Genetic variation in the relative dominance of mixed swards: Potential influence and its mechanism

• Published in: Nippon Sōchi Gakkaishi Vol. 44; no. 4
• Main Author: Sugiyama, S. (Hirosaki Univ., Aomori (Japan))
• Format: Journal Article
• Language: English
• Published: 01.01.1999
• Subjects: DACTYLIS GLOMERATA; DOMINANT SPECIES; ESPECE DOMINANTE; ESPECIES DOMINANTES; GENETIC VARIATION; MIXED PASTURES; PASTIZAL MIXTO; PRAIRIE MIXTE; VARIACION GENETICA; VARIATION GENETIQUE
• ISSN: 0447-5933
• DOI: 10.14941/grass.44.303

This study examined the effects of intraspecific genetic variation on botanical structure of mixed swards by comparing the performances in two-species mixtures among different cultivars (cultivated populations) in three grass species: Lolium perenne L., Dactylis glomerata L. and Festuca arundinacea Schreb. There were significant differences in botanical composition of the grass-grass mixtures among the cultivars. The relative contribution to the total biomass (relative dominance) of the mixtures ranged from 54 to 90% between L. perenne cultivars, from 45 to 85% between D. glomerata cultivars and 11 to 43% between F. arundinacea cultivars. The relative dominance in the mixtures showed a close relationship with tiller size of the monoculture swards in the three species. However, the relationship differed among the three species: a positive linear relationship in L. perenne, a positive quadratic relationship in D. glomerata and a negative quadratic relationship in F. arundinacea. The following hypothesis was proposed to explain the results: the differences in relative dominance or mixtures among the cultivars are determined by the relative balance between potential growth and regrowth ability after defoliation, both of which are closely associated with tiller size, and that the three species differed in the relative importance between them