关键词: 油松, 种源, 生态型, 种子发芽生态学, 种子休眠

Abstract: 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 improvement. 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.

Key words: Pinus tabulaeformis Carr., Provenance, Ecotype, Seed germintation ecology, Seed dormancy