Environmental differences between sites control the diet and nutrition of the carnivorous plant Drosera rotundifolia

Background and aims: Carnivorous plants are sensitive to small changes in resource availability, but few previous studies have examined how differences in nutrient and prey availability affect investment in and the benefit of carnivory. We studied the impact of site-level differences in resource availability on ecophysiological traits of carnivory for Drosera rotundifolia L. Methods: We measured prey availability, investment in carnivory (leaf stickiness), prey capture and diet of plants growing in two bogs with differences in N deposition and plant available N: Cors Fochno (0.62 g m−2 yr.−1, 353 μg l−1), Whixall Moss (1.37 g m−2 yr.−1, 1505 μg l−1). The total N amount per plant and the contributions of prey/root N to the plants’ N budget were calculated using a single isotope natural abundance method. Results: Plants at Whixall Moss invested less in carnivory, were less likely to capture prey, and were less reliant on prey-derived N (25.5% compared with 49.4%). Actual prey capture did not differ between sites. Diet composition differed – Cors Fochno plants captured 62% greater proportions of Diptera. Conclusions: Our results show site-level differences in plant diet and nutrition consistent with differences in resource availability. Similarity in actual prey capture may be explained by differences in leaf stickiness and prey abundance

Reproductive biology of Sporobolus phleoides Hack. (Poaceae) an endemic phalophyte grass of Argentina

Sporobolus phleoides is an endemic grass of Argentina considered an important genetic resource for saline environments due to its salinity tolerance. Basic information about its reproductive biology is needed to adequately preserve its genetic variability. Hence, we studied its breeding system through phenology, embryological analysis, and self-pollination versus open-pollination treatments in six populations collected from four provinces of Argentina. The results indicated that S. phleoides is mainly autogamous with a high fertility rate. Cleistogamous and chasmogamous spikelets are isomorphic and occur simultaneously on the inflorescence, with higher percentages of cleistogamy found in the basal region of the panicle. The average percentage of cleistogamy during the study period was 23 % for all populations evaluated. The development of the embryo sac follows the typical pattern of grasses and indicates normal sexual reproduction. This study provides the basis for programming genotype collections for gene banks and future plans of domestication.Fil: Richard, Geraldina Alicia. Universidad Nacional del Litoral. Facultad de Ciencias Agrarias; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe; ArgentinaFil: Pensiero, Jose Francisco. Universidad Nacional del Litoral. Facultad de Ciencias Agrarias; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe; ArgentinaFil: Cerino, María Carolina. Universidad Nacional del Litoral. Facultad de Ciencias Agrarias; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe; ArgentinaFil: Galati, Beatriz Gloria. Universidad de Buenos Aires. Facultad de Agronomía; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Gutierrez, Hugo Francisco. Universidad Nacional del Litoral. Facultad de Ciencias Agrarias; Argentin