Intra-Population Variation in Nuclear DNA Amount, Cell Size and Growth Rate in Poa annua L.

Abstract

An 80% variation in nuclear DNA amount at constant chromosome number has been found between families of seed progeny derived from established plants of Poa ann ua L. taken from a single pasture population in North Wales. The 2C DNA amount varied from 2 9pg to 5 2pg. This variation was positively associated with variation in cell size, negatively correlated with variation in seedling growth rate, but was not associated with variation in life-history. We suggest that this variation may enable individuals to exploit different temporal, micro-climatic niches within the grassland habitat. Key-words: Intra-population variation, nuclear DNA amount, cell size, growth rate, temporal niche, grassland