Four neotropical species of Vigna Savi (Leguminosae, Phaseolinae) have potential value as forage crops or ornamentals and could be cultivated in tropical or subtropical areas, even on floodplains. In order to obtain useful data for their culture and taxonomy, the seed morphology, germination pattern (hypogeal or epigeal) and seedling development were studied. The studied species belong to different sections of the genus: V. adenantha (G.F.W. Meyer) Maréchal, Mascherpa & Stainier (Sect. Leptospron); V. candida (Vell.) Maréchal, Mascherpa & Stainier (Sect. Sigmoidotropis); V. caracalla (L.) Verdc. (Sect. Caracallae) and V. luteola (Jacq.) Benth. (Sect. Vigna). The seeds were collected during fieldwork conducted in northwestern and northeastern Argentina. The qualitative and quantitative characters of the seeds were registered, after which they were sown. The development of the emerged seedlings was followed, first in a greenhouse and thereafter in open field. We recorded the type of germination, the thigmotropic movements of the hypocotyl and of the stem, seedling architecture and plant longevity. These traits allowed us to differentiate the species and construct an identification key that could be useful for agronomic or floricultural purposes. The data obtained partially support the current taxonomic treatment of the genus.

Passiflora has nearly 525 spp. with x = 9 or 6. A cytogenetic study of four species from subgenus Passiflora that grow in Argentina was performed. Giemsa technique, fluorescent chromosome banding CMA/DAPI and FISH (probe 18-5,8-26S and 5S) were used in mitotic chromosomes. P. caerulea, P. tucumanensis and P. cincinnata resulted diploid (2n = 18) while P. mooreana tetraploid (2n = 36). The karyotypes were highly symmetrical, with the formula 8 m+ 1 sm, duplicated in P. mooreana. With CMA/DAPI, diploids showed 2-3 pairs of terminal bands CMA + /DAPI - , whereas the tetraploid five bands, associated to NOR in all cases. With FISH, the loci 18-5.8-26S coincided in number and position with the CMA + /DAPI - bands. In each species, the number of sites for 5S rDNA genes agreed with the ploidy level. Data of P. tucumanensis and P. mooreana are here reported for the first time, being this last species the first known tetraploid for subgenus Passiflora. FISH patterns and heterochromatic bands varied among the Passiflora species studied, mainly with respect to the number and distribution of the signals.

Passiflora comprende alrededor de 525 especies con x = 9 ó 6. Se realizó un estudio citogenético de cuatro especies del subgénero Passiflora que crecen en la Argentina. Se utilizaron las técnicas de Giemsa, bandeo cromosómico fluorescente CMA/DAPI y FISH (sonda 18-5,8-26S y 5S) en cromosomas mitóticos. P. caerulea, P. tucumanensis y P. cincinnata resultaron diploides (2n = 18) mientras que P. mooreana, tetraploide (2n=36). Los cariotipos fueron altamente simétricos con la fórmula 8 m+ 1 sm, duplicada en P. mooreana. Con CMA/DAPI, todos los diploides presentaron dos o tres pares de bandas terminales CMA + /DAPI - , mientras que la especie tetraploide presentó cinco pares, asociadas a NOR. Con FISH, los loci 18-5,8-26S coincidieron en número y posición con las bandas CMA + /DAPI - . En cada especie, el número de sitios para los genes de 5S ADNr concordaron con el nivel de ploidía. Los datos de P. tucumanensis y P. mooreana se reportan por primera vez, siendo esta última el primer tetraploide conocido para el subgénero Passiflora. Los patrones de FISH y las bandas heterocrómaticas variaron entre las especies de Passiflora estudiadas, principalmente en el número y distribución de las señales.

The breeding system, the floral characteristics and the visitors of the polymorphic Passiflora suberosa were studied in different natural populations of Corrientes and Misiones provinces, and at a partially-opened greenhouse in Buenos Aires. The different reproductive indexes calculated evidenced that, although it is highly self-compatible, autogamy is partial. The reproductive efficiency was similar in the field and in the greenhouse. The major relative reproductive success obtained by induced self-pollination suggests that the reproductive output may be improved with the help of pollinations, either natural or artificial. Although the single flower and the blooming are inconspicuous, the floral characters may be involved in wasps attraction. The scarcity or even absence of pollinators (depending on the sites) seems to be compensated with the capacity of autogamy and the extended flowering period. The successful treatments performed in the greenhouse and the long period of time the fruits remain on the plants constitute stimulant features to cultivate this ornamental, medicinal, edible and tinctoreous species.

El sistema reproductivo, las características florales y los visitantes de la polimórfica P. suberosa fueron estudiados en distintas poblaciones naturales de las provincias de Corrientes y Misiones y en un invernáculo parcialmente abierto en Buenos Aires. Los distintos índices reproductivos calculados evidenciaron que, a pesar de que es altamente autocompatible, la autogamia es parcial. La eficacia reproductiva fue similar en el campo y en el invernáculo. El mayor éxito reproductivo relativo obtenido por autopolinización inducida sugiere que la reproducción puede ser mejorada con la ayuda de polinizaciones, ya sean naturales o artificiales. Aunque las flores por sí solas y la floración son inconspicuas, los caracteres florales pueden estar involucrados en la atracción de avispas. La escasez o incluso la ausencia de polinizadores (dependiendo de los sitios) parecen estar compensada con la capacidad de autogamia y el período extendido de floración. Los tratamientos fructíferos llevados a cabo en el invernáculo y el largo tiempo que los frutos permanecen en las plantas constituyen aspectos estimulantes para cultivar esta especie ornamental, medicinal, comestible y tintórea.