Shrimps survive white spot syndrome virus challenge following treatment with Vibrio bacterin.

Taking an innovative approach, a vaccination study using five bacterial strains viz. Vibrio campbelli (B60), V. alginolyticus (B73), V. parahaemolyticus-like (B79), V. parahaemolyticus (R8) and V. harveyi (RG203) was conducted in Penaeus monodon against white spot syndrome virus (WSSV) infection, considered as one of the serious pathogens of shrimps. Oral challenge with shrimps infected with WSSV showed a relative percentage survival of 5 and 47% in the P. monodon juveniles vaccinated with V. parahaemolyticus and V. harveyi, respectively. Results showed that there is a possibility of specifically immunising the shrimps against WSSV using bacterin prepared out of Vibrio harveyi isolates taken from shrimps infected with WSSV. Also, there was a level of protection attained by the shrimps due to immunisation with Vibrio strains.

Biochemical studies of embryogenic and non-embryogenic callus of Cardiospermum halicacabum L.

Some physiological and biochemical changes were measured between embryogenic and non-embryogenic callus obtained from Cardiospermum halicacabum. Combination of auxin with cytokinin was more favourable for high amount of callus formation. 2,4-D played a key role in triggering somatic embryo formation. Embryogenic callus had more total carbohydrate and starch contents, total free amino acids, nucleic acids, phenols and ascorbic acid. Non-embryogenic callus exhibited high chlorophyll content, total soluble sugar, protein, ammonia and enzymes like peroxidase and polyphenol oxidase. Thus, the present study indicated that the process of somatic embryogenesis was characterized by some biochemical and physiological changes induced by plant growth regulators.