Kainer K A, Duryea M L, White T L, Johnson J D
Department of Forestry, University of Florida, Gainesville, FL 32611, USA.
Tree Physiol. 1991 Dec;9(4):479-89. doi: 10.1093/treephys/9.4.479.
Bud dormancy of root wrenched and unwrenched slash pine (Pinus elliottii Engelm.) seedlings growing in a forest nursery was measured on five lifting dates. Determination of bud dormancy was based on days to budbreak (DBB) under optimal growing conditions, mitotic activity in the apical meristem, chilling hours accumulated, and bud morphology. Based on DBB, seedlings were most dormant at Lift 2 on November 24 after exposure to 189 hours below 10 degrees C and 93 hours below 6.7 degrees C. Mitotic activity in the apical meristem was at its lowest 23 days later at Lift 3, possibly indicating the period when seedlings are most resistant to transplanting stresses. Multiple wrenching resulted in a slight shift in the dormancy cycle as wrenched seedlings set bud sooner in the nursery and broke bud sooner at the planting site in the spring than control seedlings. This implies that wrenched seedlings can be successfully lifted from the nursery earlier and will initiate spring shoot growth earlier than control seedlings.
在五个起苗日期测量了森林苗圃中根系受扭伤和未受扭伤的湿地松（Pinus elliottii Engelm.）幼苗的芽休眠情况。芽休眠的测定基于最佳生长条件下的芽萌发天数（DBB）、顶端分生组织的有丝分裂活性、积累的低温小时数以及芽的形态。根据DBB，在11月24日的第2次起苗时，幼苗在经历了189小时低于10摄氏度和93小时低于6.7摄氏度的低温后处于最休眠状态。顶端分生组织的有丝分裂活性在23天后的第3次起苗时降至最低，这可能表明幼苗对移植胁迫最具抗性的时期。多次扭伤导致休眠周期略有变化，因为受扭伤的幼苗在苗圃中比对照幼苗更早形成芽，并且在春季种植地点更早打破芽休眠。这意味着受扭伤的幼苗可以比对照幼苗更早地从苗圃成功起苗，并更早地开始春季新梢生长。
