Abstract Book - 3rd International Symposium on Medicinal Plants ...

The 3 RD <strong>International</strong> <strong>Symposium</strong> on Medicinal Plants, their Cultivation and Aspects of Uses
Topic (5): The Use of Extracts from Medicinal Plants as Part of Integrated Pest
Management Programs
5.1 Biological Control of Leaf Spot Disease by A Few South Indian Medicinal
Ferns
A. John De Britto
PG & Research Department of Botany, St.Xavier’s College (Autonomous) Palayamkottai – 627
002 Tamil Nadu India
<strong>Abstract</strong>: Leaf spot is a common disease in agriculture with severe yield loss. This harmful
disease is caused by a phyto pathogenic bacteria namely Xanthomonas campestris. It is a multiantibiotic
resistant bacterium. Many vegetable and cash crops are severely affected by the leaf
spot disease which is caused by X. campestris. These bacteria have acquired resistance to
synthetic pesticides. Pathovars of Xanthomonas are reported to have developed resistance to
kanamycin, ampicillin, penicillin and streptomycin. Considering the resistant potency of X.
campestris, there is an urgent need for alternative agents for the management of this pathogenic
microorganism. Pteridophytes (ferns) are one of the oldest land plant groups on earth and
constitute a vast group of vascular cryptograms. Ferns also show medicinal utility and many of
them are being used medicinally from ancient time. These plants are resistant to a wide array of
pathogens. The rich diversity of Indian medicinal ferns has been evaluated for their antimicrobial
properties, and this may have proved beneficial for mankind. All the parts like rhizome, stem,
fronds, pinnae and spores contain antimicrobial and medicinal potency due to the presence of
secondary metobolites. Hence in the present study biocontrol activity of ten south Indian medicinal
ferns on X. campestris was investigated. The antibacterial activity of five solvent extracts of ten
medicinal ferns collected from the Western Ghats of south India was checked by agar disc
diffusion method on MH agar medium. The methanol extracts of all the ferns gave successful
result against the tested bacteria. Phytochemical analysis of all the extracts revealed that
antibacterial activity is due to the presence of alkaloids, flavonoids and phenolic compounds.
According to the results of MIC (Minimum Inhibitory Concentration) and RPI (Relative Percentage
Inhibition) values, ferns extracts could be used as bio control agents for the management of
pathogenic bacteria X. campestris.
Key words: Antibacterial activity, leaf spot, pteridophytes, Xanthomonas campestris.
5.2 Activity of Neem (Azadirachta indica a.juss) Extracted (Azadirachtin) on
Mosquito Culex Pipiens pipiens (Dptera: Culicidea)
ALOUANI, Abdelouaheb 1 REHIMI, N and SOLTANI, N 2
1 Department of Biological Sciences, University of Ibn Khaldoun –Tiaret. 2 Department of Biological
Sciences, University of Badji Moukhtar Annaba, Algeria.
<strong>Abstract</strong>: Various neem products have been researched extensively for their phytochemistry
and exploitation in pest control programmes. A number of bioactive components have been
Isolated from various parts of the neem tree (Azadirachta indica ; Meliacae).These chemical
compounds have different designations, among which Azadirachtin is the major component, and
the predominant insecticidally active ingredient of seed, leaves, and other parts of the neem tree.
Neem components show multiple effects against different insects such as mosquitoes.
Azadirachtin (3.2% w/w) was tested for its effects against 1 th and 2 nd instars larvae of Culex pipiens
(Diptera: Culicidae) under laboratory conditions, following the standard World Health Organization
insecticide susceptibility methodology. The results have been exploited according to classic
statistical methods. A linear correlation was revealed between concentration and larval mortality .
At first stage, larval mortality increased from 44.44 % at 0.125 mg /L to 93.05 % at concentration
1mg /L of azadirachtin in direct effect. The median lethal concentration (LC 50 ) values was 0, 18
mg / L. Cumulate mortality increased from 54.28% to 95.71% at 0,125mg/L and 1mg/L
respectively. The LC50 value for the indirect effect was 0.12 mg/L. At second stage, larval
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