Search

The impact of antibiotics on growth, cocoon production was assessed in addition to isolation and characterization of bacteria associated with silkworm gut of infected larvae. Larval rearing was maintained at recommended conditions of temperature and humidity. Silkworm larvae showing abnormal symptoms were collected from the control group and dissected for gut collection. Bacteria were isolated from the gut content by spreading on agar plates and incubated at 37 °C for 48 hrs. Bacterial identification and phylogenetic analysis were carried out by 16S rRNA gene sequencing. The isolated bacteria were subjected to antimicrobial susceptibility test (disc diffusion methods) by using Penicillin (10 µg/mL), Tetracycline (30 µg/mL), Amoxicillin (25 µg/mL), Ampicillin (10 µg/mL), and Erythromycin (15 µg/mL). All isolated strains showed positive results for the catalase test. We isolated and identified bacterial strains (n = 06) from the gut of healthy and diseased silkworm larvae. Based on the 16S rRNA gene sequence, isolated bacteria showed close relation with Serratia, Bacillus, and Pseudomonas spp. Notably, 83.3% of strains were resistant to Penicillin, Tetracycline, Amoxicillin, Ampicillin, and Erythromycin but 16.6% showed antibiotic susceptibility to the above-mentioned commonly used antibiotics. Silkworm larvae fed on penicillin-treated leaves showed significant improvement in larval weight, larval length, and cocoon production. Significantly higher larval weight (6.88g), larval length (5.84cm), and cocoon weight (1.33g) were recorded for larvae fed on leaves treated with penicillin as compared to other antibiotics. Isolated bacterial strains showed close relation with Serratia spp., Bacillus spp. and Pseudomonas spp.

Mulberry (Morus spp.) is an important crop in the sericulture industry, as the leaves constitute the primary feed for the silkworm. The availability of diverse genetic sources of resistance to root-knot nematode (RKN; Meloidogyne spp.) are very scanty. To address this need, a set of 415 varied exotic and indigenous germplasm accessions were screened under glasshouse conditions. Twenty-one accessions were identified as highly resistant and 48 were resistant, with the highest numbers of highly resistant/resistant accessions being found in Morus alba. Further, 30 accessions based on rooting ability were evaluated for field resistance at four different locations with infested soil. Finally, eight germplasm accessions (BR-8, Karanjtoli-1, Hosur-C8, Nagalur Estate, Tippu, Calabresa, Thai Pecah, and SRDC-3) were identified as potential genetic sources in RKN-resistance breeding programs or as resistant rootstock for the establishment of mulberry gardens. Sixteen simple sequence repeat markers analyzed among the 77 resistant and susceptible accessions generated 55 alleles, ranging from two to five, with an average of 3.43 alleles per locus. Principal coordinates analysis grouped the accessions on the basis of susceptibility and resistance to RKN infestation. The RKN-susceptible accessions exhibited higher variability as compared with resistant accessions, and they were more dispersed. Analysis of molecular variance showed maximum molecular variance was 78% within the population, and 22% between populations. Results of this study indicate that simple sequence repeat markers are reliable for assessing genetic variability among the RKN-resistant and RKN-susceptible mulberry accessions.

Sericulture is an allied agricultural activity. It is concerned with the production of silk (and its byproducts). The silks produced in sericulture can be widely categorized as Mulberry silks and Non-Mulberry silks (also called Vanya silk meaning wild silks). Mulberry silk is most widely produced and it plays an essential role in the economic growth of the industry. Mulberry silk is obtained by rearing mulberry silkworms (Bombyx mori L). During rearing, they are fed mulberry leaves which are obtained from the mulberry plants; the primary food plant of the silkworm. The mulberry plant is perennial in nature. It belongs to the Moraceae family and the genus Morus with a wide variety of species, viz. Morus alba, Morus nigra, Morus serrata, etc. Mulberry plants are widely distributed all around the world in Tropical, Subtropical, and Temperate regions. It finds its early roots in Southeast Asia. The Mulberry plant falls prey to many diseases caused by various organisms like bacteria, viruses, fungi, and nematodes. The occurrence and severity of the diseases vary with season, varieties, agro-climatic zones, and the cultural practices that are undertaken. These diseases affect the mulberry leaves, stems, and different parts of the plant. Affected plants stop the growth and reduced leaf yield. As well as, these leaves are not suitable for silkworm feeding. This review mainly focuses on infectious diseases (fungal, bacterial, viral, and nematode) of mulberry plants and their management.

Beauveria bassiana is a harmful pathogen to the economically important insect silkworm, always causes serious disease to the silkworm, which results in great losses to the sericulture industry. In order to explore the silkworm (Bombyx mori) response to B. bassiana infection, differential proteomes of the silkworm responsive to B. bassiana infection were identified with isobaric tags for relative and absolute quantitation (iTRAQ) at the different stage of the 3rd instar silkworm larvae. Among the 5040 proteins identified with confidence level of ≥95 %, total 937 proteins were differentially expressed, of which 488 proteins were up-regulated and 449 proteins were down-regulated. 23, 15, 250, 649 differentially expressed proteins (DEPs) were reliably quantified by iTRAQ analysis in the B. bassiana infected larvae at 18, 24, 36, 48 h post infection (hpi) respectively. Based on GO annotations, 6, 4, 128, 316 DEPs were involved in biological processes, 12, 5, 143, 376 DEPs were involved in molecular functions, and 6, 3, 108, 256 DEPs were involved in cell components at 18, 24, 36, 48 hpi respectively. KEGG pathway analysis displayed that 18, 12, 210, 548 DEPs separately participated in 63, 35, 201, 264 signal transduction pathways at different time of infection, and moreover a higher proportion of DEPs involved in metabolic pathways. The cluster analysis on the DEPs of different infection stages distinguished a co-regulated DEP, lysozyme precursor, which was up-regulated at both the mRNA level and the protein level, indicating that the lysozyme protein kept playing an important role in defending the silkworm against B. bassiana infection. This was the first report using an iTRAQ approach to analyze proteomes of the whole silkworm against B. bassiana infection, which contributes to better understanding the defense mechanisms of silkworm to B. bassiana infection and provides important experimental data for the identification of key factors involved in the interaction between the pathogenic fungus and its host.

Mulberry (Morus indica L.) is a foliage crop cultivated extensively in the North-Eastern India under rainfed condition for rearing silkworm (Bombyx mori L.). An attempt was made through field exper...

The production of high-quality silkworm silk is of importance in sericulture in addition to the production of biomass, silk proteins, and animal feed. The distinctive properties of nanomaterials have the potential to improve the development of various sectors including medicine, cosmetics, and agriculture. The application of nanotechnology in sericulture not only improves the survival rate of the silkworm, promotes the growth and development of silkworm, but also improves the quality of silk fiber. Despite the positive contributions of nanomaterials, there are a few concerns regarding the safety of their application to the environment, in humans, and in experimental models. Some studies have shown that some nanomaterials exhibit toxicity to tissues and organs of the silkworm, while other nanomaterials exhibit therapeutic properties. This review summarizes some reports on the biological effects of nanomaterials on silkworm and how the application of nanomaterials improves sericulture.

