4种禾草种子发芽条件的筛选研究

Seed Germination Conditions of Four Grass Forages Species

针对马唐(Digitaria sanguinalis(L.)Scop)、止血马唐(Digitaria ischaemum(Schreib.)Schreib.)、细弱隐子草(Cleistogenes gracilis Keng)和糙隐子草(Cleistogenes squarrosa(Trin.)Keng)4种禾本科牧草种子发芽率低的现象,使用不同温度、不同浓度KNO3溶液和预冷等处理对其进行打破休眠和促进萌发的研究,并对供试种子的适宜发芽条件进行筛选。结果表明:马唐种子不存在休眠问题,预冷和KNO3溶液对促进其萌发均没有显著效果;止血马唐种子存在休眠且生活力偏低,预冷能够打破休眠,KNO3处理能够有效提高其种子的生活力(P<0.05);细弱隐子草和糙隐子草发芽率低主要原因是种子生活力低,KNO3处理能够极显著提高种子的生活力和发芽率(P<0.01)。4种种子的最适发芽条件分别是:马唐种子用KNO3(0.2%)处理或不处理,在30℃恒温发芽;止血马唐、细弱隐子草和糙隐子草种子均为用KNO3(0.2%)处理并预冷(7d)后20～30℃变温发芽。

Different methods （temperatures, KNOa solutions and pre-cooling treatments）were investigated to break the dormancy and promote seed germination of： Digitaria sanguinalis （L.）Scop, Digitaria ischaemum （Schreib.） Schreib, Cleistogenes gracilis Keng and Cleistogenes squarrosa （Trin.） Keng. Results indicated that Digitaria sanguinalis seeds had no dormancy and both pre-cooling and KNO3 solution did not significantly promote germination. Digitaria ischaemurn seeds had both dormancy and low-viability; pre-eooling treatment could break the dormancy effectively and KNO3 solution could effectively improve viability. The low seed germination percentage of Cleistogenes gracilis and Cleistogenes squarrosa was enhanced with a KNO3 solution improving both seed viability and seed germination percentage. Optimum seed germination conditions were. Digitaria sanguinalis seed germinated at 30℃ with or without KNOa （0.2%） solution treatment ; Digilaria lschaemum, Cleistogenes gracilis and Cleistogenes spuarrosa seeds germinated at 20- 30 ℃ with KNO3 （0.2 %） solution and pre-cooling treatment （7 d）.