DIFFERENTIAL ADAPTABILITY OF ONE POPULATION OF DACTYLIS GLOMERATA SUBSP. MARINA AND THE HYBRID BETWEEN "MARINA x GLOMERATA"

Resumen

One natural population of cocksfoot {Dactylis glomerata) of subsp. marina (Mm504) and the natural hybrid between subsp. marina and subsp. glomerata (Mm794), were clonally replicated as spaced plants in two environments in the same locality, to detect differential genetic responses to the soil environment. Environment 1 had a less acid soil with more nutrients, less sand and less drought than environment 2. Morphological and agronomic traits were recorded, and most of them showed significant differences between populations, between environments and between plants (within populations). Mm794 had more erect plants and higher reproductive output than Mm504, but less biomass production in general. Environment 2 was stressful for several characters (e.g. there was no winter growth and some plants of Mm504 did not flower in both years, 1998 and 1999), but there was significant genotype x environment interaction in many traits. Leaf biomass at the reproductive stage (which presented crossover interaction) and growth habit were the traits with highest phenotypic plasticity, but each population showed plasticity for different traits. The effect of the environment on the differences between populations depended on the trait considered. Seed production was positively correlated with flag leaf length (r=0.63***).