Anthocyanins of jack pine (Pinus banksiana) seedlings

Purpling of the needles of jack pine seedlings in forest tree nurseries in the autumn is a result of the production of at least five anthocyanin pigments: cyanidin 3-O-glucoside (∼80%), delphinidin 3-O-glucoside (∼8%), peonidin 3-O-glucoside (∼8%), petunidin 3-O-glucoside (∼3%) and malvidin 3-O-glucoside (trace). The twigs subtending the needles also produce a similar range of pigments. The entire spectrum of pigments is produced from the time of the first exposure to freezing temperatures. Proanthocyanidins are a prominent feature of the needle phenolics and the question of their possible involvement in the purpling phenomenon following exposure to sub-zero temperatures is raised. The red colour of the hypocotyl of the newly germinated seedling is also a result of a similar mixture of pigments.