Morus indica (L.) commonly known as Indian mulberry belonging to the family Moraceae is a fast growing perennial plant and is the primary food plant for the monophagous insect Bombyx mori has a special significance in the sericulture industry. Medicinal properties of this plant have been depicted in the ancient literature of Ayurveda. Some of the ayurvedic preparations use fruits, leaves, roots, bark or latex of the mulberry plant as potential treatment aid against various diseases. Because of the presence of several bioactive compounds like steroids, phenolics, alkaloids, reducing sugars, tannins, flavonoids, anthocyanins, terpenoids, cardiac glycosides, saponins, proteins, amino acids, carbohydrates etc., it is traditional being used as natural medicine for- anti-bacterial, anti-fugal, anti-hyperglycaemic, anti-hypoglycaemic, anti-hypolipidemic, hepatoprotective, anti-diabetic, anti-cancer, anti-pyretic, high antioxidant, and anti-inflammatory properties. The present review reveals the wide range of important uses of Indian mulberry including its phytochemical composition, antioxidants and medicinal properties and management towards human diseases.

Entomophagy is a re-emerging terminology used to describe the practice of consuming insects as a source of nutrition by human beings. In present study 4-6 days old silk cocoons were procured, pupae were collected and subjected for drying at 70oC for 48 hours, grounded and defatted (N hexane). Protein (crude) was extracted by acid- alkali pH (5.7) shift method. The results revealed that, dried pupae consist of 38.13% of protein, the true protein content of crude protein was 81.02%. proximate (AOAC), colour, water activity, protein solubility were analysed and characterized by analysing functional properties viz., water absorption capacity (3.08 0.02 gwater/gDM), oil absorption capacity (4.05 0.03 goil/gDM), emulsifying activity (1.93 0.09%), emulsifying stability (1.85 0.108%), foaming capacity (7.67 0.47%), foaming stability (5.83 0.23%) least gelation capacity (10.67 0.94w/v), bulk density (0.38 0.01g/ml) and tap density (0.46 0.008g/ml). Silkworm pupae protein proved to be cheap, edible and alternative protein source obtained as a by-product from sericulture industry.

Lipids have been recently proposed as key molecules for virus entry and egress, and lipid biosynthesis and signaling were reported necessary for some viruses during replication and infection. The silkworm Bombyx mori is an important economic insect and a model organism, but its lipid profiles have not been systematically investigated. Most silkworm strains are susceptible to the B. mori nuclear polyhedrovirus (BmNPV), a baculovirus that causes serious loss to the sericulture industry. Previously, our lab has screened a natural mutant of B. mori that is highly resistant to BmNPV. In this study, a comprehensive lipidomic analysis by ultrahigh pressure liquid chromatography-mass spectrometry (UPLC-MS) was carried out on the BmNPV-susceptible strain 306 and resistant strain NB (data deposited in MetaboLight MTBLS2142). Comparisons of the lipid profiles between the two strains reveal that phosphosphingolipids, diacylglycerolipids, ceramides, and quinones were present at notably higher levels in the susceptible strain, while lysophosphocholines were found at a higher level in the resistant strain. BmNPV administration changed the lipid profiles in both strains, revealing key lipids involved in virus infection and immune response. Some key enzymes in the lipid biosynthesis pathway were analyzed for their activities in the two silkworm strains and their virus-administered counterparts, underlining the relation among lipid biosynthesis, viral resistance, and immune response in the host.

The white mulberry (Morus alba L.) is particularly valued in Asia and Europe because its leaves serve as fodder for the mulberry silkworm (Bombyx mori L.) in the production of raw silk (sericulture). However, the health of silkworm caterpillars producing silk fibres, and the quality of their cocoons depend strongly on fodder quality. Moreover, this plant is also valuable in the food and pharmaceutical industries, where high-quality herbal material is required. In one of the Polish mulberry plantations, trees with chlorotic, angular leaf spots and blotches were observed. The disease multiplied in spring in humid conditions and spread to developing blossoms and leaves. Leaves were collected during two growing seasons (2017–2018) from 18-year-old trees cultivated at the Experimental Farm of the Institute of Natural Fibres and Medicinal Plants in Petkowo, Poland (52°12′40″N 17°15′31″E). Leaf lesions exhibited bacterial streaming, and bacterial colonies were readily isolated on tryptic soy agar. Biochemical (Biolog Gen III system v. 2.8.0), molecular (16S rDNA and gyrB genes), and pathogenicity testing in the greenhouse identified the causal agent as Pseudomonas syringae. This bacterial species was the most abundant in each of the sample tested. To our knowledge this is the first description and characterization of P. syringae affecting mulberry trees not only in Poland but throughout Europe. Our aim was to point out the importance of plant diseases caused by bacteria. This finding serves as a warning for the phytosanitary services in Europe and for the sericulture industry that a new disease threat has appeared for European mulberry crops.

The present studies on the evaluation of different bivoltine silkworm (Bombyx mori L.) breeds on survival against Nuclear Polyhedrosis Virus (Grasserie), under temperate climatic conditions was carried out at College of Temperate Sericulture, SKUAST-Kashmir, Mirgund. Preliminary evaluation of ten silkworm genotypes viz., APS4, APS8, CS6, CSR2, CSR4, DUN-6, DUN-22, NB4D2, SH6 and SANISH8 revealed that APS8 and NB4D2 breed possessed highest tolerance while, CSR2 and CSR4 were highly susceptible to BmNPV Inoculation @ 20,000 PIB’S. The silkworm CSR4 showed drastic decrease in survival rate of (37.33%) in susceptible breed. However in tolerant breed APS8 recorded the survival rate of (72.67%). The maximum pupation rate of 91.36 per cent was recorded in case of NB4D2 and minimum pupation rate of 82.41 per cent was recorded in CSR2.

Article Details: Received: 2020-02-23 | Accepted: 2020-04-08 | Available online: 2020-06-30 https://doi.org/10.15414/afz.2020.23.02.85-93 This study is aimed at proposing mulberry sericulture as an alternative to strengthen the agricultural economy of Hooghly district of West Bengal, India. Exploration of four breeds of mulberry silkworm, Bombyx mori (Linnaeus, 1758), popular in West Bengal (viz., two multivoltine breeds – Nistari Plain and Nistari Marked, One Bivoltine breed – SK6 X SK7 hybrid and one F1 Hybrid from cross between Nistari Plain and SK6 X SK7 hybrid) have been conducted in the Sericulture Research Laboratory, Post Graduate department of Zoology, Hooghly Mohsin College, Chinsurah, Hooghly, West Bengal, India, for three consecutive years (2016-2019) for various rearing parameters (viz., larval duration, matured larval weight, cocoon weight, shell weight, shell ratio , effective rate of rearing , absolute silk content and yield) along with common meteorological data (viz., average temperature, average relative humidity, photoperiod). The study reveals Hooghly district to be very conducive for mulberry sericulture with the multivoltine breeds to be most suitable, although rearing of F1 hybrid and bivoltine breeds should also be promoted for their better economic value. Among the seasons, late Autumn (Oct.-Nov.) and early Spring (Feb.-Mar.) are found to be most suitable commercial rearing seasons for almost all the breeds, whereas the extended summer months including Spring, Summer and rainy season (Mar.-Aug.) are unfavourable, indicating deleterious effect of temperature and humidity on the rearing performance of these breeds, for which remedies such as sub-lethal heat shock can be explored. Keywords: Silkworm rearing, cocoon weight, absolute silk content, yield, effective rate of rearing, commercial rearing season References CHANDAN, R., SANCHARI, R. M. and GHOSH, S. (2012). Sericulture as an Employment Generating Household Industry in West Bengal (A Study on its Current Problems & Prospects). Artha Beekshan : Journal of Bangiya Arthaniti Parishad., 21, 131–155. DEWANGAN, S. K. (2017). Role of women in sericulture, observation of two tribal block of Raigarh district – Chhattisgarh – India. International Journal of Emerging Technologies and Innovative Research, 4(12), 524–531. HIRASAKA, T. and KOYAMA, N. (1970). Effects of photoperiodic conditions on the larval growth of the silkworm, Bombyx mori L. II. Relationship between non-duly photoperiods and the larval growth. The Journal of Sericultural Science of Japan, 39(6), 437–442. HOQUE, A. and TAUFIQUE, M. (2018). Status and performance of sericulture in west Bengal. India: a geographical analysis. Asian profile, 46, 181–193. KUMAR, H. et al. (2013). Effect of Different Mulberry Varieties and Seasons on Growth and Economic Traits of Bivoltine Silkworm (Bombyx mori). Journal of Entomology, 10(3), 147–155. MAJUMDAR, M., SARKAR, K. and SINHA, S. (2017). A Critical Analysis on Major Problems Faced by Reelers and Weavers of Silk Industry at Field Level in Murshidabad District of West Bengal. International Journal of Social Science, 6(3), 199–210. RAHMATHULLA, V. K. (2012). Management of Climatic Factors for Successful Silkworm (Bombyx mori L.) Crop and Higher Silk Production: A Review. Psyche, 2012, 12. RAJANNA, S. P. (1986). Effect Of Photoperiod On Silkworm, Bombyx Mori Linnaeus (Lepidoptera: Bombycidae). M.SC Thesis. Bangalore: University of Agricultural Sciences. SISODIA, N. S. and GAHERWAL, S. (2017). Effects of temperature and relative humidity on commercial product of silkworm (Bombyx mori L.) in Indore region of (M.P.) India. International Journal of Zoology Studies, 2(5), 52–55. TAUFIQUE, M. and HOQUE, A. (2019). Sericulture in Malda District of West Bengal: A Block level Analysis

