یوسف خیرخواه رحیم آباد

Considering the production of new silkworm hybrids by prominent countries in the sericulture industry such as China and the import of these hybrids to the country in recent years, it is necessary to update these evaluations so that correct decisions can be made to choose the most suitable type of hybrid in terms of functional traits. Therefore, such comparisons are done annually and the results are sent to the Iran Sericultural Corporation- Silk Worm Research Center as an executive body for final decision. The present study aimed to investigate the performance of eight Chinese commercial silkworm hybrids, including Suju×Minghu (S×M), Minghu×Suju (M×S), Baiyue×Qiufeng (B×Q), Qiufeng×Baiyue (Q×B), BaiyueB×QiufengA (BB×QA), QiufengA×BaiyueB (QA×BB), 874×873, and 874×873. Hybrids 872×871 and 872×871 also were among the studied hybrids, but due to the decrease in the performance of cocoon-related traits compared to other hybrids that had a big difference in terms of the obtained values, they were removed and excluded from the final analysis. The desired hybrids for 14 traits including best cocoons weight produced per 26,000 larvae (BCW), total cocoons weight produced per 26,000 larvae (TCW), number of cocoons per liter (NCPL), weight of cocoons per liter (WCPL), percentage of pupa viability (PPV), mean weight of a cocoon (MWC), mean weight of a cocoon shell (MWCS), mean of cocoon shell percentage (MCSP), mean weight of a male cocoon (MWMC), mean weight of a male cocoon shell (MWMCS), mean of male cocoon shell percentage (MMCSP), mean weight of a female cocoon (MWFC), mean weight of a female cocoon shell (MWFCS), and mean of female cocoon shell percentage (MFCSP) were reared in the spring of 2022 after hatching and according to standard methods and under the same conditions in Iran Silk Research Center and their performance was recorded. Each silkworm hybrid was reared in three replications of 200 larvae (total number of observations including 600 records per hybrid for all traits) in a completely randomized design. The analysis of the obtained data was done by SAS software by using the procedure of generalized linear model (GLM), and the average performance of the traits was compared to each other using Tukey's range test at the probability level of P<0.05. The results of the analysis of variance for the studied traits showed that the effect of the hybrid type for most of the studied traits including best cocoons weight produced per 26,000 larvae (BCW), total cocoons weight produced per 26,000 larvae (TCW), number of cocoons per liter (NCPL), the weight of cocoons per liter (WCPL), mean weight of a cocoon (MWC), mean weight of a cocoon shell (MWCS), mean of cocoon shell percentage (MCSP), mean weight of a male cocoon (MWMC), mean weight of a male cocoon shell (MWMCS), mean of male cocoon shell percentage (MMCSP), mean weight of a female cocoon (MWFC), mean weight of a female cocoon shell (MWFCS) and mean of female cocoon shell percentage (MFCSP) was significant (P<0.05). In the meantime, only traits of the percentage of pupa viability (PPV) as the most important index related to survival and the mean of male cocoon shell percentage (MMCSP) were not affected by the hybrid type (P<0.05). The average performance of the hybrids showed a significant difference (P<0.05) for all the traits except for the percentage of pupa viability (PPV) and the mean of cocoon shell percentage (MCSP). The BB×QA hybrid showed a higher performance than other hybrids for six traits including the best cocoons weight produced per 26,000 larvae (BCW), the total cocoons weight produced per 26,000 larvae (TCW), the weight of cocoons per liter (WCPL), the mean weight of a cocoon (MWC), the mean weight of a male cocoon (MWMC), and the mean weight of a female cocoon (MWFC) (P<0.01). Also, the M×S hybrid showed a higher performance than other hybrids for the five traits of the mean weight of a cocoon shell (MWCS), mean of cocoon shell percentage (MCSP), mean weight of a male cocoon shell (MWMCS), mean weight of a female cocoon shell (MWFCS), and the mean of female cocoon shell percentage (MFCSP) (P<0.05). In addition, the M×S hybrid showed the lowest value compared to other hybrids for the number of cocoons per liter (NCPL), which the lower values of this trait are preferred (P<0.01).  