Estimation of Performance and Genetic Parameters of Ten Chinese and Japanese Silkworm Hybrids in a Crisscrossing System
Subject Areas : Journal of Crop EcophysiologyS. Nematollahian 1 , M. Ghanipoor 2 , A.R. Seidavi 3 , S.Z. Mirhosseini 4 , M. Mavvajpour 5 , A.R. Bizhannia 6
1 - Iran Silkworm Research Center, Rasht, Iran
2 - Iran Silkworm Research Center, Rasht, Iran
3 - Staff Member of Rasht Branch, Islamic Azad University, Rasht, Iran
4 - Staff Member of Department of Animal Science, Faculty of Agriculture, University of Guilan, Rasht, Iran
5 - Iran Silkworm Research Center, Rasht, Iran
6 - Iran Silkworm Research Center, Rasht, Iran.
Keywords: Correlation, Hybrid, heritability, Silkworm, Crisscrossing System,
Abstract :
Performance of five Chinese commercial lines of silkworm like 32, 104, 110, 152, 154 and five Japanese ones such as 31, 103, 107, 151, 153 were investigated at four rearing periods of two spring and two summer seasons. Total hatch, rearing steps, recording and experimental activities were conducted under standard conditions of ESCAP (1993). The results indicated that maternal base effect all of effects in model (generation, genus and hybrid group) was significant (P<0.0001). Except for maternal base effect, other present ingredient in statistic model were extremely significant (P<0.0001) as compared with mean effects of all ingredients studied except the maternal base effect over characters cocoon weight, cocoon shell weight and cocoon shell percentage was significant (P<0.0001). Variance components estimated, by using one trait analysis method, showed that 153×154 and 31×32 hybrids had high heritability (0.8365 and 0.7848 for cocoon weight trait respectively). Thus, it could be said that rate of genetic gain from accomplishment of selection programs using from this hybrids for new lines production would be appreciable. Also it seems 153×154 despite its high heritability for individual traits (0.8365 and 0.9854 for cocoon weight and shell cocoon weight respectively) did have lower mean relative to 31×32 and this shown this hybrid may be sensitive to environmental conditions. The results obtained from estimation of genetic, environment and phenotypic correlations using two trait analysis methods is shown that the hybrid 153×154 had maximum additive genetic correlation. It can be concluded that hybrid 31×32 concerning most economical characters was superior.