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Analysis of differences in field performance of vegetatively and seed-propagated <i>Eucalyptus</i> varieties I: survival and leaf gas exchange


MEO Mokotedi
MP Watt
NW Pammenter

Abstract

The aim of this study was to compare survival rates and leaf gas exchange of micro- and macro-propagated Eucalyptus grandis × E. nitens, and seed-propagated E. grandis and E. nitens, at a site in Hilton, KwaZulu-Natal, South Africa, where the conditions were suitable for cold-tolerant hybrid eucalypts. Fourteen months after planting, 50% of micropropagated E. grandis × E. nitens had survived, compared with 87% for macropropagated E. grandis × E. nitens, 53% for seed-propagated E. grandis and 93% for E. nitens. Differences in instantaneous leaf gas exchange and parameters derived from the light and CO2 responses of gas exchange were not significant between micro- and macro-propagated plants, but were significant between species. All trees used water more efficiently during photosynthesis at 16 months (winter; June 2004) than at 14 months (autumn; April 2004) after planting. However, micropropagation yielded plants that were most vulnerable to the combination of prolonged dry conditions and air frost.

Keywords: drought stress; Eucalyptus grandis × E. nitens; macropropagation; micropropagation

Southern Forests 2009, 71(4): 267–271

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eISSN: 2070-2639
print ISSN: 2070-2620