Caracterização de oito raças do bicho-da-seda (Bombyx mori L.)

Abstract

O experimento foi conduzido na Estação Experimental de Zootecnia de Gália, do Instituto de Zootecnia, SAA-SP, no ano de 2000. Oito raças de bicho-da-seda, de origem Japonesa e Chinesa foram estudadas (B101, B102, B104, B109, C201, C202, C203, C208) em relação a caracteres biológicos (Ganho de peso total de uma lagarta-GP, Porcentagem de mortalidade-MO, Número de machos-NM, Número de fêmeas-NF, Número de ovos/postura-OP e Porcentagem de eclosão-EC) e caracteres de produção de casulo (Peso unitário da glândula sericígena-GS, Peso de 30 cascas séricas-CS, Peso de 30 crisálidas-PC, Teor de seda líquido-TS, Casulos desclassificados-CD, Comprimento do casulo-CC e Largura do casulo-LC). O delineamento experimental foi o inteiramente casualizado, com quatro repetições/raça. Não houve variação entre as raças para GP, MO, NF e OP. A raça B101 apresentou, no geral, um menor NM e uma menor EC. Quanto à produção de casulos, no geral, os melhores resultados foram apresentados pela raça C202, com um bom GS (38% do peso final da lagarta), um dos mais altos CS e TS e valores próximos da média para PC, CD, CC e LC. A raça C201, em relação ao casulo produzido, apresentou os piores resultados.

Evaluation of economically important traits from sixteen parental strains of the silkworm Bombyx mori L (Lepidoptera: Bombycidae)

“…Strains C121-A, C209, M11-A, M18-2, and M102 showed the best performance when comparing the LBW and LBL obtained by 5 th instars (Table 2). However, only strains M11-A and M102 achieved higher values of SGW, contrary to what has been previously reported, as these parameters were indicated as correlates to predict the silkworm silk production capacity (Porto et al 2004).…”

“…However, Strains C121-A and C122-B generated lower values for SGW (Table 2), but exhibited the greatest values of RSP, indicating the silk gland development may be uneven among different strains, especially when 5 th instars were sampled earlier in their development. The CW (1.5 g), SW (0.4 g) and RSP (18.3%) mean values obtained for all 16 strains were higher than in some of the studies available in the literature (Porto & Okamoto 2003, Porto et al 2004, Rao et al 2006.…”

“…The mean value obtained for SGW corresponds to 16.5% of the larval body weight (LBW) (Fig 1), much lower than the 32-38% reported by Porto et al (2004), but in this case, seven to 8-day-old 5 th instars were analyzed instead. This time difference (two to three days) is important because the silk production is faster at the end of the 5 th instar, which can be refl ected in an increase in the SGW weight.…”

“…The SW and the SGW determine the potential for silk production because the energy for silk formation is contained within this gland (Porto et al 2004). However, Strains C121-A and C122-B generated lower values for SGW (Table 2), but exhibited the greatest values of RSP, indicating the silk gland development may be uneven among different strains, especially when 5 th instars were sampled earlier in their development.…”

Comparative Study of Biological Characters of Silkworm Eggs

“…In addition to help to maintaining the germplasm bank, these analyses are crucial in choosing the parents involved in the production of superior hybrids in breeding programs. Moreover, the biological performance of B. mori can reflect on maximum final silk production potential (Porto et al, 2004).…”