Portal de Periódicos da CAPES

Dormancy and germination studies on mallow (Malva parviflora).

2004; Pontifical Catholic University of Chile; Volume: 31; Issue: 2 Linguagem: Inglês

10.7764/rcia.v31i2.289

0718-3267

Rodrigo A. Chorbadjian, Marcelo J. Kogan,

Plant Surface Properties and Treatments

Studies indicated that mallow seeds could be liberated from the fruit by soaking them in sulfuric acid (95%) during 2 h. These treatments did not affect seed germination at 90 days post harvest (DPH), but increased it slightly at 150 DPH. Due to the fact that only dorsal cuts of the seed coat with scalpel or needle puncturing, or chemical scarification allowed an increase in their germination, it was determined that M. parviflora seeds presented dormancy imposed by the seed coat. A higher germination rate was observed when the seed coat was cut (scalpel) than when it was punctured with a needle. Chemical scarification with sulfuric acid for 15 min to 4 h, allowed for approximately 90% germination of the seeds at 150 DPH, increasing the percentage of seeds damaged by the acid when treated up to 2 h. In the chemical scarification treatments, seeds that were scarified at 150 DPH germinated in higher percentages than those treated at 90 DPH. Studies carried out with seeds liberated of their fruit by acid treatments for 2 h and later scarified for 2 h with the same acid, were able to germinate with temperatures ranging from 3.4 to 33.3oC, with a peak in the germination rate between 16 and 24oC. Los estudios realizados, indicaron que las semillas de Malva parviflora podian ser liberadas del fruto mediante tratamientos de remojo en acido sulfurico (95%) durante 2 h. Estos tratamientos no afectaron la germinacion de semillas de 90 dias post cosecha (DPC), sin embargo, incremento la germinacion de semillas de 150 DPC. Dado que solo los tratamientos de escarificacion manual (corte dorsal de la testa con bisturi y puncion con aguja) y escarificacion quimica con acido sulfurico permitieron un aumento significativo de la germinacion, se considero que las semillas de M. parviflora presentan dormancia impuesta por la testa. Se observo una mayor tasa de germinacion cuando se corto parte de la testa con un bisturi, que cuando se perforo el dorso de la testa con una aguja. El proceso de escarificacion quimica con acido sulfurico entre 15 min y 4 h, permitio un 90% de germinacion de las semillas de 150 DPC. Sin embargo, a partir de 2 h de tratamiento el porcentaje de semillas danadas aumento. En los tratamientos de escarificacion quimica con semillas de 90 y 150 DPC, se observo un mayor efecto de los tratamientos sobre la germinacion de las semillas, cuando transcurrio mas tiempo desde su cosecha. Los estudios realizados con semillas de 150 DPC liberadas del fruto mediante tratamientos con acido sulfurico durante 2 h y posteriormente escarificadas por 2 h con el mismo acido, germinaron con temperaturas desde 3,4 hasta 33,3oC, presentando una temperaturaoptima para la germinacion entre 16 y 24oC.