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Rapid and Effective Germination Methods for Overcoming Seed Dormancy in Annual Canarygrass
Author(s) -
Matus-Cádiz M. A.,
Hucl P.
Publication year - 2005
Publication title -
crop science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.76
H-Index - 147
eISSN - 1435-0653
pISSN - 0011-183X
DOI - 10.2135/cropsci2004.0347
Subject(s) - germination , dormancy , biology , seed dormancy , agronomy , horticulture , potassium nitrate , gibberellic acid , panicle , potassium , chemistry , organic chemistry
Dormancy in pedigreed Phalaris seed can lead to unsatisfactory germination in seed testing. The objective was to determine the effectiveness of recommended germination methods in overcoming seed dormancy in annual canarygrass ( P. canariensis L.). In 2003, ‘CDC Maria’ was grown at two locations in Saskatchewan, Canada. At maturity, panicles were harvested and stored at –20°C. Four replications of 50 seeds were used in each experiment. Hulled and hand dehulled seed were (i) stored at 23°C for 0 to 16 wk before germinating at 23°C, (ii) germinated at 15 to 30°C (with and without light), (iii) allowed to imbibe water at 23°C for up to 96 h, (iv) treated with pricking, hydrogen peroxide (H 2 O 2 ), gibberellic acid (GA), ethephon (2‐chloroethylphosphonic acid), potassium nitrate (KNO 3 ), chilling, and heating before germinating at 23°C, and (v) treated with KNO 3 , heating, and chilling before germinating (with and without light) at 15°C, 15/25°C (16/8h), and 20/30°C (16/8h). Mean germination was tested to be significantly different ( P = 0.05) from 95% germination by t tests. The after‐ripening period required to overcome primary dormancy in hulled seed was 8 to 10 wk longer than in dehulled seed. Hulled seed developed deeper secondary dormancy compared with dehulled seed, particularly at 20 and 25°C, with neither displaying <95% germination at 15°C or >10% at 30°C. Dehulled seed imbibed sufficient water to initiate germination 2 d faster than hulled seed. Applications of H 2 O 2 and GA overcame dormancy in dehulled seed, while none of the treatments overcame hulled seed dormancy. Dehulled and hulled seed displayed unsatisfactory germination, regardless of treatment or light regime, when germinated under an alternating temperature regime of 20/30°C. We recommend (i) hand dehulling seed, (ii) treating hulled seed with 0.01 M KNO 3 , or (iii) treating hulled seed with heat (3 d at 30°C) before germinating at 15°C for 10 d in darkness on top of blotters to overcome seed dormancy rapidly and effectively in annual canarygrass.