Resumen

GUDINO, Whaleeha  y  DE LA BARRERA, Erick. Reproductive phenology and tolerance to high temperatures in Stenocereus queretaroensis. Polibotánica [online]. 2014, n.37, pp.63-78. ISSN 1405-2768.

Many cacti have edible fruits, so they have acquired an important role in agriculture in arid and semiarid regions, both for regional and international markets. Pitayas are the third most important cactus crop, after cactus pear and pitahaya. Reproductive phenology of Stenocereus queretaroensis requires specific conditions of temperature and precipitation, as well as the presence of pollinators to ensure fruit production. The production of buds, open flowers, and fruits was quantified from 2010 to 2012, it was the effect of high temperatures on floral tissues. There was an evaluated nectar production and concentration of solutes were measured on through the anthesis. The lethal temperature (LT₅₀) averaged 34.5 ± 0.4°C for the ovary and did not change between buds and flowers. In turn, petals of buds had an LT₅₀ of 21.5 ± 1.6°C, which was 33% higher. Reproductive development often requires the accumulation of certain amount of cold units. The tissues of young reproductive organs were better suited to withstand higher components than their mature counterparts.

Palabras llave : anthesis; flower buds; membrane permeability; minimum temperatures; nectar.