The physiological responses of oak seedlings to warm storage

Abstract

The effects of warm storage (15 °C) on the physiological responses and subsequent field performance of 2-year-old oak (Quercus robur L.) seedlings that had been cold (1–2 °C) stored until May were assessed. Shoot xylem pressure potential, shoot water content, shoot tip dry mass, root electrolyte leakage, and root growth potential were evaluated at regular intervals during the 21-day warm storage period. The date of lifting to cold storage had little effect on the physiological responses to warm storage. Root electrolyte leakage increased after 7 days of storage, despite the fact that root growth potential and survival were unaffected. Values then increased further before decreasing again by the end of the 21-day storage period to values similar to those recorded after 0 or 7 days of storage. Storage for up to 21 days greatly reduced root growth potential and shoot quality after planting in the field. The shoot xylem pressure potential of seedlings declined during the early stage of warm storage, but then increased to values similar to those recorded after cold storage. Shoot water content increased during the early storage period, then declined slightly, but values were higher after 21 days of storage than at the time of placement in warm storage. While most physiological responses fluctuated in a consistent manner, these changes were not necessarily predictable. Root growth potential was a good indicator of plant field performance potential, but the other physiological parameters were less useful to this end.

Influence of seasonal planting date on field performance of six temperate deciduous forest tree species

“…These factors have each been shown to affect seedling vigor and survival (Ritchie et al, 1985;Puttonen, 1987;Lindqvist, 2001;Cabral and O'Reilly, 2005). However, neither factor substantially affected seedling survival in this study.…”

Appraisal of root leakage as a method for estimation of root viability

“…Simulated ambient storage at 158C for 21 days increased REL in pedunculate oak (Quercus robur L.) and Douglas fir seedlings, but the results were not consistent with post-planting performance Cabral & O'Reilly, 2005). When Douglas fir seedlings were placed in warm storage for 21 days REL increased from 47 -63% for seedlings lifted in October and from 38 -58% in December.…”

“…However, REL was considered to be a poor indicator of survival potential survival . In pedunculate oak, REL oscillated during warm storage (Cabral & O'Reilly, 2005). For example, although a 21-day warm storage period reduced plant quality in oak, REL actually declined during the final 7 -10 days of storage was measured over the course of 21 days and REL values went up and down, i.e.…”

Endurcissement au froid et réponse des semis de Juglans nigra transplantés après exposition à différentes modalités de stockage

“…Water relations (Ameglio et al, 2001), bud mitotic activity (Calme et al, 1994), abscisic acid concentration (Li et al, 2003), soluble sugar concentration (Tinus et al, 2000), and chlorophyll fluorescence (Rose and Haase, 2002) are among the many physiological indicators used for conifers. Though these measurements are rapid, they have had limited application in hardwood regeneration programs (Cabral and O'Reilly, 2005;Généré et al, 2004;O'Reilly et al, 2003;Radoglou and Raftoyannis, 2001). …”

“…The electrolyte leakage (EL) method, used extensively as a reliable approach to determine cold hardiness in conifer research (Bigras, 1997;Colombo et al, 1995;Jacobs et al, 2008;Tinus and Burr, 1997), was chosen for this study as it has recently shown success with hardwood seedlings (Cabral and O'Reilly, 2005;Garriou et al, 2000;Généré et al, 2004;Mortazavi et al, 2004;O'Reilly et al, 2003;Radoglou and Raftoyannis, 2001). Cold temperatures reduce enzymatic activity, alter metabolism, and decrease photosynthetic capacity of plant tissues (Dubey, 1997).…”