RESUMEN

The domesticated silkworm, Bombyx mori serves as an ideal representative of lepidopteran species for a variety of scientific studies. As a result, databases have been created to organize information pertaining to the silkworm genome that is subject to constant updating. Of these, four main databases are important for store nucleotide information in the form of genomic data, ESTs and microsatelites. These databases also store data related to other lepidoptera and important insects, which help in insect biological research. Though a considerable amount of nucleotide data is currently available, there is a paucity of data related to silkworm and other lepidopteran proteins. Hence, the focus of this article is to present the current status of nucleotide databases of silkworm, avenues for improvement and possibilities for databases that could be created in the future.

RESUMEN

Effects of sinusoidal magnetic fields on chawki silkworm rearing have been studied. The experiment was conducted using a multi X Bi silkworm hybrid, PM x CSR 2. Disease-free layings were reared from hatching to cocooning and by subjecting first and second instar to three magnetic field frequencies: 0.1, 1.0, and 10 Hz at 1500 nT, pp, for six days at six hours per day. Controls were maintained simultaneously. Larval durations for both young-stage chawki (I and II) and late stage (III, IV, V) were calculated in days and hours, including the feeding and moulting periods for I to IV instars, and the feeding period for V instar up to the time of spinning. The study revealed that the magnetic exposures reduced both feeding and moulting times with no adverse effects on larval growth. The substantial reductions in time, 33 hours in instars I and II, and 64 hours in total larval duration, could be commercially important in chawki rearing, saving time, leaf consumption, and labor expenses.

Asunto(s)

Bombyx/crecimiento & desarrollo , Bombyx/efectos de la radiación , Conducta Alimentaria/efectos de la radiación , Muda/efectos de la radiación , Agricultura/métodos , Animales , Campos Electromagnéticos , Conducta Alimentaria/fisiología , Larva/crecimiento & desarrollo , Larva/efectos de la radiación , Muda/fisiología , Dosis de Radiación , Textiles , Irradiación Corporal Total

RESUMEN

A high frequency of tetraploidy was induced in mulberry (Morus alba L.) through apical bud treatment under in vitro conditions. Apical buds from in vitro-grown plants were treated with three different concentrations (0.05, 0.1 and 0.2%) of colchicine in MS medium for 24 h. Tetraploidy at a frequency of 39.4±4.8% was obtained using 0.1% colchicine, whereas the frequency of tetraploidy was significantly reduced to 16.7±2.3% when 0.2% colchicine was used. Morphological, histological and cytological evidence indicated a phenotypic and genomic similarity of in vitro- with ex vitro-induced tetraploids. Rooting of tetraploids was on basal medium containing 2.6 µM NAA. The recovery of tetraploids was 80.8% more efficient using the in vitro method instead of the ex vitro method. The use of the same colchicine medium for up to 4 weeks with additional explants was found to be equally effective for the induction of tetraploidy.