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Research article2003Peer reviewed

Variation in chilling requirements for completing bud rest between provenances of Norway spruce

Hannerz M, Ekberg I, Norell L

Abstract

Winter dormancy in forest trees starts with a rest stage, during which buds remain inactive even if they are exposed to growth-promoting conditions, and is followed by quiescence. The transition from rest to quiescence requires chilling. The amount of chilling needed to complete the rest phase was tested in different provenances of Norway spruce (Picea abies (L.) Karst.). One-year-old seedlings from eight provenances were grown in a climate-chamber experiment, and from ten provenances (with one Sitka spruce provenance, for comparison) in a nursery experiment. The rest status of these seedlings after exposure to chilling for various durations was tested by measuring the time they took to break bud after transfer to growth-promoting conditions. In the nursery experiment, the chilling requirement was high in provenances from Denmark, Germany and Belorussia, and low in provenances from northern Sweden and Russia. Provenances from southern Sweden and Norway had intermediate chilling requirements. The Sitka spruce provenance had a very high chilling requirement. A high chilling requirement suggests better adaptation to maritime conditions and warm winters. However, absolute differences between provenances were small. The chilling requirement was mostly fulfilled in November-December. In the climate chamber experiment the chilling requirement could not be determined, because the rest phase had started to break before the chilling treatment was applied. The northern Swedish provenance consistently showed the lowest temperature sum requirement for budburst while the southern German provenance showed the highest temperature sum requirement in most treatments

Keywords

PICEA-ABIES; FLUSHING TEMPERATURE; PINUS-SYLVESTRIS; BURST PHENOLOGY; DOUGLAS-FIR; DORMANCY; BUDBURST; TREES

Published in

Silvae Genetica
2003, Volume: 52, number: 3-4, pages: 161-168 Publisher: J D SAUERLANDERS VERLAG

    UKÄ Subject classification

    Agricultural Science
    Forest Science

    Permanent link to this page (URI)

    https://res.slu.se/id/publ/5366