ABSTRACT
Annual ryegrass is a major annual cool season crop in the southeastern USA, available from mid autumn to late spring. It has high palatability, forage quality, seedling vigor and dry matter (DM) yield. Due to low availability of cool season annuals and perennials in early autumn and winter, animals are fed on stored forages. Annual ryegrass, along with perennial grasses, has high spring production but is lacking in late autumn and winter production. The primary objective of the breeding project was to shift the yield distribution of annual ryegrass towards the winter to make it available for grazing and to reduce the dependence of livestock on stored forages and grain. The base population was created from six top performing cultivars in Alabama. Plants were open-pollinated and bulk harvested for two seasons to create a random mating base population (C0). Three cycles of phenotypic recurrent selection along with C0 were used to study correlated responses such as heading date, plant type and seed yield. Each population was increased in replicated seed increase nurseries using a randomized complete block (RCB) design with four (2007/08) or two (2008/09) individual isolation nurseries per population. Each plot consisted of 200 plants and heading and plant type data were collected on each plant during the reproductive stage. For all correlated responses, C1 showed a significant change from C0 with exception of seed yield in 2008. There was no further change during successive cycles (C2, C3). With three cycles of selection, selected populations shifted their heading date 8 d earlier, had a more erect growth habit and increased seed yield than C0. Of the three correlated responses, seed yield has shown a population x evaluation year interaction.
