Biological characteristics ofSalmonella weltevreden typing phages

The important biological characteristics ofSalmonella weltevreden (3,10∶r∶z₆) typing phages were studied. On the basis of these, the phages could be classified into three groups: phages Φ I and Φ II, phages Φ III, Φ IV and Φ VI, and phage Φ V. Part of the work was done at the National Salmonella and Escherichia Centre, Central Research Institute, Kasauli, India.     

Factors affecting in vitro formation of cormlets in <Emphasis Type="Italic">Gladiolus hybridus</Emphasis> Hort. and their field performance

The effect of number of important factors on in vitro cormlet formation has been investigated in Gladiolus hybridus Hort. Sucrose concentration of 232 mM was found to be best for producing higher number of cormlets per flask, whereas, the average mass of a cormlet increased with increase in sucrose concentration. Amongst three cultivars (cvs), maximum number of cormlets produced per flask was recorded in cv ‘Her Majesty’, but the average cormlet mass was higher in case of cv ‘Bright Eye’. Although the number of cormlets produced was found to be marginally higher at 30°C when compared with 20°C, the average cormlet mass was higher at the lower temperature. Both the number of cormlets formed per culture flask as well as the average fresh mass of a cormlet increased with increase in the size (volume) of the culture flask used. The known inhibitors of gibberellin biosynthesis used in this study suppressed cormlet formation, and the maximum inhibition was recorded in case of maleic acid hydrazide. Polyamines were found to be beneficial for cormlet formation, and amongst the polyamines used, incorporation of spermidine in the culture medium resulted in maximum number of cormlet formation per culture flask. Field trials indicated that the performance of such in vitro produced cormlets was comparable to that of conventionally produced cormels of the same weight range. The plants raised from in vitro produced cormlets were found to be morphologically similar to the mother plant.