Abstract
A collection of ten local populations of white clover (Trifolium repens L.), primarily from the old native grasslands of the northern Tohoku region, were transplanted as spaced plants along with three commercial cultivars Kent Wild, Huia and North White. Characteristic growth patterns and associations between plant characteristics and geographical factors were investigated for populations from the northern Tohoku region and compared with the commercial cultivars. Leaflet length, petiole length, internode length and stem thickness of the nine local populations with exception of KAMISODE-1 were smaller than those of the middle-leaved cultivar Huia. Principal component analysis was used to integrate these four morphological characteristics over two years of measurements, and the second principal component of the local populations demonstrated that the relative length of internode to the other three characteristics was shorter than for the three cultivars. In the nine small-leaved local populations, linear and quadratic relationships were investigated between all characteristics and three geographical factors (latitude, elevation and mean winter temperature). Winter survival showed significant fits with quadratic regression models against all three factors (p<0.05, p<0.01 and p<0.05, respectively). Moreover, winter survival is positively correlated to plant spreading (R^2=0.6329, p<0.05). SODEYAMA population collected from Iwate prefecture has the best winter survival and the largest plant spreading in the all small-leaved local populations.
