Introduction and primarily evaluation on 16 cooksfoot accessions collected from abroad

Cooksfoot （Dactylis glomerata） is an important forage grass and is widely cultivated in the world due to high forage yield, good quality, and stresses tolerance. The objectives of this study were to collect the necessary data on morphological and phonological traits in order to engage in genetic analysis and breeding program in cooksfoot materials with various chromosome ploidy levels. This study indicated that the growth period of tetraploid accessions was shorter than that of diploid accessions. Among 14 morphological traits, the thousand seed weight, width of inflorescence, length of flag leaf, length of leaf and length of internode showed the relatively high variations among 16 accessions with over 20% of coefficient of variation. The width and length of seed showed a low variation. Exception of PI237601, which would not produce seed in Beijing, other 15 accessions could be classified into 4 groups, indicating all three diploid accessions were in a group, and these diploid accessions were obvious difference with tetraploid accessions.