Seed heteromorphy influences seed longevity in Aegilops.

The genus belongs to the secondary gene pool of wheat and has great importance for wheat cultivar improvement. As a genus with only annual species, regeneration from seeds in is crucial. In several species in , spikes produce different seed morphs, both in size and germination patterns. However, little is known about the ecology of seed germination, nor about the seed longevity in this genus. Here we investigated the germination phenology of under laboratory and field conditions and assessed longevity of different seed morphs of five additional species using controlled ageing tests. Large seeds were short-lived and germinated faster than small seeds in most of the species. Field experiments with showed that large seeds of the dimorphic pair germinated 3 months after dispersal in contrast to 14 months for smaller seeds. Differences in longevity were detected not only in dimorphic seed pairs, but also among seeds from different positions on the spike. Our results indicate that different longevities in seed morphs of may reflect a different soil seed bank persistence, with smaller seeds able to maintain a higher viability after dispersal than larger ones, thereby spreading seedling emergence over two years. Differences of seed germination and longevities between seed morphs in may have important implications for seed conservation and reinforce the hypothesis of a bet-hedging strategy in the germination ecology of this genus.

Creator (organisation)

Guzzon, Filippo

Orsenigo, Simone

Gianella, Maraeva

Müller, Jonas V.

Vagge, Ilda

Rossi, Graziano

Mondoni, Andrea