Influence of nitrogen nutritions on asexual reproduction of five species Sphaeropsis sacc. in culture

Effect of fourteen different nitrogen sources on five species ofSphaeropsis i. e.S. cactinae, S. cycadis, S. jodhpurensis, S. muehlenbeckiae andS. punicae, obtained respectively from the infected parts ofCitrus medica, Cycas circinalis, Cordia gharaf, Muehlenbeckia platycladoes andPunica granatum was studied, under cultural conditions on Asthana and Hawker's Medium A by substituting its nitrogen with equal quantity of an other nitrogen source. All the present species reproduced well on potassium nitrate, sodium nitrate, ammonium sulphate and ammonium nitrate. None of the present species could grow on sodium nitrite. Out of all amino acids, no one was found to be excellent for the growth and sporulation of the present fungi. Most of the amino acids supported poor growth and sporulation of three of the five species ofSphaeropsis, S. cactinae, S. cycadis andS. punicae on L-asparagine, Glycine, L-cystine and L-alanine. Maximum and minimum pH for growth and sporulation ranged from 6.5 to 7.8 and 5.3 to 4.2 respectively. Decrease in adjusted pH was also observed for all the species on L-asparagine and DL-valine.