Arfaoui, A. and Sifi, B. and Boudabous, A. and El Hadrami, I. and Chérif, M.
(2006)
Identification of rhizobium isolates possessing antagonistic
activity against fusarium oxysporum f.sp. Ciceris,
the causal agent of fusarium wilt of chickpea.
Journal of Plant Pathology , 88 (1).
pp. 67-75.
![[img]](http://eprints.icrisat.ac.in/style/images/fileicons/application_pdf.png) |
PDF
|
Abstract
Using two cultivars (the susceptible ILC482 and the
moderately resistant INRAT 87/1) of chickpea (Cicer
arietinum), the antagonistic activities of 21 Rhizobium
isolates were tested in vitro in dual culture, and in vivo
under greenhouse and field conditions against Fusarium
oxysporum f.sp. ciceris (Foc) race 0, the causal agent of
Fusarium wilt of chickpea. In dual culture, 14 isolates
inhibited the mycelial growth of the pathogen more
than 30% and the most effective were Rh8, Rh11, Rh16
and PchSOM, which inhibited fungal growth more than
50%. Among the 14 Rhizobium isolates tested for
volatiles, cyanide production and phosphate solubilisation,
8 significantly inhibited fungal growth by producing
volatiles, 6 were positive for cyanide production and
only three were able to solubilise phosphate. Isolate Rh8
produced the highest levels of volatiles, giving more
than 10.7% fungal inhibition, and was the only one positive
for both cyanide production and phosphate solubilisation.
Greenhouse experiments on the same 14 isolates
revealed the effectiveness of five: PchDMS, Pch
121, Rh5, Rh17 and Pch43. These reduced the percentage
of wilted plants in both susceptible and moderately
resistant cultivars. These percentages ranged from 12.5
to 54.6% in the susceptible cultivar ILC482 and from
8.3 to 29.1% in the moderately resistant cultivar INRAT
87/1. The best disease control was achieved by isolate
PchDMS. Despite its effectiveness in vitro, isolate Rh8
was ineffective under greenhouse conditions. Field experiments
showed that none of the 14 Rhizobium isolates
significantly reduced the percentage of wilted
plants of the susceptible cultivar ILC482, although with
the moderately resistant cultivar INRAT 87/1 eight of
the isolates significantly reduced wilt incidence. Inoculation
of seeds with these isolates reduced the percentage
of diseased plants from more than 48.6% in infected
control plants to less than 20.3% in plants inoculated
with the bacteria and infected with the pathogen.The best protection against disease was obtained with
isolates Pch43 and Rh4, which reduced the percentage
of wilted plants to less than 8%. Besides their beneficial
effects on disease control, our studies showed that rhizobia
may improve plant growth and yield. These results
indicate that Rhizobium isolates could be effective
under commercial conditions in reducing the deleterious
effects of Fusarium wilt
Actions (login required)
 |
View Item |