This research was conducted to evaluate and compare the performance of the silkworm hybrid p31×p32 reared with three varieties of mulberry leaves. In this study, the silkworms were fed with leaves from Kenmochi (Morus bombycis), native mulberry (Morus alba L.), and black mulberry (Morus nigra L.) trees and their influence on the leaf ingested, leaf digested, cocoon weight, efficiency of feed consumption to cocoon shell, efficiency of digested feed to cocoon shell weight, efficiency of digested feed to cocoon weight, and efficiency of feed consumption to cocoon weight was studied in the Torbat Heydarieh region. The results showed that silkworms that consumed leaves of Kenmochi had better performance. Also, they had better performance for traits of cocoon shell weight, feed efficiency to cocoon shell weight, and feed efficiency to cocoon weight. Therefore, Kenmochi tree is suggested for development of sericulture in the region.

Mulberry is a fast growing economically important tree for sericulture industry and contains compounds for preventing and treating several diseases and ailments. The quality and quantity of mulberry leaf available to produce silk fibre and for medicinal purpose is greatly affected by number of foliar diseases, out of which powdery mildew is the major one. Imparting genetic resistance becomes an important approach in disease management in mulberry as spraying of fungicides has harmful effects on silkworm growth and development. Deployment of non-functional susceptible genes such as Mildew resistance Locus O (MLO) against powdery mildew in few crops stimulated to identify and characterize MLO genes in mulberry. In this study, genome wide analysis identified 16 MLO genes in Morus notabilis. Phylogenetic analysis found that MnMLO2, MnMLO6A, MnMLO6B, MnMLO12A and MnMLO12B clustered with functionally characterized MLOs associated with powdery mildew susceptibility in dicot species. Gene expression analysis indicated increased transcript abundance of MnMLO2, MnMLO6A, and MnMLO12A in response to powdery mildew infection. Further, conserved motifs exclusive to functionally characterized MLOs were identified in MnMLO1C, MnMLO2 and MnMLO6A proteins. Combined analysis of the phylogenetic relationship, conserved motif analysis and gene expression in response to infection identified MnMLO2 and MnMLO6A as potential candidate genes involved in powdery mildew susceptibility in mulberry. Identification and deployment of natural and induced mutations in the candidate genes can be useful for mulberry breeding programs to develop powdery mildew resistant varieties.

The article presents the existing genetic resources of historical mulberry trees in Slovenia and reveals that pruning management and geographical distribution exhibit significant effect on certain biochemical traits. Former sericultural regions in Europe retained a number of centuries-old white mulberry (Morus alba L.) trees, which represent both, a valuable natural heritage and outstanding monuments of the very early attempts to establish a European sericulture, since their leaves were traditionally used to feed the silkworm larvae (Bombyx mori L.). The aim of the presented research was to collect data regarding eco-geographical locations of historical mulberry trees in Slovenia and to screen the content of the main metabolites in leaves to determine genotypes of local origin which are superior in individual compounds defined as feed markers. During field excursions, the highest number of mulberry trees was recorded in the Submediterranean region, followed by the Subpannonean, South-Eastern region and Central Slovenia. Pruning recordings revealed that pollarding is traditionally used in the Submediterranean region. The main phenolic compounds identified in leaves were caffeoylquinic acid derivatives, quercetin malonylhexoside, rutin, kaempferol acetylhexoside and isoquercetin. Pruning significantly affected the levels of total protein and quercetin dirhamnosylhexoside, which were higher in the annually pruned trees. Geographical distribution has a significant effect on total proteins as well as on total phenolics, caffeoylquinic acid derivatives and flavonols. Linear discriminant analysis enabled a comprehensive assessment of leaf metabolites and confirmed that mulberries of different Slovenian regions have distinctive biochemical traits. We were able to recognize caffeoylquinic acid, quercetin malonylhexoside, rutin, kaempferol acetylhexoside and isoquercetin as valuable feed markers with respect to their known beneficial effect on silkworm larvae growth and cocoon quality. By reviewing the existing mulberry genetic resources and their leaf metabolites, we highlighted the natural, cultural and scientific value of the white mulberry.

This study investigated the compost quality of sericulture waste on the growth of Anogeissus leiocarpus using two composting methods. The two-method adopted were M1 (pile method) and M2 (bin method). Sericulture waste which includes mulberry leaves and silkworm excreta were air dried for 24hours, measured (1 kg) and set in layers for both methods adopted. Samples of compost from each method were taken before planting to the laboratory for proximate analysis. Descriptive statistics and analysis of variance (ANOVA) were used to analyze the data obtained. Anogeissus leiocarpus seeds were soaked for 10 minutes at 35oC and at 9.5oC for 24 hours to enhance the breaking of its dormancy. Anogeissus leiocarpus seeds was planted using sericulture compost from both adopted methods. Result shows that M1 had the highest mineral composition. M1 recorded the highest (N %) with the value of 0.93%; (P %) with 0.089%; (K %) with 0.58%; (Ca %) with the value of 1.78% and (Mg %) with the value of 0.72% while M2 had a lower mineral composition. The result obtained for the early growth parameters shows that M1 had a higher plant height and stem girth which was significantly different from M2, the mixture of the two compost had the highest leaf count which was also significant while the control recorded the lowest value for all the parameters assessed. This result suggests that pile composting method is the best method for composting sericulture waste and can be used as a good and preferable alternative for inorganic manure in raising seedlings and trees species. Adopting the use of sericulture waste as compost will help in reducing the waste management problem, enhance economic use of farm waste and also help to ease the low germination rate and germination percentage of Anogeissus leiocarpus. Kambai, C. | Department of Forestry Technology, Federal College of Forestry, Jos, Plateau state, Nigeria

