In vitro culture, transformation and genetic fidelity of Milk Thistle.

This review article presents a consolidated explanation and provides a comprehensive description of various studies, carried out on in vitro culture and hairy root cultures of S. marianum which can be consider an alternative source of flavonolignans. To overcome the constrains of conventional propagation of silybum plant, tissue culture and advanced biotechnology proved to be an influential tool that can complement conventional breeding and accelerate silybum development. The present review is focused on biotechnological tools like in vitro culture, hairy root cultures and genetic fidelity of S. marianum which can be a potent tool for production of secondary metabolites from these cultures.

Diversity of Bacillus thuringiensis isolates from Egyptian soils as shown by molecular characterization.

Different techniques were adopted for molecular characterization of several indigenous strains of Bacillus thuringiensis (Bt) previously isolated from Egyptian soil samples. These isolates show different toxicity levels against neonate larvae of both insect species; Spodoptera littoralis (Biosduval); and Helicoverpa armigera (Hübner). The parasporal crystals among the most potent isolates contained polypeptides of about 127 and 130 kDa. PCR screening for genes encoding different Cry genes was performed. The Cry 1 gene is the most abundant in these isolates (83.33%) among tested Cry-type genes, followed by Cry 1 gene subfamilies (Cry 1B and Cry 1C) with percentage of 38.88% and 77.77%, respectively. The tested isolates showed the presence of Cry 2A(a,b) gene, but not all of these isolates were positive for Cry 2 gene (55.55%). Only 27.77% and 16.66% of the tested isolates harbor Cry 4 and Cry 3 genes, respectively. All strains were negative in PCR assays for the Vip 3Aa1 gene. Moreover, DNA fingerprinting using RAPD-PCR was performed to detect the genetic similarities and dissimilarities among the different isolates and standard strains. Assessment of Bt diversity based on the combined analysis of their protein and RAPD-PCR banding patterns was performed. This study demonstrates that Bt strains isolated from Egyptian soil samples can be distinguished and identified on the basis of the distribution of Cry-type genes and RAPD fingerprints.