Document Type : Original Article
Authors
1
Zoology and Agriculture Nematology Department, Fac. Agric., Cairo University
2
Nematology Unit., Plant Protection Department, Desert Research Center, Cairo
Abstract
The potency of the some chemicals from different groups known as inducers
of systemic acquired resistance (SAR) viz., acetylsalicylic acid (ASA), DL-3-
aminobutyric acid (BABA), 2,6-dichloroisonicotinic acid (INA), 5-chlorosalicylic acid
(CSA), nitrosalicylic acid (NSA),salicylic acid (SA),ascorbic acid (AS), and selenium
(SE) in reducing reproduction Meloidogyne incognita in tomato plants cv. Castel
rock was investigated under greenhouse conditions. Supplying chemicals three
days-before nematode inoculation showed maximum efficacy in reducing nematode
galls, egg-masses and eggs numbers followed by synchronized addition with
inoculation, while post-inoculation treatment was less effective. Reiterative doses
post-inoculation were improved the efficacy of single dose, also three doses used
were more effective than one or two, while, differences between two or three doses
were insignificant. On the other hand, plant fitness was slightly impaired with third
dose than second one. INA and SE showed pronounced effect in inhibition
nematode population after third dose compared with the rest chemicals, which
showed mild increase in their efficacy from second to third doses. Unfortunately,
three doses of SE were reduced plant fitness after enhanced by double doses,
while INA was showed obvious phytotoxicity gradually increased by repeating
doses. Gathering between the most effective application time (before inoculation)
and the proper activated dose after inoculation was studies for emphasized their
action and comparing with pre-inoculation only in suppressing M. incognita
population. Chemical activators showed enhancing in peroxidase and
polyphenoloxidase activities. In conclusion, CSA, NSA, BABA and SA were showed
highest efficacy as resistance inducers. This collectively showed reduction of total
population with pre-inoculation time application and pre plus post-inoculation
application, 57.6&83.8%, 56.5&81.6%, 55.4&79.2% and 54.5&78.1%, respectively.
Also the fecundity of nematode was taking similar trend as total population. The
results suggest that tested chemicals especially CSA, NSA, BABA and SA have
potential to suppress root-knot nematode infection in tomato plants through induced
systemic resistance.
Keywords
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