Effect of scarification, temperature and light on seed dormancy of weeds from the northwest of Argentina

SAMPIETRO, D.A.

Tucumán (Argentina)

Congreso; XXI Annual Meeting of Tucuman Biology Society; 2005

Tucuman Biology Society (publicado en Bio Cell 29 (1), 66, 2005)

Seed dormancy of weeds is regulated by some factors such as seed coats, light and temperature.  The aim of this work was to establish the response of seeds from three weeds to mechanical scarification, light and different temperature regimes. Germination assays were conducted in Petri dishes. In each Petri dish 25 seeds of Amaranthus quitensis L., Sida rhombifolia L. or Brassica campestris L. were placed on Whatman Nº1 paper and 3 ml of distilled water were added. Groups of five Petri dishes of each species were subjected to different temperature regimes (10ºC, 35ºC, 20-25ºC, 10-35ºC) in the dark. Another group was placed in a photoperiod of 12hs/12hs (dark/light, 20-25ºC). A known seed weight of each species was scarified with sand paper and exposed to the photoperiod indicated above. Seed germination was daily determined. Seed scarification increased the germination of S. rhombifolia and B. campestris seeds. Germination of A. quitensis was not affected. Light had no effect. The temperature regime of 10-35ºC produced higher germination than constant and germination at 35ºC was higher than that at 10ºC on the three assayed species. Seed coats had an important role on seed dormancy of S. rhombifolia and B. campestris, but not on A. quitensis. S. rhombifolia and B. campestris were more sensitive to different temperature regimes than A. quitensis