Genome size variation of Lotus peregrinus at evolution canyon I microsite, lower nahal oren, Mt. Carmel, Israel

On the basis of previous studies showing a positive correlation between number of copies of retrotransposons and geographical environment, we hypothesized that different ecogeographical conditions on opposite slopes of Evolution Canyon I could cause intraspecific variation in plant genome size. To test this hypothesis, we chose Lotus peregrinus L. (annual, self-pollinator) as the first candidate because of its biological contrast to the previously studied carob tree (long-lived, cross-pollinator). Absolute nuclear DNA content of 60 genotypes of L. peregrinus was estimated by PI flow cytometry, with tomato (Lycopersicon esculentum cv. Stupicke) as internal reference standard. The mean 2C-value in L. peregrinus was 2.546 pg, ranging from 2.39 pg to 2.71 pg. The mean 2C-value was higher in plants from the south-facing slope (2.549 pg) than from the north-facing slope (2.544 pg), but we were not able to show significant interslope differences in genome size.