Domestic species provides a powerful model for examining genetic mechanisms in the evolution of yield traits. The domestic silkworm (Bombyx mori) is an important livestock species in sericulture. While the mechanisms controlling cocoon yield are largely unknown. Here, using B. mori and its wild relative B. mandarina as intercross parents, 100 BC1 individuals were sequenced by restriction site-associated DNA sequencing (RAD-Seq). The linkage map contained 9,632 markers was constructed. We performed high-resolution quantitative trait locus (QTL) mapping for four cocoon yield traits. A total of 11 QTLs were identified, including one yield-enhancing QTL from wild silkworm. By integrating population genomics and transcriptomic analysis with QTLs, some favourable genes were revealed, including 14 domestication-related genes and 71 differentially expressed genes (DEGs) in the fifth-instar larval silk gland transcriptome between B. mori and B. mandarina. The relationships between the expression of two important candidate genes (KWMTBOMO04917 and KWMTBOMO12906) and cocoon yield were supported by quantitative real-time PCR (qPCR). Our results provide some new insights into the molecular mechanisms of complex yield traits in silkworm. The combined method might be an efficient approach for identifying putative causal genes in domestic livestock and wild relatives.

Sericulture generates different natural products with potential medical applications. Silk peptides, worms, or even pupae are commonly employed in traditional Asian medicine with a wide variety of purposes, and some scientific work has been focused on their antidiabetic properties. This work evaluates the postprandial antihyperglycemic activity of fibroin, sericin, and powder made from either larvae or pupae of silkworms, and Bombyx mori L. (Lepidoptera: Bombycidae), employing the silkworm itself as an animal model. The results indicate a reduction in the glucose levels in hemolymph after sucrose or glucose-induced hyperglycemia when these products are included in the diet of the worms.

As a silkworm pathogen, the microsporidian N. bombycis can be transovarially transmitted from parent to offspring and seriously impedes sericulture industry development. Previous studies found that Uridine diphosphate (UDP)-glycosyltransferases (UGTs) are involved in regulating diverse cellular processes, such as detoxification, pigmentation, and odorant sensing. Our results showed that BmUGT10295 and BmUGT8453 genes were specifically induced in infected silkworms, but other BmUGTs were not. Tissue distribution analysis of the two BmUGTs showed that the transcriptions of the two BmUGTs were mainly activated in the midgut and Malpighian tubule of infected silkworms. Furthermore, there were significantly fewer microsporidia in over-expressed BmUGTs compared with the control, but there were significantly more microsporidia in RNA interference BmUGTs compared with the control. These findings indicate that the two BmUGTs were induced by N. bombycis and provided resistance to the microsporidia.

Utilization of organic formulations in pest management is a cheap, environmentally friendly alternative to chemical pesticides. This study was designed to investigate the effects of organic formulations on sucking pests damage to mulberry leaves. A field experiment was conducted with irrigated V1 mulberry variety, Department of Sericulture, Forest College and Research Institute, Mettupalayam during 2017-2018 which was laid out in Randomized Block Design with five treatments and four replications. The applications of bio foliar formulations were given thrice at 15, 30 and 45 days after pruning using knapsack sprayer and data on pest population was counted weekly for two seasons. Analysis of variance revealed significant differences between the treatment groups at 5% probability level. The results revealed that the minimum damage by different pests viz., Pseudodendrothrips mori and Aleurodicus dispersus were observed in EM and panchagavya applied plants. Thus, the foliar spray of panchagavya at 3 per cent on 15, 30 and 45 DAP is ideal for magnify the mulberry sucking pests.

This study aims to utilise sericulture biowaste, i.e. waste silkworm pupae, for mass production of the predatory stink bug Eocanthecona furcellata (Wolff). To achieve this, waste silkworm pupae wer...

Bombyx mori L., a primary producer of silk, is the main tool in the sericulture industry and provides the means of livelihood to a large number of people. Silk cocoon crop losses due to bacterial infection pose a major threat to the sericulture industry. Bombyx mori L., a silkworm of the mulberry type, has a sophisticated inherent innate immune mechanism to combat such invasive pathogens. Among all the components in this defense system, antimicrobial peptides (AMPs) are notable due to their specificity towards the invading pathogens without harming the normal host cells. Bombyx mori L. so far has had AMPs identified that belong to six different families, namely cecropin, defensin, moricin, gloverin, attacin and lebocin, which are produced by the Toll and immune deficiency (IMD) pathways. Their diverse modes of action depend on microbial pathogens and are still under investigation. This review examines the recent progress in understanding the immune defense mechanism of Bombyx mori based on AMPs.

Mulberry (Morus spp.) is regarded as a native of Himalayas and is cultivated in more than 32 countries in tropical, subtropical and temperate regions of the world. Mulberry being the sole food plant of mulberry silkworms, the quality, productivity and profitability in commercial sericulture depends on the yield of mulberry. Mulberry crop is considered as only food for the silkworm, Bombyx mori L. which is commercially exploited. It is a perennial, evergreen, luxuriant crop cultivated in all types of soils, both under rainfed and irrigated conditions. The crop is prone to depredation of diverse organisms, because of its fast growth and green foliage throughout the year, in varying proportions either for space, food or both. So far, over 300 insect and non-insect species of pests are known to infest mulberry in varying intensities during different stages of the crop and seasons. The maximum leaf yield potential of mulberry is yet to be trapped under irrigated conditions which are low for various reasons. Of these, improper nutrient management practice, decline in soil fertility status and delayed irrigation (due to failure of rains or canal water) and imbalanced nutrition and non-adaptability of prime production practices and insect pest are major constraints for low leaf productivity. Among the production constraints, sucking pest occurrence has become major problem in mulberry garden cultivation. The pests which are infesting mulberry are categorized into sap suckers, defoliators and root feeders. The sucking pest includes mealy bug, trips, spiralling whitefly, leaf hoppers, jassids and scale insects which cause damage to mulberry crop. Most of the sap sucking insects, such as adult leaf hoppers, aphids or thrips causes minimal direct tissue destruction. These insects use a specialized mouth part, the style, to locate, penetrate and drain sap from the phloem sieve elements of the plants vascular tissue. Majority of the sericulture farmers throughout the country have opined that mulberry (Morus spp.) is very much prone to sucking pest. Now a day’s majority of the mulberry cultivars and sericulture farmers have been approaching scientists and extension agencies for efficient control measures of sucking pest of mulberry especially thrips under such condition management of thrips through the eco-friendly approach and giving the crop condition in the parcel basis to the farmers is necessary to increase the mulberry leaf yield. Hence, the review.

Background Mulberry silkworm, Bombyx mori L. is one of the most economically important insect because its production of silk which interfere with many important industries. Diseases of the silkworm, B. mori such as viral, bacterial, fungal and protozoan pathogens seriously affect their cocoon production. Bacterial and fungal pathogens independently cause the highest cocoon loss, so the use of botanicals is considered an important strategy to control diseases of silkworm. Results The artificially infected silkworm, B. mori larvae with Bacillus thuriengiensis when treated with concentrations of 2 and 3% of black seed and basil leaves extracts increased significantly larval weight and decreased larval mortality. In addition, 3% basil leaves extract and 1% of black seed increased pupal weight. Cocoon weight and cocoon shell weight increased significantly by 3% basil leaves extract treatment. All tested concentrations of black seed extract increased the silk ratios of the resulted cocoons as compared to the infected control. For technological parameters, all tested extracts at 3% concentration caused the highest silk filament length; meanwhile control larvae recorded the highest silk filament weight and size. Regarding the mulberry silkworm, B. mori artificially infested with conidial solution of Beauveria bassiana when treated with all concentrations of the tested plants showed an enhancement in larval weight, pupal weight, cocoon weight, cocoon shell weight, silk filament length, and filament weight and reduced the larval mortality percentage. The highest silk filament size were recorded for the control group. Conclusions Tested concentrations of Morus alba, Ocimum basilicum leaves extracts and Nigella sativa seeds extract have suppressed the bacterial and fungal disease spread when used three times through both 4th and 5th larval instars. Moreover, the biological characters and technological traits enhanced by using of these extracts, so it can be used in sericulture for improving cocoon crop quality and quantity.

