Document Type : Research Paper
Authors
1 Corresponding Author, Iran Silk Research Center, Agricultural Research, Education and Extension Organization (AREEO), Rasht, Guilan, Iran. E-mail: ramin.abdoli.ramin.abdoli@gmail.com
2 Iran Silk Research Center, Agricultural Research, Education and Extension Organization (AREEO), Rasht, Guilan, Iran. E-mail: rezasourati@yahoo.com
3 Department of Animal Science, Faculty of Agricultural Sciences, University of Guilan, Rasht, Iran. E-mail: hosseini@guilan.ac.ir
4 Department of Agricultural Biotechnology, Faculty of Agricultural Sciences, University of Guilan, Rasht, Iran. E-mail: farjad.rafeie@guilan.ac.ir
Abstract
Introduction: Considering the importance of comparing the silkworm performances of Iranian and imported commercial hybrids from China production traits, viability index and cocoon dimensions index were investigated in eight Iranian (31×32, 32×31, 103×104, 104×103, 151×154, 154×151, 153×154 and 154×153), and nine imported Chinese commercial hybrids (Suju×Minghu (S×M), Minghu×Suju (M×S), Baiyue×Qiufeng (B×Q), Qiufeng×Baiyue (Q×B), BaiyueB×QiufengA (BB×QA), QiufengA×BaiyueB (QA×BB), 781×7532, Lianggang No2 and Guican No 5) in the present study.
Materials and Methods: After eggs hatched and according to the standard protocols, the studied hybrids were reared under the same conditions at Iran Silk Research Center (ISRC). Statistical analyses were done in three replications of 200 larvae (totally 600 records per each hybrid) based on completely randomized design. For comparing the means, Tukey's statistical test was used at a significance level of P<0.05. The GLM procedure was used in SAS software version 9.4. Data generated in respect of the studied traits were subjected for further analysis by a multiple trait evaluation index using the following formula: evaluation index (E.I.)= (A-B/C×10) + 50, where A is value of a particular breed for particular trait, B is mean value for a particular trait of all the hybrids, C is standard deviation of a particular trait for all the hybrids, 10 is standard unit and 50 is fixed value. Minimum / average Evaluation Index (E.I) value fixed for selection of a hybrid is >50. Based on the evaluation index (E.I) consisted of production traits and viability, best hybrids were identified.
Results and Discussion: The result of the research showed the close competition between Iranian and Chinese silkworm hybrids. In the situation that the performance of Iranian 32×31 and 31×32 hybrids for traits related to weight, shell weight and shell percentage of best cocoons was higher than the other hybrids but based on a composite index that was used in this research, 151×154, 154×151, 153×154 and 154×153 hybrids showed superiority. Based on this index, M×S and S×M as well as BB×QA and QA×BB had a higher average than the other hybrids. This result is based on the average of two-way crosses for the hybrids that both pairs were used in the experiment.
Conclusion: Generally, the results of mean comparisons and evaluation index showed that Iranian hybrids had better performance in all traits related to produce cocoons than the Chinese hybrids. Although, Chinese hybrids were significantly different from the Iranian for pupa viability percentage trait as Lianggang No2 hybrid showed the highest value.
Keywords