Germination of Capsicum annuum L. at low temperature / by James Thomas Watkins.

Abstract

The cause of slow and nonuniform germination of pepper (Capsicum annuum L.) seeds at low temperature was investigated. There was no evidence of a Teachable or extractable germination inhibitor being activated or formed due to low temperature exposure. Auxin and kinetin applications did not effect germination rate. However, gibberellic acid (GA) treatments effectively increased germination rates at 15°a nd 25°C. Gibberellic acid 4+7 was more effective than GA 3. Gibberellic acid stimulated germination rate under osmotic stress and the presence of a GA synthesis inhibitor reduced germination rate. High oxygen (0 2) concentrations stimulated pepper seed germination rates at 25°C but inhibited germination rates at 15°. Gibberellic acid applications could not overcome the inhibitory effect of 100% 2 at 15. Seed respiratory activity was greater at 25°i n 100% 2 than in air, but the additional 2 did not alter respiratory pathways. At 15°, total respiration, respiravi loss of cellular integrity and endosperm thickness in front of the radicle. Gibberellic acid treatments stimulated endosperm breakdown. Pepper seed cell wall degrading enzyme activity increased with increased imbibition time, with temperature, and GA treatment. Pepper seed enzyme extracts preferentially degraded a galactomannan substrate but did not degrade a carboxymethylcellulose substrate indicating that manno-polysaccharides may be components of pepper seed endosperms.

A Estatística na escola básica: uma prática de inferência informal

“…Assim, esse recurso visual pode ser utilizado em diferentes níveis de aprendizado e explorado de acordo com o entendimento dos alunos com argumentos e relações cada vez mais sofisticados Watkins et aZ. (2001) Nesse mesmo sentido, ]x/machado (2009) evidencia que um mesmo objetivo pode ser atingido em diversos níveis de profundidade e com a mesma seriedade.…”