The Development of Botanical Products with Special Reference to Seri-Ecosystem

The search for alternative ways of controlling sericultural pests has led to the investigation of plant sources for naturally occurring compounds which may have Insect growth regulatory, feeding deterrency, repellency and confusantcy characteristics. More than 2000 species of the families Asteraceae, Fabaceae and Euphorbiaceae are known that possess some insecticidal activity. Plants with insecticidal properties found in India are reported. But to use them it is necessary to conduct an analysis of the risks to the environment and to human health. Various parts of rotenone, pyrethrum, sabadilla, ryania and neem are often used to minimize pest population. Recently several other plants viz. Pongamia, Indian privet, Adathoda, Chrysanthemum, Turmeric, Onion, Garlic, Tobacco, Basili, Custard apple, Ginger and some other plants have been screened and their efficacy has been tested. The efficacy of leaf extracts of basil (Ocimum basilicum), bitter leaf (Vernonia amygdalina), lemon grass (Cymbopogen citratus), and Chenopodium ambroissoides was investigated for its insecticidal and ovicidal activity against coleopteran bruchids. Several citrus limonoids and limonin derivatives have been found to be insect antifeedants. Among all the plant originated insecticides, neem (Azadirachta indica, A. juss) is known to contain diverse array of biologically active principles of which azadirachtin (a tetranortriterpenoid) is the best known derivatives which is used in sericulture to control various pests. Botanical insecticides are prepared in the form of the crude plant material, extracts or resins. This paper includes the plants that have been reported to be insecticidal against the pests, which visit seri-ecosystem and damage the silkworm and its host plants

Genetic diversity and differentiation among populations of the Indian eri silkworm, Samia cynthia ricini, revealed by ISSR markers

Samia cynthia ricini (Lepidoptera:Saturniidae), the Indian eri silkworm, contributes significantly to the production of commercial silk and is widely distributed in the Brahmaputra river valley in North-Eastern India. Due to over exploitation coupled with rapid deforestation, most of the natural populations of S. cynthia ricini are dwindling rapidly and its preservation has become an important goal. Assessment of the genetic structure of each population is a prerequisite for a sustainable conservation program. DNA fingerprinting to detect genetic variation has been used in different insect species not only between populations, but also between individuals within a population. Since, information on the genetic basis of phenotypic variability and genetic diversity within the S. cynthia ricini populations is scanty, inter simple sequence repeat (ISSR) system was used to assess genetic diversity and differentiation among six commercially exploited S. cynthia ricini populations. Twenty ISSR primers produced 87% of inter population variability among the six populations. Genetic distance was lowest between the populations Khanapara (E5) and Mendipathar (E6) (0.0654) and highest between Dhanubhanga (E4) and Titabar (E3) (0.3811). Within population, heterozygosity was higher in Borduar (E2) (0.1093) and lowest in Titabar (E3) (0.0510). Highest gene flow (0.9035) was between E5 and E6 and the lowest (0.2172) was between E3 and E5. Regression analysis showed positive correlation between genetic distance and geographic distance among the populations. The high GST value (0.657) among the populations combined with low gene flow contributes significantly to the genetic differentiation among the S. cynthia ricini populations. Based on genetic diversity, these populations can be considered as different ecotypes and in situ conservation of them is recommended

EVALUATION OF MULBERRY GENOTYPES THROUGH BIOASSAY STUDIES

The performances of seven mulberry genotypes were evaluated to determine their suitability to silkworm rearing through bioassay studies. Experimental results revealed that leaf quality of Siss was superior to that of other varieties followed by RFS17s

Structures and magnetic behaviour of hydroxo-bridged CrIII aggregates: [Cr4(μ-OH)4(hpdta)2]2− and [Cr6(μ-OH)8(hpdta)2(en)2]

The syntheses and crystal structures of the tetra- and hexanuclear CrIII aggregates Click to view the MathML source, [Ba(OH2)5{Cr4(μ-OH)4(hpdta)2}] · 13H2O (1b) [Cr6(μ-OH)8(hpdta)2(en)2] · 10H2O (2a) and [Cr6(μ-OH)8(hpdta)2(en)2] · 14H2O (2b) (H5hpdta = 2-hydroxypropane-1,3-diaminetetraacetic acid) are reported and discussed. The antiferromagnetic interactions mediated by the bridging hydroxo ligands have been quantified. The fact that there are only a few such examples in the literature with similar bridges leads to the conclusion that a meaningful magnetostructural correlation, such as that recently proposed for oxo- and hydroxo-bridged FeIII aggregates, is not yet possible in the case of CrIII

