摘要
我们在实验室条件下研究了油松不同种源及生态型的种子发芽与温度、光照、水分逆境和层积处理的关系。温度采用了5个水平:20℃,25℃,30℃,35℃(以上为恒温)和30℃/20℃(变温)。光照分为2个水平(有光和无光)。以PEG-6000的不同浓度组成水势逆境梯度:0,-2,-4,-6(bar)。层积处理的条件是以蛭石为介质,湿度为60％,温度为3℃,层积时间37天。研究结果说明,油松种子发芽要求的最适生态条件;20—25℃,有光,水分充足。30℃特别是35℃以上的高温,无光,水势低于-2(bar)均对发芽不利。不同种源和不同生态型种子发芽的差异表现在对上述逆境条件的敏感性和休眠要求的有无上。不同生态型种子发芽对高温和水分逆境的敏感性的顺序是(从最不敏感的开始):东北型、东部型、中部型、西南型、西北型、南部型。对无光敏感性的顺序(从最不敏感的开始):东部型、西南型、中部型、东北型、西北型、南部型。经层积处理后,南部型的种子发芽率显著提高,东部型略有提高,中部型、西南型无变化,而西北型和东北型则大为降低。可见,南部型的种子有明显的休眠要求,这是原产地冬季比较温暖湿润的种群,为了避免过早萌发,所进行的自然选择。
Laboratory seed germination of Pinus tabulaeformis of different provenances and ecotypes were studied according to their responses to various temperatures (20℃, 25℃, 30℃, 35℃ and 20/30℃ of night/day), light conditions (with and without daily illumination of 8 hours), moisture stress (0, -2, -4, -6 bar) and stratification treatment (chilling at 3℃ for 37 days with moistened vermiculite). The moisture stresses were made using PEG-6000 solutions. Results showed that 20—25℃ and daily illumination with sufficient water supply to be the optimum ecological condition for seeds of this pine as a species to germinate while 30℃, especially higher than 35℃, non-illumination and moisture stress (below-2 bar) being unfavorable. Seeds of different provenances and ecotypes had their own germination charactoristics in that they responded differently to these unfavorable conditions and had distinctive dormancy requirement. The south (S) ecotype was most sensitive to high temperature and moisture stress, followed by ecotypes of north-west(NW), south-west(SW), central(C), east(E) and northeast(NE). The sensitivity sequence illumination (from the most sensitive to the least) was: S, NW, NE, C, SW and E. Stratified seeds of S reached a significanly higher germination percentage compared with control. Seeds of E germinated a little better after stratification while C and SW showed no improvment. On the contrary, the germination percentage of NW and NE were considerably reduced by the pretreatment. It could be concluded that the south ecotype seeds developed dormancy requirement in preventing early germination under rather warm and wet weather.
出处
《林业科学》
EI
CAS
CSCD
北大核心
1989年第6期493-501,共9页
Scientia Silvae Sinicae
关键词
油松
种子
发芽
生态学
种源
Pinus tabulaeformis Carr.
Provenance
Ecotype
Seed germintation ecology
Seed dormancy