Based on the results of the present research, the priority of importing and rearing silkworm eggs in 2023 is suggested for BB×QA and M×S hybrids. Although the performance of these two hybrids with other hybrids, except for the 874×873 and 874×873 hybrids, is not significant in most of the examined traits, they can still be considered as next-import priorities. The desired hybrids for 14 traits including: best cocoons weight produced per 26,000 larvae (BCW), total cocoons weight produced per 26,000 larvae (TCW), number of cocoons per liter (NCPL), weight of cocoons per liter (WCPL), percentage of pupa viability (PPV), mean weight of a cocoon (MWC), mean weight of a cocoon shell (MWCS), mean of cocoon shell percentage (MCSP), mean weight of a male cocoon (MWMC), mean weight of a male cocoon shell (MWMCS), mean of male cocoon shell percentage (MMCSP), mean weight of a female cocoon (MWFC), mean weight of a female cocoon shell (MWFCS) and mean of female cocoon shell percentage (MFCSP) were reared in the spring of 2022 after hatching and according to standard methods and under the same conditions in Iran Silk Research Center and their performance was recorded. Each silkworm hybrid was reared in 3 replications of 200 larvae (total number of observations including 600 records per hybrid for all traits) in a completely randomized design. The analysis of the obtained data was done by SAS software (version 9.4) by using the procedure of generalized linear models (GLM) and the average performance of the traits was compared to each other using Tukey's range test at the probability level of P<0.05. The results of the analysis of variance for the studied traits show that the effect of the hybrid type for most of the studied traits including best cocoons weight produced per 26,000 larvae (BCW), total cocoons weight produced per 26,000 larvae (TCW), number of cocoons per liter (NCPL), the weight of cocoons per liter (WCPL), mean weight of a cocoon (MWC), mean weight of a cocoon shell (MWCS), mean of cocoon shell percentage (MCSP), mean weight of a male cocoon (MWMC), mean weight of a male cocoon shell (MWMCS), mean of male cocoon shell percentage (MMCSP), mean weight of a female cocoon (MWFC), mean weight of a female cocoon shell (MWFCS) and mean of female cocoon shell percentage (MFCSP) is significant (P<0.05). In the meantime, only traits of the percentage of pupa viability (PPV) as the most important index related to survival and the mean of male cocoon shell percentage (MMCSP) were not affected by the hybrid type (P<0.05). The average performance of the hybrids showed a significant difference (P<0.05) for all the traits except for percentage of pupa viability (PPV) and the mean of cocoon shell percentage (MCSP). The hybrid BB*QA showed a higher performance than other hybrids for six traits including the best cocoons weight produced per 26,000 larvae (BCW), the total cocoons weight produced per 26,000 larvae (TCW), the weight of cocoons per liter (WCPL), the mean weight of a cocoon (MWC), the mean weight of a male cocoon (MWMC) and the mean weight of a female cocoon (MWFC) (P<0.01). Also, the M*S hybrid showed a higher performance than other hybrids for the five traits of mean weight of a cocoon shell (MWCS), mean of cocoon shell percentage (MCSP), mean weight of a male cocoon shell (MWMCS), mean weight of a female cocoon shell (MWFCS), and the mean of female cocoon shell percentage (MFCSP) (P< 0.05). Also, the M*S hybrid showed the lowest value compared to other hybrids for the number of cocoons per liter (NCPL); the lower values of which are preferred (P<0.01). Based on the results of the present research, the priority of importing and rearing silkworm eggs in 2023 is suggested for BB*QA and M*S hybrids. Although the performance of these two hybrids with other hybrids, except for the 874×873 and 874×873 hybrids, is not significant in most of the examined traits, and they can still be considered as next import priorities.