LOW COST INCUBATION POT FOR BETTER HATCHING OF SILKWORM EGGS IN DRY SUMMER

Proper incubation of silkworm eggs play a vital role in silkworm rearing. 25°C temperature and 75-80% R.H. is ideal for incubation of silkworm eggs. The farmers do not have suitable devise for maintaining optimum temperature and humidity during incubation for obtaining uniform hatching and subsequently improvement in yield. The low cost incubation device developed is suitable for dry summer can reduce the temperature by 6-7°C and increase the humidity by 40% and thereby maintaining suitable environment for incubation of silkworm eggs. Hence, the method can be adopted at farmers' level

Genetic analysis of silkworms (<i style="">Bombyx mori)</i> through RAPD markers

389-395Mulberry silkworm, Bombyx mori L. is the most important insect being used for commercial extraction of silk in sericulture industry. To enhance the productivity and quality of silk fibers, many attempts are being made to improve the silkworm stocks through genetic manipulation. For that knowledge on the genetic diversity of the parental stocks is essential for selection and conservation of these precious materials. Keeping this in view, genetic diversity among twenty silkworm stocks differing in their yield potential and nature of voltinism was estimated through PCR amplification of the genomic DNA with 10 random amplified polymorphic DNA (RAPD) primers. A total of 68 bands were generated. Of which 61 were polymorphic (90%). The pair-wise genetic distance estimated from these bands varied from 0.058 to 0.513 with an average distance of 0.246. The cluster analysis using unweighted pair group using arithmetic average (UPGMA) grouped the silkworms into six groups and one isolate. Spatial distribution of the silkworms on two-dimensional figures using ALSCAL multidimensional scaling has broadly discriminated the multivoltine from the bivoltine silkworms. Certain silkworm stocks like Kalimpong-A, C’nichi, Nistari (P) and Mysore Princess were having higher genetic distance from others and, thus, could be used for heterosis breeding and also in breeding programs aimed at introgressing hardy genes into the bivoltine high yielding stocks

Synthesis, Structure, and Properties of New Mg(II)-Metal–Organic Framework and Its Prowess as Catalyst in the Production of 4<i>H</i>‑Pyrans

A new alkaline metal–organic framework, [Mg₃(NDC)₃(DMF)₄]·H₂O (<b>1</b>) is synthesized solvothermally by using 2,6-naphthalenedicarboxylic acid (NDC) as ligand and dimethylformamide (DMF) and water as mixed solvent. Single crystal X-ray studies show that <b>1</b> crystallizes in the space group <i>C2/c</i> with parameters <i>a</i> = 13.4191(2), <i>b</i> = 18.0669(2), <i>c</i> = 20.9746(3) Å, and β = 99.66(0)^o. The central metal atom Mg­(II) adopts a six coordinated octahedral geometry with carboxylate oxygen atoms and DMF molecules. Due to the involvement of oxygen atoms in bridging and chelation binding, a trinuclear secondary building unit is built up, which further connects to other six NDC ligands and finally leading to a three-dimensional network. The thermal and luminescent analysis revealed that the compound is thermally stable with violet emission. The creation of coordinatively unsaturated Mg­(II) centers, acting as Lewis-acidic sites upon activation, are explored to use <b>1</b> as heterogeneous catalyst in value-added organic conversions. MOF showed a superb catalytic performance in the synthesis of eight 4<i>H</i>-pyran derivatives via one-pot three-component reaction between aromatic aldehydes, malononitrile, and cyanoacetamide at room temperature. All the reactions worked exceptionally well with excellent yields (91–96%), in short reaction times (<40 min). Green solvent (ethanol) and easy separation, reusability and robust structure of catalyst are the attractions of the protocol and make [Mg₃(NDC)₃(DMF)₄]·H₂O an ideal catalyst for wide-ranging organic transformations