山桃稠李种子休眠机理及催芽技术

Dormancy Mechanism and Germination Conditions of Prunus maackii Seeds

采用试验的方法研究了山桃稠李种皮的透水性、胚形态后熟及催芽过程中发芽抑制物质的转化过程,探讨了山桃稠李种子休眠机制。结果表明:山桃稠李种皮透水性差,刺破种皮和完整种皮的山桃稠李种子分别吸水32.97%、27.79%,处理之间差异显著(P<0.05);山桃稠李种子存在明显的胚后熟现象,种子成熟时种胚尚未发育完全,层积处理后胚率达到35.08%,与层积前相比差异显著(P<0.05);山桃稠李种子内部存在发芽抑制物质,随着层积时间的延长,发芽抑制物质活性下降,经变温层积山桃稠李种子浸提液处理的白菜籽,其发芽率分别从18.7%提高到56.0%;种子浸提液对白菜籽发芽后苗高和根长生长的影响,随层积时间的延长,抑制作用减小。山桃稠李种子催芽最佳处理组合为500 mg·L-1 GA3溶液浸种48h,先暖温层积90d,再低温层积130d,苗圃场圃发芽率达到43.8%。研究结果显示:山桃稠李种子为综合休眠类型,采用赤霉素处理结合层积催芽,可以有效解除种子休眠。

An experiment was conducted to study the seed coat permeability,embryo morphological post-maturation and germination inhibitory substance in Prunus maackii seeds.The dormancy mechanism of P.maackii seeds was discussed.Results show that the water permeability of seed coat of P.maackii is low.Water absorption rates were 32.97% and 27.79% for scarified seeds and non-scarified seeds respectively（P0.05）.An obvious phenomenon of embryo morphological post-maturation of P.maackii was observed.The proportion of the length of embryo to the length of endosperm was 35.08% for the seeds after stratification treatment,which was significantly different from that of the control（P0.05）.Germination inhibitory substance was found in P.maackii seeds.The activity of germination inhibitory substance declined with the prolonged stratification time.Cabbages were treated with the extraction liquid from P.maackii seeds after the combination of warm and cold stratification.Seed germination percentage of the cabbages increased from 18.7% to 56.0%.The inhibition effect of the extraction liquid from P.maackii seeds on the growth of seedling height and root length decreased with the prolonged stratification time.The optimal combination for the seed germination of P.maackii was to soak the seeds with 500 mg·L-1 GA3 for 48h by a 90-day warm stratification followed by 130-day cold stratification,and the seeds showed an average germination rate of 43.8%.P.maackii seeds belong to combinational dormancy.Treating the seeds with GA3 combined with stratification could effectively break the seed dormancy in P.maackii.