the cells.

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Breeding for malting quality is an important goal of malting barley breeding programs. Malting quality is a complex phenotype that combines a large number of interrelated components, each of which shows complex inheritance. Currently, only a few genes involved in determining malting quality have been characterized. We combined transcript proWling with phenotypic correlations to identify candidate genes for malting quality. The Barley1 GeneChip ® array containing 22,792 probe sets was used to conduct transcript proWling of genes expressed in several diVerent stages of malting of four malting cultivars. Genes that were diVerentially expressed in comparisons between diVerent malting stages relative to ungerminated seed, as well as in comparisons between malting cultivars in the same malting stage were identiWed. Correlation analysis of 723 diVerentially expressed genes with malting quality phenotypes showed that 11-102 of these genes correlated with six malting quality phenotypes. Genes involved in carbohydrate metabolism were among the positively correlated genes. Genes for protein and lipid metabolism, cell wall organization and biogenesis, and genes involved in stress and defense response also correlated with malting quality phenotypes. Expressed sequence tags (ESTs) were generated from a 'malting-gene enriched' cDNA library made by suppression subtractive hybridization between malted and ungerminated seeds of 'Morex'. Eleven percent of the ESTs had no signiWcant homology with sequences in the databases, suggesting that there may be other malting-related genes Communicated by A. Graner. Electronic supplementary materialThe online version of this article

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The purpose of this investigation was to demonstrate callus induction and plantlet formation from cultured leaf segments of 12-15 week-old Dactylis glomerata L. (orchardgrass) plants. Flat half-leaf sections, approximately 2-3 mm square, from the three innermost (youngest) leaves were isolated and individually plated serially beginning at the leaf base on a solid SH medium containing 30 μM of 3,6-dichloro-oanisic acid (dicamba). Callus formed on leaf sections from all 50 plants used in the study. After transfer to SH medium with 1 μM dicamba, plantlets formed from leaf sections of 9 of the 50 plants. In most cases plantlets formed from embryogenic callus but in a few cases embryoids formed directly on the leaf surface without an intervening callus state. These developed into plantlets when transferred to low auxin medium. The response for both callus and plantlet formation decreased with increasing distance both spatially and temporally from the shoot apex. Histological examination of embryogenic callus revealed the presence of non-zygotic embryos in various stages of development. The results provide further support for compentency (if not totipotency) of Gramineae leaf cells.