外来种无瓣海桑化感作用研究初报

Primary studies on allelopathy of Sonneratia apetala

种子萌发率和胚根长度作为测量指标,以化感效应敏感指数 RI 为评价指标,研究了无瓣海桑(Sonneratia apetala)各器官的水浸液对海桑(Sonneratia caseolaris)和无瓣海桑种子发芽的影响。结果表明:1)无瓣海桑的各器官水浸液对海桑种子萌发均起抑制作用,高浓度下抑制效应明显;2)不同浓度无瓣海桑根的水浸液对海桑的胚根长均起抑制作用,高浓度下显著抑制,随着浓度降低抑制作用减弱;无瓣海桑的枝、叶和果的水浸液对海桑的胚根长表现为"高抑低促",即高浓度下显著抑制,随着浓度降低抑制作用减弱甚至转为促进;3)无瓣海桑各器官的水浸液对本身种子的发芽表现为"高抑低促";4)无瓣海桑果的水浸液对本身的胚根长表现为高浓度下显著抑制,随着浓度降低抑制作用逐渐减弱;无瓣海桑枝、叶和根的水浸液对本身的胚根长表现为"高抑低促";5)无瓣海桑各器官的水浸液中果的水浸液对海桑或无瓣海桑种子发芽和胚根长的抑制作用最强。

In this paper,the allelopathy of aqueous extracts from different organs of Sonneratia apetala on the seed germination of S. caseolaris and S.apetala were studied.The following results were obtained:1)Aqueous extracts from different organs of S.apetala inhibited the germination of S.caseolaris.At high concentration,the germination of S.caseolaris was significantly inhibited;2) Aqueous extract from S.apetala roots inhibited the radicle length of S.caseolaris.At high concentration the radicle length was inhibited significantly,while with decreasing concentration,the inhibitory effects got weaker.Applied with the extracts of S.apetala branch,leaf and fruit,the radicle length of S.caseolaris was significantly inhibited at high concentration;while with decreasing concentration the inhibitory effects got weaker and even turned into stimulating effects.3)Applied with the extracts from different organs ofS.apetala,the germination orS.apetala was stimulated at low concentration and inhibited at high concentration.4)At high concentration of aqueous extract from S.apetala fruit,the radicle length of itself was inhibited significantly,while with decreasing concentration the inhibitory effects got weaker.Applied with the aqueous extracts of S.apetala branch,leaf and fruit,the radicle length of S.caseolaris was stimulated at low concentration and inhibited at high concentration;5)As to the inhibitory effects on the germination and radicle length of S.apetala and S.caseolaris,the effects of aqueous extract from Sonneratia apetala fruit were stronger compared with that of other organs.