The domesticated silkworm, Bombyx mori, is an economically important insect that majorly contributes in financially viable sericulture industry. The baculovirus, Bombyx mori nuclear polyhedrosis virus (BmNPV) is a deadly virus that infects B. mori and inflicts heavy loss to silk production by causing high mortality of silkworms. A number of studies have been done to identify antiviral genes and pathways against BmNPV infection in B. mori. Toll-pathway is a well-known immune pathway responsible for combating bacterial and fungal infections in silkworm. However, the role of Toll-receptors in inhibiting BmNPV has not been explored. In the present study, we have attempted to examine the role of Toll-receptors in inhibiting BmNPV proliferation in B. mori larvae. The effect of Toll-receptors on viral proliferation was determined by quantifying viral DNA and counting viral occlusion bodies upon RNA interference-mediated knockdown of Toll-receptors in B. mori larvae. Knockdown of BmToll, BmToll-6, BmToll-7, BmToll-8 and BmToll-9 led to higher accumulation of BmNPV. Further, interplay between Toll-receptors and the antimicrobial proteins of B. mori, called seroins were studied using RNA interference. As a result, we found a downregulation of Seroin1 transcript level upon knockdown of BmToll, BmToll-7, BmToll-8, BmToll-10, BmToll-11 and BmToLK2, whereas Seroin2 expression was found to decrease only upon BmToll-7 knockdown. Moreover, knockdown of seroins did not result in clearly interpretable expression patterns of Toll-receptors. These results suggest the involvement of B. mori Toll-pathway in defense against BmNPV infection and provides a new insights into the antiviral defense mechanism of B. mori.

Microsporidia are intracellular fungal parasites and they are the most common pathogens for sericulture. Microsporidian sp. can cause pebrine, a dreadful disease and lead to destructive disorder in Muga silkworm, Antheraea assamensis Helfer by vertical and horizontal transmission. This disease is the key factor obstructing the developmental progress of Muga culture in India. Nevertheless, molecular identification and characterization of pathogen associated with pebrine disease in A. assamensis is not yet established. Insect bioassay studies revealed that microsporidian infection in Muga silkworm, A. assamensis Helfer significantly reduced (P

Production performance of silkworm (Bombyx mori L., 1758) play a pivotal role in sericulture industry and good quality cocoon represents the economic driver of farms. Silkworms are monophagus insects and differences between cocoon characteristics may depend both on mulberry tree leaves quality as well as on genetic selection of hybrid lines. While a huge work was carried out to identify the best feeding sources to optimize yields, genetic types of silkworms with desirable production and economic traits were studied to a limited extent to date. This experimental feeding trial was carried out using a commercial variety of mulberry tree leaves (Morus alba var. Ichinose) to feed a total of 1600 silkworms in 4 replicates, allotted into 32 box consisting of 50 larvae each. Feed consumption, manure production and feed conversion ratios were monitored throughout the experimental period across five instars of 8 hybrid lines (200 larvae each). Efficiency, Profitability and Eco-compatibility were identified as criteria to evaluate the best performing hybrid lines: in descending order hybrids 32 × 31, 153 × 154 and 104 × 103 have appeared the best in terms of feed conversion ratio to larva weight gain and to cocoon weight, shell to cocoon ratio and wet manure per g of dry matter intake per silkworm. Our results point to promising outcomes as to animal selection to improve yields of silk production at farm level. Sustainable and modern sericulture industry can therefore point to raise genetically selected hybrid lines of silkworms together with opportune feeding practices, to optimize feed conversions and rationalize manure in farms.

Bombyx mori nuclear polyhedrosis virus (BmNPV) is the most damaging virus for the production of silkworm cocoons. Antivirus research continues to be an important aspect of the silkworm industry. Two-dimensional electrophoresis and mass spectrometry have been applied for analyzing the midgut proteome of BmNPV-infected silkworms. In recent years, the isobaric tags for relative and absolute quantitation (iTRAQ) method has frequently been used when studying interaction between BmNPV and Bombyx mori, and useful information has been obtained. In this study, midgut proteins of BmNPV-infected silkworms were extracted from silkworm variety NIL·LVR with anti-BmNPV activity at 48 h, and proteome analysis was carried out using the label-free method. 2196 proteins were identified. Among them, there were 85 differentially expressed proteins, 45 upregulated proteins (immune-activated proteins), 28 downregulated proteins, and six proteins were specific for the BmNPV group and another six specific for control group. Many of the immune-activated proteins have been reported to have innate immune functions, and the downregulated proteins are involved in apoptosis or abnormal cell viability. In conclusion, this study provides evidence for host defense against BmNPV infection by both innate immunity and apoptosis, revealing the potential function of the midgut after oral infection of BmNPV in Bombyx mori. Significance Bombyx mori nuclear polyhedrosis virus (BmNPV) has a great impact on the sericulture industry. However, the mechanism of resistance to BmNPV has not been fully elucidated. The silkworm midgut is not only the major organ for food digestion and nutrient absorption but also an immune organ serving as the first line of defense against microbial invasion and proliferation. Here we combined label-free quantitative proteomic, bioinformatics, quantitative real-time PCR and SDS-PAGE analyses and found that BmNPV invasion causes complex protein alterations in the larval midgut of NIL·LVR with anti-BmNPV activity. The results showed that many upregulated differentially expressed proteins have been reported to have innate immune functions and the downregulation proteins are involved in apoptosis or abnormal cell viability. These findings provide evidence for host defense against BmNPV infection by both innate immunity and apoptosis, and reveals the potential function of the midgut after infection of BmNPV in Bombyx mori.

Background Sericulture depends on rearing of silkworm on mulberry leaves. For this reason, Silk production has direct relationship with larval growth. One of the alternative ways of improvement of larval growth and cocoon production is enrichment of mulberry leaves with supplementary nutrients. The present study has been aiming to find out the feed efficacy of silver nanoparticles (AgNPs) and Spirulina-treated MR2 mulberry leaves with regard to food utilization by larvae and ultimate impact on the economic parameters of silkworm (Bombyx mori). Result Fresh mulberry leaves were treated with chemically mediated AgNPs and Spirulina; it was diluted by different concentrations such as 100 ppm AgNPs (T2), 300 ppm AgNPs (T3), 500 ppm AgNPs (T4), AgNPs with Spirulina (T5), and Spirulina alone (T6). Group T1 served as the control. The result indicates significant differences among the six groups. The economic traits and the nutrient efficacy were significantly increased in AgNPs and Spirulina-treated groups when compared to those in the control. Conclusion Silkworms are the only source for producing silk. Commercial AgNPs and Spirulina administration has significantly induce food consumption, utilization, and superior cocoon characters by maintaining a balance in the gut flora. Thus, it is inferred that silkworm larvae fed with commercial AgNPs and Spirulina beneficially influence the energy and economic parameters of B. mori, which can be exploited in commercial cocoon production.

