Germination of Briza maxima L. seeds: effects of temperature, light, salinity and seed harvesting time

Germination behaviour of Briza maxima L. seeds was studied in relation to d ifferent environmental parameters. The influence of harvesting time and aft er-ripening time of the seeds were also considered. Caryopses were collecte d at maturity at the beginning and end of June (harvest1 and harvest2) from wild populations located at the Orbetello Lagoon (Italy) and were germinat ed in deionized water or NaC 1 solutions at 10, 20 and 30 degrees C in the dark or under 12/12 h photoperiod. The results obtained showed that: (i) im mediately after collection, germination rate was higher for harvest 2 seeds , (ii) seed germination was not significatively affected by the light; (iii ) optimum temperature was at 20 degrees C, at which germination started ear lier, (iv) germination percentages at 10 days of culture progressively incr eased during 6 months of after-ripening; (v) the presence of NaCl in the cu lture medium reduced the germination rates (above all of harvest1 seeds) an d seedling growth, but did not induce damage (e.g. necrosis of the root tip ).