THIRTY YEARS' STUDIES ON BREEDING GROUND-COVER CHRYSANTHEMUM NEW CULTIVARS

Beginnig in autumn of 1961, Chen and his colleague crossed 3 hardy, wild endranthema species (D. indicum var. acutum, D. chanetii and D. lavendulifolium). with some early chrysanthemum cultivars (D. x grandiflora). During 1962–1963, we selected twice by giving points of evaluation by experts, resulting in 13 cys. of the Rock Daisy ("Hong Yan", etc.) selected and named. Butextention and research work was dropped during the "Cultural Revolutions" for more than 10 years after 1965.

In 1981, we continued the research work of chrysanthemum breeding by giving lectures and making practises. But studies on breeding Dibeiju or Ground-Cover Chrysanthemums were really carried on after 1984 by the authors (Chen et al.). For instance, D. vestitum, one of the most important pqrents in distant crossing, was discovered in large areas and introduced by the first author from Tian Ju Shan of Anhui Province (1984); "Mei Ai Fen" was selected out from early chrysanthemum mixed seedlings by him (1984); the aim of breeding adjusted (Chen et al., 1985); the research project supported by Beijing Committee of Science and Technology (1987); and the cultivar group name Dibeiju (Ground-Cover Chrysanthemum) appointed and used. (Chen et al., 1987)

During recent 6 years (1987–1993), 5 batches of Dibeiju new cvs. have been bred and distributed for extension. Over 5 000 000 plants of it have been in cultivation in whole China until the end of June, 1993.