Cylindrospermum sp. NDOP002 was isolated from agricultural fields of Azamgarh, U.P., India. It was characterized by morphological methods. Total chlorophyll a content was 18.5 µg/ mg dry weight. Organism achieved a stationary phase of growth after 15 days of cultivation. Ammonia excretion was monitored from 6 hrs. of culture to 20 days. The ammonia content of culture increased up to 7 days (Maximum amount of 3.23 µg/ ml) and then decreased. Approximately a constant amount of ammonia was maintained from 9th and onwards days of growth. Maximum glutamine synthetase (GS) activity of 8.33 mM ?glutamyl hydroxamate min-1 mg chl-1 was observed on the 5th day of culture and then decreased. Approximately constant GS activity was observed after 9th and onward days of growth. Algalisation experiment showed an increase in growth parameter of rice plant in algalised set. Length of roots was 6.4-6.9 cm in non algalised and 7.2-7.6 cm in algalised rice plants whereas the length of shoots was 5.7-6.1 cm in non- algalised and 9.5-10.1 cm in algalised rice plants. The amount of ammonia in algalised set was 2.1 µg/ ml on the 10th day of the experiment. Experimental findings clearly suggest Cylindrospermum sp. NDOP002 as suitable inocula for algalisation of rice fields of Azamgarh district, U.P., India.
Isolation and characterization of a factor from Bipolaris zeicola race 3 that induces susceptibility in rice plants.
