VARIATION IN DEVELOPMENTAL PATTERNS OF WILD BARLEY (HORDEUM-SPONTANEUM L) AND CULTIVATED BARLEY (HORDEUM-VULGARE L)

Six wild barley (Hordeum spontaneum) accessions, from a diverse range of habitats, and two spring-cultivated barleys, were examined for vari ation in durations of development phases. The durations of the leaf in itiation and spikelet initiation phases were longer and spikelet growt h phases shorter, in wild than in cultivated barley. Across all wild a nd cultivated barleys the rate and duration of spikelet initiation wer e negatively correlated, but neither was related to the number of spik elets per spike. The number of spikelets was positively correlated wit h the number of leaves and the ratio of the number of spikelets to the number of leaves declined with increasing time to anthesis, indicatin g that each successive leaf was associated with a diminishing increase in the number of spikelets. The duration of culm elongation and final culm length were shorter in accessions of cultivated barley compared with wild barley. This paper also discusses the feasibility for increa sing the number of spikelets per spike through breeding for genetic ch anges in lengths of pre-anthesis phases of development.