Respostas morfofisiológicas de plântulas de Vitex cymosa bertero ex spreng. (Lamiaceae) à inundação artificial

Abstract

Before the plants remain completely submerged, the seasonal flooding occurs gradually in the várzea floodplain forests of the Amazon. The adaptive features developed by the plants to cope with the anaerobic conditions caused by the flooding period may vary according to the species, flooding duration, plant age and water column height. Therefore, we evaluated in Vitex cymosa 1-year follow-up seedlings if there are differences in the early development of morpho-physiological and biochemical features according to the influence of different levels of water column. The seedlings (n=15 per treatment) were submitted to three treatments over 45 days: no flooding (everyday watered), gradual flooding (daily 5 cm water column increase till the total plant submersion at the 10º day) and abrupt flooding (sudden totalsubmersion). After the flooding, the seedlings were monitored within 60 days. Non-destructive parameters were evaluated, which encopassed height and diameter growth, analysis of the chlorophyll a fluorescence, leaf loss and production and destructive parameters which encopassed biomass, relative growth rates, stalk and leaf anatomy, starch content and total soluble sugar amount. Based on morpho-physiological, anatomy and biochemical analysis, the gradual inundation allowed the V. cymosa seedlings to a short acclimatization period to face the total submersion, which was not observed in the abrupt flooding