Dissecting the yield components in oats

The introduction of the dwarfing gene in wheat not only resulted in a shortening of the straw thus improving harvest index but also improved yield through increased spikelet fertility. In addition it enabled farmers to increase the amount of nitrogen applied to the crop without the risk of lodging. Oats are a relatively tall crop with the height of oats on the current HGCA recommended list being between 110 and 130cm. Lodging can have a major influence on oat crops and may reduce final yields by up to 37%. Dwarf oats could revolutionise oat growing but little is known about potential pleiotropic effects of the dwarfing genes available. Recently, two dwarf winter oats, Hendon and Buffalo, containing the Dw6 gene have been released. The aim of this project is to use a range of genotypes with and without Dw6 to investigate the biochemical, physiological and genetic components of traits associated with yield potential along with segregating individuals of existing mapping populations between parents of contrasting height. Results indicate that dwarf plants tend to be later flowering, have shorter upper internodes, fewer grains per panicle and poor panicle extrusion. The poor extrusion of the dwarf cultivars has been shown to negatively affect yield due to poor filling of spikelets on the basal primarybranches of the oat panicle. However dwarf plants with relatively early flowering, good panicle extrusion and good grain yield were identified in the mapping population indicating that these linkages can be broken