Changes in mitotic index during onset of dormancy in Douglas-fir seedlings

Abstract

A method is presented for rapid determination of the mitotic index in terminal buds of Douglas-fir, Pseudotsugamenziesii (Mirb.) Franco. Fertilization at planting increased mitotic index but fertilized seedlings entered dormancy at the same time as unfertilized seedlings. Cold storage, prior to dormancy, reduced mitotic index rapidly and was related to reduced height growth the following year. The effects of moderate moisture stress and seed source on mitotic index were slight.

National Fire Plan Research and Development 2004-2005 accomplishment report

“…Iverson (1984) listed morphological targets for some species and stock types from the Pacific Northwest (Table 3.2). Similar targets are provided by Mason and others (1989) for Scots pine and spruce, and for the southern pines by (Mexal and South 1990). Menzies (1988) provides a comprehensive listing of both morphological and physiological specifications for radiata pine.…”

“…This leads to a reduction in reserve carbohydrates and currently available photosynthate, the latter of which is considered to be the primary energy source for root growth in some species (van den Driessche 1987, Phillipson 1988. This was discussed clearly in a recent review of seedling establishment by Reitveld (1989). The take home messages for purposes of this discussion are twofold:.…”

“…Mitotic Index or Ml (number of dividing cells/total number of cells) is used by researchers to investigate bud dormancy (Carlson et al 1980). It has also been used successfully on roots (Dunsworth and Kumi 1982).…”

“…Fluorescence data indicate the technique has the potential to become an extremely valuable tool for determining post-storage seedling quality. For example, seedlings that have high RGP values and optimum field performance in early farmfield tests show near pre-storage levels of FvAR within 24 hours of removal from cold storage and complete recovery within 48 hours (Vidaver et al 1989, Figure 8.4 1989). Both exposure to water deficits, especially at high summer temperatures, and exposure to low temperatures will both induce inactivation.…”

“…sphere ---------decline (Lichtenthaler and Rinderle 1988a), frost hardening and dehardening (Strand andOquist 1988a, Oquist andMalmberg 1989), water stress (Toivonen and Vidaver 1988), nutrient deficiency (Baillon et al 1988), light stress (Oquist and Malmberg 1989), and provenance differences (Vidaver et al 1989(Vidaver et al , 1990 Toivonen and Vidaver (1984) constructed a fluorometer to make FvAR measurements on whole conifer seedlings.…”