Shoot growth and development of Berberis buxifolia Lam. in Tierra delFuego (Patagonia)

Abstract

Knowledge on the annual cycle of growth and development of several fruit species from temperate climateis available; however, few reports exist on fruit shrubs from cold climates like those of Berberis genus. Theobjective of this work was to study the shoot growth and development of the native Patagonian speciesBerberis buxifolia Lam., whose black blue fruits are of economic value. Data were recorded from adultplants that were planted in a representative area located near Ushuaia city, 54◦48 SL, 68◦19 WL, (Tierradel Fuego, Argentina). Shoots grown during the growing season developed vegetative and mixed budsin their nodes. Vegetative buds differentiated numerous leaves distributed around the central axis withthe point of insertion nearly to the same height. In effect, when the bud sprouting starts, a rosette-likegrowth occurs. Flower differentiation started twelve weeks after bud breaks in coincidence with the endof the first fruit growth phase. In the following growing season, thirteen weeks later of sprouting, stamenprimordial and a single carpel could be shown. Gamete differentiation occurred in a short period beforesprouting for male gametes and during flowering time for female gametes. Blooming period occurredon spring and the length of the anthesis phase was closely related to the climatic conditions. While fruitgrowth followed a double sigmoid curve, shoot elongation showed a sigmoid curve. Knowledge of shootgrowth and development of B. buxifolia is of great importance to understand its physiology, and whenculture practices need to be incorporated like plant fertilization or when evaluating the impact of adverseclimatic conditions on events as flowering and fruit set.