Maternal Environment Effects on Plant Growth and Germination of Two Strains of Thlaspi arvense L.

The influence of maternal environment on plant development and seed germination of early- and late-flowering strains of Thlaspi arvense L. was studied. Compared to plants grown at 30⚬/10⚬C, those grown at 15⚬/10⚬C and 20⚬/10⚬C flowered more slowly, were shorter, and grew fewer leaves; seed production, however, was greatest at 20⚬/10⚬C. Plants of the late-flowering strain produced more leaves than those of the early-flowering strain, but there were no differences between strains in vegetative dry weight or height at harvest. On average, fresh seeds from plants of the late-flowering strain germinated at a faster rate than those from plants of the early-flowering strain. Seed dormancy increased with increasing temperature in which they developed, thus explaining some of the differences reported in the literature regarding germination of fresh seeds of T. arvense. The evolutionary implications of these results are discussed in relation to the single gene differences between the two strains.