A STUDY ON SEED GERMINATION OF AVENA LUDOVICIANA AND THE EFFECTIVE FACTORS IN SEED DORMANCY BREAKING

Wild oat has two seeds in a spikelet that they have different physiological behavior in regard of  seed germiantion. The upper seed of spikelet is smaller and has deeper dormancy than the lower seed. The range of temperature for germination is  ۵˚C  to  ۲۵ ˚C  and optimal temperature is ۱۵˚C. Both kinds of seeds showed the more  germination rate in low temperatures so that ۵ and ۱۰˚C are better for germination than that of ۲۰ and ۲۵˚C.Germination was late and slow in ۵˚C. This study reveled that alternative temperatures (۱۵:۵˚C) was the optimal condition for seed germination. After one and two months,  chilling caused ۶۳.۵% and ۹۷%  germination rate in the lower seeds respectively. Also it caused  ۱۱.۵%  and ۹۲%  germination rate for upper seeds. The results showed that chilling for two months was necessary for seed dormancy breaking.Nitrate ions caused  ۳۲.۷۵%   germination rate in upper seeds and  ۵۷.۲۵%  germination rate  in lower seeds  as compared with those of to controls which were ۱۱.۵%  and  ۱۳.۷۵%  respectively.GA۳ was more effective factor in germination as compared with that of Nitrate ion and cytokinin.Soil stiring caused more germination in burried seeds in different depths of soil.

Keywords:

wild oat , Avena ludoviciana , Seed dormancy , germination