Characterization of cocksfoot (Dactylis glomerata L.) population for growth traits and summer dormancy

Cocksfoot is one of the four most important forages in the world,it is persistent and summer drought tolerant. under mediterranean climate,one way to produce without irrigation is to use plants resistant to drought,such as some perennial grasses as cocksfoot. the present work was conducted during 2011/2012 cropping season to evaluate some traits of progeny generated from a cross between a summer dormant genotype kasbah cv and a summer active genotype from medly cv under mediterranean climate.the aim of this study was to gather hybrids pools according to common features with relation to summer dormancy. measurements of dry matter yield,heading date,plant height,plant growth rate,senescence and summer dormancy were taken for the 229 f1 hybrids. results showed a large variability between hybrids for all traits. 4% of hybrids were more dormant than the parent kasbah,35 % of hybrids yielded more than medly,73.8 % of progeny exceeded parents growth rate,60 % had the greatest biovolume,more important than both parents. significant correlations (p <0.0001) were found between all traits except heading date and senescence. cluster analysis (ca) revealed eight groups and subgroups which showed 80 % of phenotypical similarities within hybrids and parents.