Diego Miranda

Importancia y cultivo de la uchuva (Physalis peruviana L.)

Physalis perurvianus L, foi adaptada no Peru e Chile e dai levada para outros paises da America Latina, incluindo Brasil alem da India, Africa do Sul e outros. Neste trabalho sao discutidas informacoes sobre seu cultivo em varios paises, importancia economica, aspectos botânicos, propagacao, doencas e pragas e pos-colheita.

Salinity effects on proline accumulation and total antioxidant activity in leaves of the cape gooseberry (Physalis peruviana L.)

The effect of increasing sodium chloride (0, 60 and 120 mM NaCl) stress was investigated on the growth, proline content and total antioxidant activity (TAA) in leaves of cape gooseberry plants grown under greenhouse conditions. Plants were cultivated in 2 L pots and supplemented with nutrient solution for 75 days. Plant leaves were analyzed 45, 55, 65 and 75 days after transplanting. The vegetative growth (measured as total plant and organ dry weight [DW], leaf number and leaf area, as well as plant height) was significantly lower at 120 mM NaCl. At 60 mM NaCl, all determined leaf parameters and total plant DW were markedly reduced compared to non-salinized plants. Leaf proline content increased during the period of evaluation, being between two- and three-fold higher in plants at the 120 mM NaCl level compared to control plants. TAA, measured as µM Fremys salt per g-1 FW, increased constantly during the evaluation period and from day 55 was significantly higher than in leaves of non-salinized plants. After 75 days of salt stress, both TAA and proline content did not differ between the 60 and 120 mM NaCl treatments. For all sampling dates, the 120 mM salt concentration significantly enhanced free radical scavenging activity compared to control and the 60 mM NaCl treatment. All treatments showed a nearly 12% increase in the radical scavenging activity during the experiment’s duration.

Temperatura de germinación de semillas de anón (Annona squamosa L.)

La propagacion sexual del anon es el metodo mas utilizado por los productores en Colombia, sin embargo uno de los problemas del cultivo es la baja e irregular germinacion de las semillas. En esta investigacion se busco establecer la temperatura optima de germinacion de semillas de A. squamosa L. Esta se realizo en el laboratorio de Fisiologia Vegetal, Facultad de Agronomia, Universidad Nacional de Colombia, semillas de accesiones de Apulo (Cundinamarca) y Castilla (Tolima) fueron puestas a germinar en turba rubia humeda sin nutrientes en un fitotron (humedad relativa de 60%, sin luz) durante 30 dias, en dos regimenes de temperatura constante: 30 y 35°C y dos regimenes de temperatura alterna: 30/20°C y temperatura ambiente (media: 18,7°C; maxima: 22,9°C; minima: 17,3°C). Se evaluo la respuesta de las variables porcentaje de germinacion (PG) cada 5 dias durante 1 mes y los indices sincronia de germinacion (E), tiempo medio de germinacion (TMG) y velocidad media de germinacion (VMG) al finalizar el ensayo. El maximo porcentaje de germinacion se obtuvo a una temperatura constante de 35°C para las semillas provenientes de Cundinamarca como del Tolima (58% y 57%, respectivamente), igualmente a esta temperatura se observo un menor TMG (18,41 dias para Cundinamarca y 17,09 dias para Tolima), una mayor VMG (0,035 y 0,040 semillas germinadas/dia para Cundinamarca y Tolima, respectivamente) y un indice de sincronizacion mas bajo (0,29 y 0,33 para Cundinamarca y Tolima, respectivamente), lo que sugiere como temperatura optima 35°C para la germinacion de las semillas de A. squamosa. Temperatura de germinacion de semillas de anon (Annona squamosa L.)

Effect of GA3, KNO3, and removing of basal point of seeds on germination of sweet granadilla (Passiflora ligularis Juss) and yellow passion fruit (Passiflora edulis f. flavicarpa)

Passiflora seeds germinate erratically presenting difficulties for their handling in a greenhouse. The effect of removing of basal point of seeds (RB) and pre-imbibition of seeds of sweet granadilla and yellow passion fruit in 50, 100, 200, and 400 mg mL -1 solutions of gibberellic acid (GA 3 ) or 0.1% KNO 3 solution was studied. The experiment was conducted in greenhouses in La Plata, Colombia. Two accessions PrJ1 and PrJ2 of sweet granadilla were evaluated. There were calculated the final percentage of germination (PG), mean germination time (MGT), and the mean germination rate (MGR). The leaf area and dry mass of seedlings were measured 22 days after sowing (das); with this data, specific leaf area and relation root/ shoot were calculated. In all cases, the highest germination percentages were achieved treating seeds with KNO 3 (89, 92, and 87% for yellow passion fruit, PrJ2, and PrJ1, respectively), but the increase in MGR (3.3 germinated seeds per day) and the decrease in MGT (16 days) were only significant for PrJ1. RB had a significant reduction of PG in all cases (28, 12, and 33% for passion fruit, PrJ2 and PrJ1, respectively). With the increase in the concentration of GA 3 , PG was reduced for two accessions of sweet granadilla, for yellow passion fruit this trend was not clear, no treatment with GA 3 showed significant differences with the control. Leaf area (24.07 cm2) and dry mass of seedlings (135 mg) were significantly higher than seeds previously treated with KNO 3 only for PrJ1.The solution of KNO 3 0,1% is recommended to improve the germination and initial growth of granadilla seedlings. Index terms: Pre-imbibition, final percentage of germination, mean germination time, mean germination rate, leaf area.