Bombyx mori nucleopolyhedrovirus (BmNPV) is one of the primary pathogens that causes severe economic losses to sericulture. Comparative transcriptomics analysis has been widely applied to explore the antiviral mechanism in resistant strains. Here, to identify genes involved in BmNPV infection, we identified differentially expressed genes (DEGs) and performed weighted gene co-expression network analysis (WGCNA) between two Bombyx mori strains: strain 871 (susceptible to BmNPV infection) and the near-isogenic strain 871C (resistant to BmNPV). Our results showed that 400 genes were associated with resistance in strain 871C, and 76 genes were related to susceptibility in strain 871. In addition, the correlation analysis of DEGs and WGCNA showed that 40 genes related to resistance were highly expressed in the resistant strain. Among them, gene BGIBMGA004291 was the most noticeable. We further identified the effect of gene BGIBMGA004291, which encoded a multiprotein bridge factor 2 (MBF2) family member (MBF2-10), on viral infection in cells. Our data suggested that MBF2-10 inhibited viral infection. Taken together, this study showed specific module trait correlations related to viral infection in strains 871 and 871C, and we identified a resistance-related gene. These findings suggested promising candidate genes with antiviral activity, aiding in the analysis of the antiviral molecular mechanisms in resistant strains.

The mulberry whitefly (Pealius mori Takashashi) is increasingly causing concern in agriculture as the distribution of this pest expands. In Egypt, the recent invasion and population expansion of the mulberry whitefly has caused particular concern in the sericulture industry. The silkworm (Bombyx mori L.), also called mulberry silkworm or Chinese silkworm, is the most important source for natural silk production. A study was conducted to examine interference by the mulberry whitefly on the population development of the silkworm. White mulberry (Morus alba L.) leaves were obtained from trees maintained in the field which had different levels of natural infestation of whiteflies (P. mori), and these were fed to silkworms in the laboratory. Regardless of instar, all silkworm caterpillars that fed and developed on white mulberry leaves that were moderately whitefly-infested (350–450 nymphs per leaf) or heavily whitefly-infested (1650–1750 nymphs per leaf) failed to molt to the next instar or failed to pupate. By comparison, 88–95% of the caterpillars that were fed non-infested mulberry leaves molted and pupated. This study demonstrates that infestation of mulberry by P. mori can have a significant negative impact on the development of silkworms. These results have high economic implications for the sericulture industry.

The blood pathogens of grasserie caused by Bombyx mori nucleopolyhedrovirus BmNPV have a serious impact on the sericulture industry. To understand the genetic status of BmNPV endemic strains in the Yunnan sericulture region, the structure and complete genome sequence of BmNPV isolated from Baoshan city of Yunnan Province were described and compared to known strains. The BmNPV-Baoshan isolate was a nucleopolyhedrovirus parasitized in silkworm larvae. Its genome has 128, 452 bp with a G + C content of 40.4%. Phylogenetic analysis clustered the virus with China BmNPV isolates; BmNPV-Baoshan was closely related to BomaNPV-S1 (both strains originated from the same ancestor). BmNPV-Baoshan strain has bro-b gene deletion, hr1 missing 4 repeat units of 30-bp palindrome structure compared to BmNPV-T3 strain. The aim of this study was to elucidate the evolution of the virus further and provide insights for the protection of virus-induced hematologic sepsis.

The mulberry silkworm, Bombyx mori (L.), is a model organism of lepidopteran insects with high economic importance. The viral diseases of the silkworm caused by Bombyx mori nucleopolyhedrovirus (BmNPV) and Bombyx mori bidensovirus (BmBDV) inflict huge economic losses and significantly impact the sericulture industry of India and other countries. To understand the distribution of Indian isolates of the BmNPV and to investigate their genetic composition, an in-depth population structure analysis was conducted using comprehensive and newly developed genomic analysis methods. The seven new Indian BmNPV isolates from Anantapur, Dehradun, Ghumarwin, Jammu, Kashmir, Mysore and Salem grouped in the BmNPV clade, and are most closely related to Autographa californica multiple nucleopolyhedrovirus and Rachiplusia ou multiple nucleopolyhedrovirus on the basis of gene sequencing and phylogenetic analyses of the partial polh, lef-8 and lef-9 gene fragments. The whole genome sequencing of three Indian BmNPV isolates from Mysore (-My), Jammu (-Ja) and Dehradun (-De) was conducted, and intra-isolate genetic variability was analyzed on the basis of variable SNP positions and the frequencies of alternative nucleotides. The results revealed that the BmNPV-De and BmNPV-Ja isolates are highly similar in their genotypic composition, whereas the population structure of BmNPV-My appeared rather pure and homogenous, with almost no or few genetic variations. The BmNPV-De and BmNPV-Ja samples further contained a significant amount of BmBDV belonging to the Bidnaviridae family. We elucidated the genotype composition within Indian BmNPV and BmBDV isolates, and the results presented have broad implications for our understanding of the genetic diversity and evolution of BmNPV and co-occurring BmBDV isolates.

A wide range of hemocyte types exist in insects but a full definition of the different subclasses is not yet established. The current knowledge of the classification of silkworm hemocytes mainly comes from morphology rather than specific markers, so our understanding of the detailed classification, hemocyte lineage and functions of silkworm hemocytes is very incomplete. Bombyx mori nucleopolyhedrovirus (BmNPV) is a representative member of the baculoviruses and a major pathogen that specifically infects silkworms (Bombyx mori) and causes serious losses in sericulture industry. Here, we performed single-cell RNA sequencing (scRNA-seq) of hemocytes in BmNPV and mock-infected larvae to comprehensively identify silkworm hemocyte subsets and determined specific molecular and cellular characteristics in each hemocyte subset before and after viral infectmadion. A total of 20 cell clusters and their potential marker genes were identified in silkworm hemocytes. All of the hemocyte clusters were infected by BmNPV at 3 days after inoculation. Interestingly, BmNPV infection can cause great changes in the distribution of hemocyte types. The cells appearing in the infection group mainly belong to prohemocytes (PR), while plasmatocytes (PL) and granulocytes (GR) are very much reduced. Furthermore, we found that BmNPV infection suppresses the RNA interference (RNAi) and immune response in the major hemocyte types. In summary, our results revealed the diversity of silkworm hemocytes and provided a rich resource of gene expression profiles for a systems-level understanding of their functions in the uninfected condition and as a response to BmNPV.

India has a prosperous and glorious history in silk production and its silk trade dates back to 15th century. Sericulture is practiced in many regions of India, where West Bengal ranks third in mulberry silk production. About 2000 villages are engaged in mulberry cultivation with plantation area of 37,883 acres. But nowadays, farmers have lack their interest in this sector due to low cost benefit ratio, high investment cost in terms of silk worm rearing, land uses and lack of proper knowledge on different races of Bombyx mori. Therefore, the present study has been aiming to find out the comparative performance of bivoltine, multivoltine, and F1 variety of B. mori by analysed the cocoon, post-cocoon characters, and silk related traits for identifying the best superior races of B. mori. The results showed that feeding habits of silkworm larvae of three races had significant effect on cocoon parameters. The average weight of ten 5th instar larvae of bivoltine was higher in comparison with multivoltine and F1 variety. Similar trends were obtained in the average length of silk thread from a single cocoon in bivoltine races, higher by 30% and 77.14% from F1 and multivoltine, respectively (PB. mori were separately clustered based on the positive correlation of measured variables mostly length of silk thread, renditta, dry cocoon weight, the average weight of larvae, present market price, leaves for rearing, net profit and selling price of cocoon per acre farmland; whereas, the multivoltine and F1 variety clustered in a separate group. From our findings, it is clear that the culture of bivoltine is preferable for the farmers who don’t have enough landed property and also profitable in terms of cocoon, post cocoon and silk traits. Therefore, it is recommended that the farming of bivoltine silkworm is more gainfulcompared to F1 and multivoltine variety, and capable of more income generation than other traditional agricultural crops.Fig.Graphical abstract represents the comparative performance of bivoltine, multivoltine and F1 races of B. mori on the aspect of biological and economic traits in tropical climate condition.

