Friesia X, 4-5

FRIESIA . Bin d X . Hefte 4-5 . 1974
PHYSIOLOGICAL STUDI ES
ON COLLETOTRICH UM TRUNCATUM
CAUSING POD BLIGHT DISEAS E IN SOYBEAN
R. K. MALHOTRA & c. CHATURVEDI
Departments of Plant Pathology & Biological Sciences ,
G. B. P ant University of Agr icultur e & Technology,
Pantnagar, N ainital , India
SUMMARY
The effect of pH and different carbon, nitrogen and sulphur
sourees on growth and sporulation of Colletotrichumi trumcat um.
(SCHW.) ANDRUS et MOORE isolated from diseased pods of soybean
was studied. Growth of the fungus was aecompained by an inerease
in pH of the medium. Optimum pH for growth and sporulation was
5.5. Suerose was the best carbon source for growth. Glueose, maltose,
laetose and suerose besides being good for growth also supported good
or exellent sporulation. Vegetative growth of the present organism
was eompletely lacking on organic acids (malie and tartarie).
Nitrates in general were eomparatively better sources than ammonium
eompounds. Glut amie acid was best nitrogen source for growth.
Nitrites were toxie. Best growth and excellent sporulation of the organism
was obtained on MgS04,7H20. ZnS04 inhibited the growth
completely. The present organism was incapable of growing in media
lacking carbon, nitrogen or sulphur.
1. INTRODUCTION
Soybean anthracnose caused by a species of Colletotr i chum was
first reported from China (HE MMI 1919). The organism involved was
named as Colletotrichum glycines HORI. Later it was found to be
similar in all respects to Colletotrichum truncat um (SCHW.) ANDRUS
Research publication under Journal Series No. 486 fr om Experiment Station.
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