caa a22 4500 463218345 CHVBK 20180405153204.0 cr unu---uuuuu 170326e20070101xx s 000 0 eng 10.1007/s11056-006-9016-5 doi (NATIONALLICENCE)springer-10.1007/s11056-006-9016-5 Tan Weixing Department of Science, Grande Prairie Regional College, 10726 - 106 Avenue, T8V 4C4, Grande Prairie, Alberta, Canada aut Impacts of nursery cultural treatments on stress tolerance in 1+0 container white spruce ( Picea glauca [Moench] Voss) seedlings for summer-planting [Elektronische Daten] [Weixing Tan] Impacts of nursery cultural treatments (T) on stress tolerance of greenhouse-grown 1+0 container white spruce (Picea glauca [Moench] Voss) seedlings (mean height 24cm, root collar diameter 3.1mm) for summer planting were studied. Seedlings were subjected to 12-h short-day treatments of 0 (T0), 3 (T3), 7 (T7), 10 (T10), or 15 (T15)days, followed by 0, 7, 17, 40, or 46days of reduced N supply, respectively. Relevant physiological and morphological factors were examined concurrently. Foliar N concentrations exceeded optimal levels and differed little among treatments, suggesting a minor confounding role for N reduction. Both frost and drought tolerance increased incrementally from T0 through T15. Electrolyte leakage index decreased steadily from T0 (25% for roots, 17% for needles) to T15 (1% for roots, 2% for needles) after 2-h exposure of fine roots to −2°C and of needles to −8°C. Withholding soil watering for 19days caused 80% mortality among seedlings in T0, 50% in T3, and <10% in T7-T15. The transpiration decline curve suggested that enhanced drought tolerance was largely attributable to quicker stomatal closure during water stress and lower cuticular transpiration rate. The treatments increased root growth capacity on a per-seedling, but not per-root-mass, basis. Needle primordia were developed in all T7-T15 seedlings but not in T0 and T3 treatments, suggesting that nurseries may need no more than 7days of blackout application for conditioning spruce seedlings for summer planting. Shoot dry weight fraction increased gradually from T0 through T15 and was linearly correlated with needle specific weight and frost tolerance, and may thus be useful in monitoring progress of conditioning treatments. Springer Science+Business Media B.V., 2006 Short-day nationallicence Conditioning nationallicence Drought tolerance nationallicence Frost tolerance nationallicence Physiology nationallicence New Forests Kluwer Academic Publishers 33/1(2007-01-01), 93-107 0169-4286 33:1<93 2007 33 11056 https://doi.org/10.1007/s11056-006-9016-5 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s11056-006-9016-5 text/html Onlinezugriff via DOI NATIONALLICENCE 100 1- Tan Weixing Department of Science, Grande Prairie Regional College, 10726 - 106 Avenue, T8V 4C4, Grande Prairie, Alberta, Canada aut NATIONALLICENCE 773 0- New Forests Kluwer Academic Publishers 33/1(2007-01-01), 93-107 0169-4286 33:1<93 2007 33 11056 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer