Evaluation of economically important traits from sixteen parental strains of the silkworm Bombyx mori L (Lepidoptera: Bombycidae) / Avaliação de características economicamente importantes de dezesseis linhagens do bicho-da-seda Bombyx mori L (Lepidoptera: Bombycidae)

The classification and characterization of silkworm strains are important for sericulture, which is supported by the constant development of new hybrids. In this study, 16 parental strains of Bombyx mori L from the germplasm banks of the Universidade Estadual de Maringá - UEM, and Associação dos Criadores de Bicho-da-Seda de Nova Esperança e Regiões Sericícolas do Paraná - ACESP, were evaluated regarding biological and productive traits economically important. The Chinese C122-B and C121-A, and the Japanese HA-A and HA-B strains yielded the highest cocoon weight, which is related to the raw silk percentage. Our data will be useful in breeding programs for the production of superior silkworm strains and hybrids.

A classificação e caracterização de linhagens de Bombyx mori L é importante para a sericicultura, uma vez que essa atividade é sustentada pelo constante desenvolvimento de novos híbridos da espécie. Neste trabalho, 16 linhages parentais de B. mori do banco de germoplasma da Universidade Estadual de Maringá - UEM, e da Associação dos Criadores de Bicho-da-Seda de Nova Esperança e Regiões Sericícolas do Paraná - ACESP, foram avaliadas em relação às características biológicas e produtivas consideradas economicamente importantes. As linhagens C122-B e C121-A, de origem Chinesa, e as HA-A e HA-B, Japonesas, apresentaram o maior peso de casulo (CW), o qual é associado ao teor de seda (RSP). Os resultados apresentados neste trabalho podem ser utilizados em vários programas de melhoramento visando à produção de linhagens e híbridos geneticamente superiores.

Simulation of germination of pioneer species along an experimental drought gradient.

The germination of ten plant species from the Iberian Peninsula was assessed along a water deficit gradient between -0. 1652 (moist) and -0.4988 MPa (dry) of osmotic potential, created by addition of increasing concentrations of polyethylene glycol (PEG 6000) to distilled water in which plants were grown hydroponically. The level and rate of germination of Daucus carota and Thapsia villosa significantly decreased with decreasing psi. Seeds of Dactylis glomerata and Dittrichia viscosa had positive germination responses to low osmotic potentials; germination of Epilobium hirsutum was not affected by osmotic potential. Germination of Medicago arabica, Cynosurus cristatus, Cistus ladanifer and Cistus albidus, was no favored by the addition of polyethylene glycol (PEG). Germination of Foeniculum vulgare and Thapsia villosa was inhibited by PEG.