Abstract

Studies addressing endodormancy release in adult trees are usually carried out using twigs detached from the trees in the experiments. Potential problems caused by cutting the root–shoot connection when detaching the twigs can be avoided by using grafts as the experimental material. We studied the effects of chilling on the endodormancy release in Norway spruce (Picea abies (L.) Karst.) grafts where twigs of 16-, 32- and 80-year-old trees were used as the scions. The grafts were first exposed to chilling in natural conditions and then samples of them were transferred at intervals to a regrowth test in forcing conditions in a greenhouse. The bud burst percentage, BB%, in the forcing conditions generally increased from zero to near 100% with increasing previous chilling accumulation from mid-October until mid-November, indicating that endodormancy was released in almost all of the grafts by mid-November. The days to bud burst, DBB, decreased in the forcing conditions with successively later transfers until the next spring. Neither BB% nor DBB was dependent on the age of the scion. However, in the early phase of ecodormancy release, the microscopic internal development of the buds was more advanced in the grafts representing the 16-year-old than in those representing the 32- or 80-year-old trees. In conclusion, our findings suggest that no major change in the environmental regulation of endodormancy release in Norway spruce takes place when the trees get older. Taken together with earlier findings with Norway spruce seedlings, our results suggest that regardless of the seedling or tree age, the chilling requirement of endodormancy release is met in late autumn. The implications of our findings for Norway spruce phenology under climatic warming and the limitations of our novel method of using grafts as a proxy of trees of different ages are discussed.

中文翻译：

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挪威释放的异味云杉代表不同年龄的树木

摘要

在成年树木中，有关气味释放的研究通常是在实验中使用从树木上脱落的树枝进行的。通过使用嫁接物作为实验材料，可以避免在拆下树枝时切断根冠连接而引起的潜在问题。我们研究了冷冻对挪威云杉（Picea abies）内味释放的影响（L.）喀斯特地区）移植了16、32和80岁树的树枝作为接穗。首先将嫁接物置于自然条件下冷却，然后将其样品每隔一定时间转移到温室中强迫条件下的再生测试中。从10月中旬到11月中旬，随着先前冷害积累的增加，强迫条件下的芽破裂百分率BB％通常从零增加到接近100％，这表明到11月中旬几乎所有嫁接物都释放了气味。在强迫条件下，芽爆发的天数DBB减少了，随后逐渐转移，直到第二年春天。BB％和DBB都不取决于接穗的年龄。但是，在生态休眠释放的早期，与代表32或80岁树木的植株相比，代表16岁的植株的芽的微观内部发育更为先进。总之，我们的发现表明，当树木变老时，挪威云杉内生气味释放的环境法规没有发生重大变化。结合挪威云杉幼苗的早期发现，我们的结果表明，无论幼苗或树龄如何，都可以在深秋满足对气味释放的寒冷要求。讨论了我们的发现对气候变暖下挪威云杉物候的影响，以及我们使用嫁接作为不同年龄树木的替代物的新方法的局限性。我们的发现表明，当树木变老时，挪威云杉内生香气释放的环境法规没有发生重大变化。结合挪威云杉幼苗的早期发现，我们的结果表明，无论幼苗或树龄如何，都可以在深秋满足对气味释放的寒冷要求。讨论了我们的发现对气候变暖下挪威云杉物候的影响，以及我们使用嫁接作为不同年龄树木的替代物的新方法的局限性。我们的发现表明，当树木变老时，挪威云杉内生香气释放的环境法规没有发生重大变化。结合挪威云杉幼苗的早期发现，我们的结果表明，无论幼苗或树龄如何，都可以在深秋满足对气味释放的寒冷要求。讨论了我们的发现对气候变暖下挪威云杉物候的影响，以及我们使用嫁接作为不同年龄树木的替代物的新方法的局限性。秋末满足了释放异味的寒冷要求。讨论了我们的发现对气候变暖下挪威云杉物候的影响，以及我们使用嫁接作为不同年龄树木的替代物的新方法的局限性。秋末满足了释放异味的寒冷要求。讨论了我们的发现对气候变暖下挪威云杉物候的影响，以及我们使用嫁接作为不同年龄树木的替代物的新方法的局限性。