Bombyx mori, the domesticated silkworm, is an economically important insect owing to the billion-dollar sericulture industry. It is dominant amongst the other silkworm species due to its short generation time, larger progeny size and good quality of silk fibres suitable for silk production. However, B. mori is susceptible to attack by various pathogens such as bacteria, fungi, protozoa, and viruses leading to larval mortality and causing enormous economic loss to the sericulture industry. In the past decade, microRNAs (miRNAs), a group of small non-coding RNAs that function at the post-transcriptional level, have been involved in fine-tuning many biological processes, including host-pathogen interaction. Recent studies have revealed the hitherto unknown layer of host-pathogen interaction through miRNAs in many insect species. Upon infection with the virus, the insect host produces various miRNAs that manipulate gene expression of the virus, while the virus produces several miRNAs using the host small RNA machinery to surpass the host defence mechanism and successfully infect the host. This miRNA-mediated cross-talk is a subject of study to understand better the virus infection mechanism in B. mori. The present chapter highlights various B. mori as well as pathogen-encoded miRNAs involved in host-pathogen interaction. A detailed understanding of miRNAs functioning in B. mori-pathogen interactions would undoubtedly help us design effective strategies to combat pathogen attacks on the insect population.

Tropical tasar silkworm, Antheraea mylitta Drury is wild in nature and reared outdoors on its primary food plants Terminalia tomentosa, T. arjuna and Shorea robusta. The oak tasar A. pernyi silkworm is a temperate species that feeds on leaves of oak tree, Quercus sp. Tropical tasar silkworm larvae often suffer from various diseases causing heavy losses to the economy of the tasar silk industry. Virosis, pebrine, muscardine and bacteriosis are the commonly prevalent diseases caused respectively by Antheraea mylitta Cytoplasmic Polyhedrosis Virus (AmCPV, a reovirus), Nosema mylitta (Microsporidia), Penicillium citrinum and Penicillium variotii (Fungus) and different types of bacteria. In India, the extent of tasar crop loss due to the silkworm diseases is nearly 40%. The estimated crop loss due to pebrine, virosis, bacteriosis and muscardine is 20–25%, 25–30%, 10–15% and 2–5%, respectively of total crop loss. Thus, virus and bacteria cause comparatively higher levels of mortality. Seed, feed and breed are the three important parameters considered for successful sericulture. Bad weather, ineffective disinfection and poor rearing management leads to disease outbreaks and severe crop loss in tasar ecosystem. For managing these diseases, the Central Tasar Research and Training Institute (CTR&TI), Central Silk Board, Ranchi has developed various cost effective technologies such as Pebrine Visualisation Solution, Dupratex, Jeevan Sudha, Tasar Keet Oushad, etc. The details of the integrated tasar silkworm disease management is also discussed in this chapter.

Silkworm Bombyx mori, a monophagous lepidopteran insect is of great economic importance for the production of the natural fibre, silk. It is vulnerable to a diverse array of microorganisms resulting in crop losses to the farming fraternity practicing sericulture. Nosema bombycis Naegeli, a spore forming obligate intracellular microsporidia causes the devastating pebrine disease in silkworm. N. bombycis is transmitted via horizontal and vertical or transovarial transmissions. Pebrine inflicted extensive damage to the sericultural industry in Europe and Asia during the mid-nineteenth century; and still remains one of the impending challenges for the progress of sericulture across the world. The curative approaches for control of pebrine are often met with limited success and pebrine is the only disease which is being quarantined. The early detection or prevention of N. bombycis infection is an indispensable tool to control the spread of disease for stringent monitoring in the production of silkworm eggs (dfls: disease free layings; in an effect pebrine-free layings). The mother moth examination method employing light microscopy is widely used to diagnose/detect N. bombycis infection in seed multiplication farms and commercial seed production centres. Pebrine monitoring in different stages of the silkworm life cycle is of paramount importance for the sustenance of sericulture and is an integral part of silkworm disease management. This chapter summarizes the standard protocols employed for processing different samples (silkworm eggs, larvae, pupae, moth, faecal matter and dust) including sampling methods for observing pebrine spores as a part of systematic pebrine monitoring in the sericulture industry.

Insects are the largest group of animals. Nearly all organisms, including insects, have viral pathogens. An important domesticated economic insect is the silkworm moth Bombyx mori. B. mori nucleopolyhedrovirus (BmNPV) is a typical baculovirus and a primary silkworm pathogen. It causes major economic losses in sericulture. Baculoviruses are used in biological pest control and as a bioreactor. Silkworm and baculovirus comprise a well-established model of insect–virus interactions. Several recent studies have focused on this model and provided novel insights into viral infections and host defense. Here, we focus on baculovirus invasion, silkworm immune response, baculovirus evasion of host immunity, and enhancement of antiviral efficacy. We also discuss major issues remaining and future directions of research on silkworm antiviral immunity. Elucidation of the interaction between silkworm and baculovirus furnishes a theoretical basis for targeted pest control, enhanced pathogen resistance in economically important insects, and bioreactor improvement.

Background Mulberry (Morus alba L.) is an important sericulture crop; however, root-knot nematode infection seriously limits its production. Understanding the mechanism of interaction between mulberry and nematode is important for control of infection. Results Using sequencing and de novo transcriptome assembly, we identified 55,894 unigenes from root samples of resistant and susceptible mulberry cultivars at different stages after infection with the nematode Meloidogyne enterolobii; 33,987 of these were annotated in the Nr, SWISS-PROT, KEGG, and KOG databases. Gene ontology and pathway enrichment analyses of differentially expressed genes (DEGs) revealed key genes involved in hormone metabolic processes, plant hormone signal transduction, flavonoid biosynthesis, phenylpropanoid biosynthesis, and peroxisomal and photosynthetic pathways. Analysis of key trends in co-expression networks indicated that expression of unigenes 0,015,083, 0,073,272, 0,004,006, and 0,000,628 was positively correlated with resistance to M. enterolobii. Unigene 0015083 encodes tabersonine 16-O-methyltransferase (16OMT), which is involved in alkaloid biosynthesis. Unigene 0073272 encodes a transcription factor contributing to nitric oxide accumulation during plant immune responses. Unigenes 0,004,006 and 0,000,628 encode ERF and MYB transcription factors, respectively, involved in plant hormone signaling. We verified the accuracy of transcriptome sequencing results by RT-qPCR of 21 DEGs. Conclusions The results of this study increase our understanding of the resistance mechanisms and candidate genes involved in mulberry–M. enterolobii interaction. Thus, our data will contribute to the development of effective control measures against this pathogen.

