Evaluation of productive performance of 51 different peanut cocoon strains of Iran silkworm Bombyx mori (Lepidoptera: Bombycidae) germplasm

In our study, 51 peanut strains of Iran silkworm germplasm were evaluated for 36 economically important traits and for the feasibility of using these strains for breeding programs. After hatching of eggs, neonates were brushed and reared up separately on fresh leaves of mulberry (Morus alba). Newlyhatched larvae of all strains were reared for experiment. Individual egg laying were prepared for each strain before rearing and each individual egg laying consisted of about 500 eggs taken from one disease free laying and decreased to 250 larvae at the beginning of the 4th instar

Identification of AFLP markers linked with cocoon weight genes in silkworm (Bombyx mori L.)

DNA markers used in assisting selection method is a safe method in breeding process, due to deletion of environmental conditions, and it is an important tool in preparing linkage map and QTLs mapping. In mulberry silkworm that is, foundation of world sericulture, its major production-economic characteristics are polygenic. In this study, we want to determine QTL(s) affecting cocoon weight trait by AFLP markers. For this reason, we used 20 selected primer combinations from among 81 primers combinations of PstI/TaqI at the level of three F2 populations including 33, 36 and 34 offsprings sample, respectively. These populations were obtained by crossing two lines of Lemon Khorasan (as maternal) and 107 (as paternal). The parental lines, F1 and F2 individuals’ DNA were extracted with phenolchloroform method. Then they were digested by two restriction enzymes (TaqI and PstI) and amplified by using of appropriate adaptors. These amplified samples are transfered on annealed 6% polyacrylamide gels. After genotyping of individuals, the linkage maps of populations were drawn by Map manager/QTX and QTL Cartographer ver.2.5 softwares. Number of total and polymorphic bands that formed to 20 primer combinations in each populations were 930, 944, 810 and 142, 171, 178 bands, respectively. Therefore polymorphic frequencies were 15.27, 18.11 and 21.97%. The obtained linkage maps were included in 16, 18 and 24 linkage groups. The total length of this linkage maps and average distance between two markers were 2186.40, 2582.50 and 2392.60 cM, and 18.37, 16.45 and 14.95 cM, respectively. The detection of QTLs numbers of cocoon weight character in each F2 populations also showed 1, 6 and 1 loci in LRS>17 (LOD > 3.7) by compound interval mapping methods, respectively

Genetic diversity and classification of 51 strains of silkworm Bombyx mori (Lepidoptera: Bombycidae) germplasm based on larval phenotypic data using Ward’s and UPGMA methods

The aim of this experiment was to study and classify all 51 pure lines of Iran silkworm germplasm based on larval traits and identification of pure lines relationships. The average linkage between two groups is considered as the average of distance between all pairs of cases with one number from each group. Hierarchical clustering analysis was carried out by considering all studied parameters together. The grouping methods allowed the study to subdivide the observations into several subgroups in such a way that homogeneity was obtained inside the subgroups and heterogeneity among the subgroups. Various methods generated similar dendograms. On the basis of these dendrograms, analyzed strains were divided into 2 distinct groups. Frequent divisions were also observed in major groups. The first group was divided into two sub groups including three and eight strains, respectively. The second major group was divided into two sub groups which include 4 and 36 strains, respectively.Key words: Silkworm, unweighted pair-group method using arithmetic average (UPGMA), ward, cluster, gene bank, Iran

Selection indices for cocoon traits in six commercial silkworm (Bombyx mori L.) lines

Genetic parameters and economic values of cocoon traits in six commercial silkworm varieties (110, 107, 101433, Xinhong1, Koming1 and Y) were analyzed and selection indices for these traits were constructed. Cocoon weight, shell weight and shell ratio for each silkworm were carried out for four generations. Heritability and correlation coefficients were estimated by the REML method. Heritability of cocoon weight and cocoon shell weight were higher than the heritability of cocoon shell ratio. Using a deterministic model, the economic weights of the traits were calculated. In each variety, two conventional indices (family and individual indices), two restricted indices (family and individual restricted indices) and two base indices (individual and phenotypic base indices) were constructed. The expected economic efficiency resulting from family index selection was the highest. Thus, family index is suggested for selection. The maximum and minimum selection accuracy, expected economic gain and relative efficiency of individual to family index belonged to Xinhong1 and 107, respectively

Morphological and molecular identification of filamentous fungi isolated from cosmetic powders

Seven fungi were isolated from 50 samples of cosmetic powders. Morphological analyses and ribosomal DNA Internal Transcribed Spacers sequencing were performed which allowed the discrimination of the isolated fungi as Aspergillus fumigatus, Penicillium sp., and Cladosporium sp. which could have, among their species, potentially pathogenic microorganisms