Microplastics (MPs) have been reported as emerging contaminants. There was little information about their effect and behavior on soil properties. This study aimed to investigate the changes in exchangeable concentrations (extracted with 1 M ammonium acetate) and water-soluble (ratio of 1 to 2.5 soil to water) of sodium (Na), potassium (K), calcium (Ca), and magnesium (Mg) elements under the presence of Low-Density Polyethylene MPs particles in the soil. The experiment was performed as a factorial experiment based on a completely randomized design with three replications. Experimental factors included the amount of MPs particles (zero, 1, 2, and 4% w/w) and incubation time (3, 17, 31, 45, 90, and 180 days). The results showed that MPs particles affected exchangeable and water-soluble elements. MPs particles reduced the exchangeable amounts of Na, K, and Ca. The largest decrease was related to the level of 4% MPs. Briefly. In the level of 4%, the amount of exchangeable Na, K, and Ca decreased by 7.2, 5.7 and 2.6 %, respectively, in comparison with control soil (without MPs). On the other hand, water-soluble K and Ca under the influence of MPs particles (4% MPs level) decreased by 6.97 and 8.4 % respectively, as compared with control. MPs particles reduced water-soluble Na in the first (3 days) to fourth (45 days) incubation periods. Also, MPs particles reduced the amount of exchangeable and water-soluble Mg, but it was not significant. In summary, the presence of MPs particles in the soil, especially in higher amounts (ex: 4%), can affect the availability of cationic elements such as Na, K, Ca, and Mg.

The mulberry tree can grow in a variety of climates. Mulberry leaf is a food of silkworm and plays an essential role in silk production. Therefore, improving the quality and quantity of mulberry leaves is very important in terms of silk production. The aim of this study was to investigate the effect of growth-promoting bacteria and municipal waste compost on morphological and physiological characteristics of mulberry tree. To conduct this research, 27 mulberry seedlings were prepared from the National Silk Research Institute. This research was conducted as a randomized complete block design with three replications. The treatments used included two levels of municipal waste (2 and 4 percent), two levels of Pseudomonas (106 and 5×106 cells per gram of soil) and control. Some physiological properties such as phosphorus, nitrogen, potassium, protein and sugar were measured in the leaves. Also, some morphological characteristics of the plant including fresh weight, leaf area index, specific leaf area, leaf length, etc. were measured. The results showed that the highest amount of protein and leaf area in the combined treatment of the second level of compost and bacteria were 22.57% and 2005 mm2, respectively. The results showed that with increasing the amount of compost and bacteria in the soil, leaf quality increased significantly physiologically and morphologically. In general, the results showed that the combination of organic and bio-fertilizers can be used instead of chemical fertilizers to provide the elements needed by the mulberry plant.

The present study was conducted by comparing the production capacity of six domestic commercial hybrids with 14 imported commercial. In this study, 3 replications included half gram from the beginning of egg hatching were placed in hatchery envelopes. Considering the same breeding site, the best commercial hybrids in terms of yield can be identified and introduced. This experiment was conducted in a completely randomized design and data under Graphpad Prism and Minitab were analyzed. The analyses were performed using ANOVA and differences between means were examined using the Tukey test. According to the results, 872*871 and 103*104 hybrids were the best population hybrids with about 98.5% hatching (p < 0.05). The total weight of the cocoon obtained in hybrids with Q*B 9/667 and L*OR and QA*BB with 663 grams were in the top group (p < 0.05). The results showed that the average cocoon shell weight in hybrids 872*871, 154*153, S*M and 103*104 in the group, had a significant increase (p < 0.05). In the case of cocoon production for 10,000 larvae, 153*153, 872*871 and S*M hybrids had the best cocoon production, respectively (p < 0.05). Specifically, the number of cocoons per liter was S*M and 872*871 hybrids with the lowest number of cocoons per liter as the best group in this trait. The overall conclusion of this study shows that domestic hybrids in many economic traits in silkworm breeding are or better than imported hybrids and can be used as a suitable alternative in this industry in Iran.