Potencial fisiológico de sementes de abóbora moranga (Cucurbita maxima) e caserta (Cucurbita pepo)

Abstract

Seed vigor tests allow to obtain additional information provided by the germination test, to obtain more consistent data over different field conditions. This study aimed to evaluate procedures and methodologies for testing seed vigor and to indicate those with sensitivity for identifying levels of vigor among lots of pumpkin seeds. The species Cucurbita maxima (Moranga) and Cucurbita pepo (Caserta) were used represented by four lots. Initial quality was verified by seed moisture content, mass of 1000 seeds and germination test. The vigor of the seeds was assessed using the first count of germination test, precocity of primary root emission, speed, speed ratio and mean germination time, Timson index, vigor classification, cool germination, seedling emergence, and the average speed of emergency, length and dry weight of seedlings, accelerated aging and electrical conductivity. In the precocity of primary root emission test, three and four days, were efficient to separate lots of Cucurbita maxima and Cucurbita pepo. For C. pepo, the cool germination rated lots similarly to emergency primary root test. For C. maxima, there was no difference in the length and seedling dry weight of different seed lots. For C. pepo the evaluations of seedling length when using the methodology proposed by ISTA provided appropriate separation among seed lots, this occurred also in electrical conductivity for this species. For the Pumpkin and Caserta seeds, the germination tests at low temperature, primary root protrusion at 3 and 4 days and seedling vigor classification were efficient in separating of lots based on the physiological potential.