Cameron A D, Sani H
Department of Forestry, University of Aberdeen, Aberdeen AB9 2UD, Scotland, U.K.
Tree Physiol. 1994 Apr;14(4):427-36. doi: 10.1093/treephys/14.4.427.
Patterns of shoot growth and branching were studied over two growing seasons in rooted cuttings collected from both epicormic shoots and seedlings of Betula pendula Roth. Epicormic shoots were induced to sprout on stumps and small logs of 5-, 10- and 30-year-old trees. The use of epicormic shoots enhanced the rooting capacity of stem cuttings collected from these shoots but did not appear to reverse the process of maturation. In this study, maturation was based on characteristics typical of mature trees but not necessarily those of the mother plant, because it was not possible to root cuttings, for comparison, from 5-, 10- and 30-year-old ortets, other than from epicormic shoots. There was evidence of the persistence of mature characteristics through an increase in shoot plagiotropism with increasing ortet age. Rooted cuttings from both seedlings and epicormic shoots, however, assumed an increasingly orthotropic habit with a smaller shoot angle at the end of the first growing season than at the beginning and this continued into the second growing season. Other indications of maturation, such as delayed bud flushing and the incidence of flowering with increasing ortet age, were also evident in rooted cuttings from epicormic shoots. There was a clear difference in branching habit depending on cutting source. Rooted cuttings derived from epicormic shoots produced nearly twice as many lateral branches compared with rooted cuttings collected from seedlings, but this was not an effect of maturation. There was some evidence that rooted cuttings derived from seedlings grew taller than rooted cuttings from epicormic shoots.
在两个生长季节中，对从欧洲白桦的不定芽和幼苗采集的生根插条的枝条生长和分枝模式进行了研究。在5年、10年和30年树龄的树桩和小原木上诱导不定芽萌发。使用不定芽提高了从这些芽采集的茎插条的生根能力，但似乎并没有逆转成熟过程。在本研究中，成熟是基于成熟树木的典型特征，但不一定是母株的特征，因为除了从不定芽外，不可能从5年、10年和30年树龄的采穗母株采集插条进行比较生根。有证据表明，随着采穗母株年龄的增加，枝条的斜向性增加，成熟特征持续存在。然而，来自幼苗和不定芽的生根插条在第一个生长季节结束时比开始时具有越来越直立的习性，枝条角度更小，这种情况持续到第二个生长季节。在不定芽的生根插条中，也明显存在其他成熟迹象，如芽萌发延迟以及随着采穗母株年龄增加开花的发生率。根据插条来源，分枝习性存在明显差异。与从幼苗采集的生根插条相比，来自不定芽的生根插条产生的侧枝数量几乎是其两倍，但这不是成熟的影响。有一些证据表明，来自幼苗的生根插条比来自不定芽的生根插条长得更高。