Mulberry (Morus spp.) is commercially important for its foliage, as the sole feed for silkworm (Bombyx mori). The foliage quality and quantity govern the success in sericulture. Crop improvement in this tree crop through conventional and breeding approaches is slow due to the complex nature of economic traits, long juvenile period and limited understanding of existing germplasm resources. Despite the limitations in the availability of robust in vitro regeneration and transformation protocols, transgenic approach has been attempted for targeted manipulation of desired traits. To improve stress-adaptive traits and reduce post-harvest water losses from leaves, transgenic approaches have been attempted in mulberry too. This chapter highlights the need for transgenics in mulberry, and the current status of targeted trait improvement through transgenic approach is summarized.

Adverse environmental conditions cause serious economic losses in sericulture; Bombyx mori nucleopolyhedrovirus (BmNPV) is the primary biotic stress and high temperature is the major abiotic stress in this industry. B. mori heat shock protein 19.9 (Bmhsp19.9) overexpression was previously demonstrated to protect transgenic silkworm H19.9 against extreme temperature. This study analyzed the role of Bmhsp19.9 in H19.9A and H19.9B silkworm lines and BmE cells infected with BmNPV at regular and high temperatures. qPCR results showed that Bmhsp19.9 expression was upregulated in BmE cells and silkworm after BmNPV challenge. Bmhsp19.9 overexpression significantly inhibited BmNPV proliferation in BmE cells. The viral DNA content was significantly decreased in transgenic H19.9 silkworm compared to the control. These results suggested that Bmhsp19.9 was involved in antiviral immunity against BmNPV. Furthermore, Bmhsp19.9 overexpression protected BmE cells against BmNPV under high temperature shock. This indicates that Bmhsp19.9 is a promising candidate for improving silkworm resistance to biotic and abiotic stresses, thereby reducing sericulture losses.

Mulberry (Morus alba L.) is the sole food source for the mulberry silkworm, Bombyx mori and therefore important for sericulture industry. Different abiotic stress conditions like drought, salt, heat and cold stress adversely affect the productivity and quality of mulberry leaves. Quantitative real time PCR (qPCR) is a reliable and widely used method to identify abiotic stress responsive genes and molecular mechanism in different plant species. Selection of suitable reference genes is important requirement for normalizing the expression of genes through qRT-PCR study. In the present study, we have selected eight candidate reference genes in mulberry for analyzing their expression stability in different abiotic stress treatments including drought, salt, heat and cold stresses. The expression stability of these reference genes was determined using geNorm, NormFinder and RefFinder statistical algorithms. The results showed that Ubiquitin and protein phosphatase 2A regulatory subunit A (PP2A) were the most stable genes across all the treatment samples. However, analysis of individual stresses revealed different expression profiles and stability of reference genes. Actin3 and PP2A were most stable in drought and salt conditions respectively. RPL3 most preferred in heat stress and Ubiquitin was most stable in cold stress. We propose the ubiquitin and PP2A are the preferred reference genes for normalization of gene expression data from abiotic stresses. In addition, Actin3 are preferred for drought stress, PP2A for salt stress, RPL3 for heat stress and Ubiquitin for cold stress studies.

China is one of the largest producers of mulberry in the world. With the development of the sericulture industry, several pests and diseases have occurred in rapid succession, chief among which is the root-knot nematode disease affecting mulberry. According to the China cocoon and silk exchange, cocoon prices have doubled since the beginning of 2009 and rose to 92,700 yuan ($135,770) per tonne in mid-April 2010. According to customs statistics, in the first eight months of 2011, China's silk merchandise exports amounted to 2.39 billion yuan. In this study, sequencing of the rDNA-ITS and D2-D3 region of the 28S rRNA gene was combined with root-knot nematode morphological characteristics to identify the root-knot nematode infecting mulberry in the Guangdong, Guangxi, and Hunan provinces of China. This resulted in the identification of Meloidogyne enterolobii as the causal species of root-knot nematode infections in these regions. Importantly, the morphological data agreed completely with our molecular phenotyping efforts, indicating that rDNA sequencing could provide a more clear-cut and less labor-intensive means of characterizing root-knot nematode infections in the future. The differences between this study and the previous studies were discussed, as well as the damage degree, host species and influence scope of M. enterolobii. China is one of the largest producers of mulberry in the world. With the development of the sericulture industry, several pests and diseases have occurred in rapid succession, chief among which is the root-knot nematode disease affecting mulberry. According to the China cocoon and silk exchange, cocoon prices have doubled since the beginning of 2009 and rose to 92,700 yuan ($135,770) per tonne in mid-April 2010. According to customs statistics, in the first eight months of 2011, China’s silk merchandise exports amounted to 2.39 billion yuan. In this study, sequencing of the rDNA-ITS and D2-D3 region of the 28S rRNA gene was combined with root-knot nematode morphological characteristics to identify the root-knot nematode infecting mulberry in the Guangdong, Guangxi, and Hunan provinces of China. This resulted in the identification of Meloidogyne enterolobii as the causal species of root-knot nematode infections in these regions. Importantly, the morphological data agreed completely with our molecular phenotyping efforts, indicating that rDNA sequencing could provide a more clear-cut and less labor-intensive means of characterizing root-knot nematode infections in the future. The differences between this study and the previous studies were discussed, as well as the damage degree, host species and influence scope of M. enterolobii.

Improvement programs depend on characterizing genetic resources, this process being the fundamental basis for determining the diversity and genetic divergence of such resources and thereby enabling a rigorous, efficient selection of the parentals that, through hybridization, will go on to enhance heterosis. The aim was to use the resulting hybrids to improve population mean with respect to genetic parameters used for the qualitative and quantitative traits that affect commercial natural silk production. Bombyx mori L. is a domesticated insect of global economic importance, mainly due to the production of natural silk but also for its relevance in rural agro-industry in tropical and subtropical regions. Non-textile uses currently being developed are also to the fore. These relate to such fields as science and academia, biomedicine, biotechnology, the pharmacological industry and cosmetics. With this in mind, the aim of the current article was to provide a general context for sericulture and in so doing give an overview of the silk production scenario nationally and go on to describe the importance of genetic diversity to silkworm breeding programs and to demonstrate how genetic drift, inbreeding, and artificial selection contribute to loss of genetic diversity in B. mori

The silkworm Bombyx mori being a typical representative of lepidopteron insects is of great economic importance in terms of longevity having short generation time, wherein physiological, genetical, molecular and biological aspects are playing an important role. But, the mechanism of longevity has been gradually unraveled due to not realizing in-depth in basic theoretical and practical fundamentals for the several above said aspects of insects in particularly silkworm Bombyx mori. In spite of the fact, application of several biotechnological methods have been implementing in the era of advanced biology. Silkworm has to be a model organism to study the longevity, because it is an economically important insect for the silk production, wherein longevity play an important role in metabolic activities during its life cycle and understanding of its durability to reduce still shorter is the need of hour for the benefit of rearer, breeders, physiologist, biochemist, geneticist, farmers, etc in economic & scientific point of view. Regretfully, the application of theoretical and practical based theories are not possible until unless the efforts of converting into the action through proper research investigations and during various movements/programmes to reach the knowledge of longevity in a systematic way for the users. In the light of the above concept, herein this review, summarized the several important aspects are directly or indirectly influencing/effecting on longevity with providing authentically supporting evidences to understand the impact of age-related dis-orders for the standardization of life span in the insects with special reference to the Bombyx mori. The information gathered and discussed herein is a first ever effort as a review and greatly be helps to further research investigations in the field of gerontology with reference to silkworm Bombyx mori.