Download - OAR@ICRISAT

131
Pathology
abundance at only the lowest levels
(0.002 - 0.004%).
PRASAD, M., and S.K. CHAUDHARY. 1967.
Effect of sulfur on sporulatlon of Fusarium
udum B u t l . J. Indian Bot. Soc. 46(1):
45-51. 1042
The s u l f u r n u t r i t i o n of Fusarium udum
Butler was studied. Ten concentrations of
s u l f u r , supplied as MgSO 4 7H 2 O were t r i e d
for t h e i r effects on mycelial growth,
conidial production, and chlamydospore
formation. While 0.32% of S was optimum
f o r growth and conidial production,
chlamydospore formation was best at 0.008%
and 0.016%. Beyond the optimum, growth
as w e l l as sporulatlon declined sharply.
PRASAD, M., and S.K. CHAUDHARY. 1977.
Relation of pH levels and varied n u t r i e n t
media to growth and sporulatlon of Fusarium
oxysporum f. udum (Butler) Sn. et H. Res.
J. Ranchi Univ. 13:214-222. 1043
In Fusarium oxysporum f . udum best mycelial
growth and sporulatlon of macroconidia and
microconidia were recorded at pH l e v e l of
6.0; chlamydospores, however, sporulated
best at pH 3.5 and least at pH 6.0. For
macroconldlal and microconldlal sporulatlon
as w e l l as for mycelial accumulation, the
pH l e v e l of 6.5 had a positive adverse
e f f e c t . With the age of c u l t u r e , the
comparative performance of the d i f f e r e n t
media v a r i e d . The best growth was in
Rawlin's and Richard's media, the sporulat
l o n of macro and microconidia were best
in potato-dextrose and Cpapeck's media
respectively.
PRASAD, S.N. 1965.
Studies on s t e r i l i t y disease of 'rahar'
(Cajanus cajan). Allahabad Fmr 39(6):
235-237. 1044
Symptoms of the mosaic v i r u s disease on
small and chlorotic leaves and suppression
of flowering are l i s t e d . F i r s t symptoms
in l a t e v a r i e t i e s appeared 10th day a f t e r
the date of f i r s t flowering. A l l v a r i e t i e s
were more or less susceptible to the
disease. At harvesting time the infected
plants were 10 to 35% and 100% in semi-late
v a r i e t i e s . Severely diseased branches did
not form flower buds.
PRESTON, N.W. 1977.
Cajanone: an antifungal isoflavanone from
Cajanus cajan. Phytochem. 16(1):
143-144. 1045
Description of molecular structure of
Cajanone is given. Cajanone, isolated by
TLC from a methanolic extract of d i r e c t ,
milled pigeonpea r o o t s , t o t a l l y i n h i b i t e d
germ tube growth of Fusarium oxysporum f.
sp. udum, the pigeonpea w i l t pathogen, at
50 ppm in vitro.
PURKAYASTHA, R.P., and ARATI DAS. 1973.
Amino acids associated with pathogenicity
of UV-induced mutants of Fusarium udum.
i n c i t i n g w i l t of pigeonpea. Proc. Indian
Sci. Cong. Assoc. 60(3):357.
(Abstract). 1046
A v i r u l e n t s t r a i n (FU 13) of F. udum was
subjected to UV-radiation. The 0.01% surv
i v a l was most useful in producing the
highest rate of mutation. Of the 400 surv
i v i n g colonies studied, 8 stable amino
acid-deficient mutants were isolated and
characterized. Four of these mutants
required methionine either singly or a l t e r ­
natively while one mutant (M60 2 ) had three
alternate deficiencies as methionine/
c y s t e i n e / c i s t l n e . Growth responses of
M60 2 and a methionine-requiring mutant
(M60 7 ) were studied in vitro. The pathog
e n i c i t i e s of M60 2 and M60 7 were tested on
a susceptible v a r i e t y of Cajanus cajan.
It was observed that inocula, supplemented
with optimal concentrations of the required
amino acids p a r t i a l l y restored the pathogenicity
of the test mutants which were
otherwise nonpathogenic. Methionine,
however, appeared to have an important
role in pathogenesis.
PURKAYASTHA, R.P., and M. CHATTOPADHYAY.
1975.
A n t i b i o t i c s e n s i t i v i t y of normal and amino
a c i d - d e f i c i e n t mutants of Fusarium udum
in r e l a t i o n to control of w i l t disease of
Cajanus cajan (L.) M i l l s p . Indian J.
Expl B i o l . 13(1):58-60. 1047
S e n s i t i v i t y of three UV-induced amino a c i d -
d e f i c i e n t mutants in F. udum and t h e i r
parent s t r a i n (FU 13) to four a n t i b i o t i c s
was tested in vitro, Aureofungin (100 µg/
ml) most e f f e c t i v e l y i n h i b i t e d spore germination,
germ tube, and mycelial growth
of the test s t r a i n s . Pathogenicity tests
on C. cajan revealed that FU-13 and M-802
were v i r u l e n t and avirulent respectively,
while M-602 and M-607 were nonpathogenic.
Selective t o x i c i t y of a n t i b i o t i c s to test
strains was discussed in r e l a t i o n to the
control of w i l t disease of C. cajan.