Needle flavonoid variation in coastal Douglas-fir (Pseudotsuga menziesii var. menziesii) populations

Abstract

The variability of six Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco var. menziesii) populations was studied with the help of needle flavonoids. Of the two proanthocyanidins and six flavonols detected and measured by high performance liquid chromatography, myricetin and prodelphinidin allowed partial separation of the sampled coastal Douglas-fir populations into three geographical groups. Even though conspicuous differences were found between the northernmost and southernmost provenances, flavonoid markers were insufficient to identify the origin of a coastal Douglas-fir population without ambiguity. In accordance with other genetic markers, it would be inappropriate to recognize races within the sampled area of coastal Douglas-fir. From a biogenetical point of view, the synthesis of prodelphinidin appears to be governed by a gene present in two codominant allelic forms. The alleles are differently expressed from one population to another in such a way that there is a latitudinal cline of prodelphinidin throughout the sampled coastal Douglas-fir populations. The gradual decrease of prodelphinidin from south to north tends to support the idea that coastal Douglas-fir has migrated in this same direction from ice-free refugia of the Wisconsin glaciation period. To confirm the latitudinal cline and the mode of inheritance of prodelphinidin in coastal Douglas-fir, additional populations should be analyzed and segregation data from known pedigrees should be obtained respectively.Résumé : La variabilité de six populations de sapin de Douglas (Pseudotsuga menziesii (Mirb.) Franco var. menziesii) a été étudiée à l'aide des flavonoïdes foliaires. Des deux proanthocyanidines et des six flavonols détectés et dosés par chromatographie liquide haute performance, la myricétine et la prodelphinidine permettent une séparation partielle des populations étudiées en trois groupes géographiques. Même si des différences substantielles ont été notées entre les populations situées aux deux extrémités nord et sud, les marqueurs flavoniques ont été insuffisants pour identifier, sans ambiguïté, l'origine d'une population de Douglas côtier. En accord avec d'autres marqueurs génétiques, il ne serait pas judicieux de reconnaître des races de Douglas côtier à l'intérieur de l'aire échantillonnée. D'un point de vue biogénétique, la synthèse de la prodelphinidine paraît gouvernée par un gène présent sous deux formes alléliques. Ces allèles sont différemment exprimés d'une population à l'autre de telle sorte qu'il existe un cline latitudinal de la prodelphinidine au sein de l'aire du Douglas côtier étudiée. La diminution progressive sud-nord en prodelphinidine serait le témoin de la migration du Douglas côtier dans le même sens méridien, et ce à partir de zones refuges constituées pendant la période glaciaire du Wisconsin. Afin de confirmer le cline latitudinal et le mode de transmission de la prodelphinidine chez le Douglas côtier, des populations supplémentaires doivent être analysées et des données de segrégation à partir de pedigrees conn...

Long‐term exposure to enhanced UV‐B radiation is not detrimental to growth and photosynthesis in Douglas‐fir

“…This may be a particular problem where, as in our study, sample sizes are small and the changes induced may be subtle. Indeed, variation in foliar flavonoids (UV‐absorbing compounds) has been used to quantify genetic variation in coastal Douglas‐fir (Kaundun et al. , 1998).…”

“…This may be a particular problem where, as in our study, sample sizes are small and the changes induced may be subtle. Indeed, variation in foliar flavonoids (UV-absorbing compounds) has been used to quantify genetic variation in coastal Douglas-fir (Kaundun et al, 1998). There is ample evidence to suggest considerable intraspecific variation in response to UV-B radiation in other tree species based upon differences in seed source (Sullivan & Teramura, 1992;Weih et al, 1998;Robakowski & Laitat, 1999).…”

Physiology and Growth of Containerized Coastal Douglas Fir Seedlings Given Different Durations of Short Days to Induce Dormancy

“…37°-53°N, lat. 119°-128°E) (Kaundun et al, 1998). Coastal douglas fir is very important to the economy of British Columbia because its wood is valued in the global market for high-quality structural lumber (Aubry et al, 1998).…”