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The research program is primarily centering on spike and spikelet development in wheat and barley. 

        I.             Inflorescence Architecture of Cereal Spikes:  Our understanding of the molecular genetics of spike or spikelet development is very limited in small grain cereals. Functional knowledge of genes, which regulate key developmental traits such as inflorescence branching, spikelet initiation or abortion, rachis internode length, or total number of rachis internodes is almost completely lacking in most of our cereal crops. We are utilizing natural spike variants from wheat and induced spike mutants from barley to clarify the genetic make-up of genes underlying developmental phenotypes for reduced and increased grain number per spike.

 

 

      II.             Flowering Time affects Spike Development:  Optimal adaptation to a given environment and subsequently high yield potential is mainly determined by the time of flowering. Time to flowering, however, is commonly affected by a complex interplay between three determinants: photoperiodic and vernalization requirements as well as the intrinsic capability of a cultivar/genotype to flower. The intrinsic capability to flower early is also called “earliness per se”. We are studying an early-heading mutant from diploid einkorn wheat, Triticum monococcum L., which possesses a single major recessive earliness per se (eps) locus on the very distal end of the long arm of chromosome 3AL. Frequently, eps loci are associated with reduced spikelet numbers and smaller heads. 

 

 

    III.              Spikelet Development:  Among the Triticeae, barley (Hordeum vulgare L.) shows a distinct spikelet formation with one to three single-flowered spikelets per rachis node. Based upon the size and fertility of the two lateral spikelets barley can be classified into five row-types (Mansfeld 1950): (1) convar. deficiens, (2) convar. distichon, (3) convar. intermedium, (4) convar. labile, and (5) convar. hexastichon. Three mutant barley loci—vrs2, vrs3, and vrs4—individually determine the conversion from two- (distichon) to six-rowed (hexastichon) barleys but, however, were exclusively found after mutagenesis. The molecular isolation of genes being involved in lateral spikelet fertility may provide an important contribution to further insights into the developmental genetic processes underlying spikelet formation in barley and other grasses.

 

 

    IV.             Pre-Flowering Development in Cereals:  We are interested in the molecular-genetic elucidation of early spike development in small grain cereals. To this end, we are investigating the pre-flowering development of barley and wheat which usually can be divided into three major phases: the leaf initiation (LI) phase, the spikelet initiation (SI) phase, and the spike growth (SG) phase. The duration of each phase can vary depending on environmental conditions (temperature and photoperiod) and contributes independently towards final time to flowering and subsequently yield.