ABSTRACT
Host plant resistance is one of the important components for minimizing the losses because of sorghum shoot fly, Atherigona soccata (Diptera: Muscidae) attack. Therefore, we studied the constitutive and inducible biochemical mechanisms of resistance to A. soccata in a diverse array of sorghum genotypes to identify lines with diverse mechanisms of resistance to this insect. Fifteen sorghum genotypes with different levels of resistance to A. soccata were evaluated. Methanol extracts of 10-d old damaged and undamaged sorghum seedlings were subjected to high-performance liquid chromatography analysis. Association between peak areas of the identified and unidentified compounds with parameters measuring A. soccata resistance was determined through correlation analysis. Amounts of p-hydroxy benzaldehyde and the unidentified compounds at RTs 24.38 and 3.70 min were associated with susceptibility to A. soccata. Genotypes exhibiting resistance to A. soccata were placed in four groups, and the lines showing constitutive and/or induced resistance to A. soccata with different combinations of biochemical factors potentially could be used for increasing the levels of resistance to A. soccata in sorghum.
Subject(s)
Host-Parasite Interactions/genetics , Muscidae/physiology , Sorghum/parasitology , Animals , Chromatography, High Pressure Liquid , Female , Genetic Variation , Genotype , Phenols/metabolism , Seedlings/metabolism , Seedlings/parasitology , Sorghum/genetics , Sorghum/metabolismABSTRACT
Methanol, acetone and diethyl ether extracts of Alpinia galanga have been evaluated against pathogens viz. Bacillus subtilis MTCC 2391, Enterobacter aerogene, Enterobacter cloacae, Enterococcus faecalis, Escherichia coli MTCC 1563, Klebsiella pneumoniae, Pseudomonas aeruginosa MTCC 6642, Salmonella typhimurium, Staphylococcus aureus and Streptococcus epidermis using Agar well diffusion method. Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of all the extracts were determined using the macrodilution method. Methanol extracts have shown excellent activity towards all the pathogens with MIC and MBC values ranging from 0.04-1.28 mg/ml and 0.08-2.56 mg/ml, respectively. The GC-MS analysis of methanol extracts have yielded compounds like 5-hydroxymethyl furfural (59.9%), benzyl alcohol (57.6%), 1,8 cineole (15.65%), methylcinnamate (9.4%), 3-phenyl-2-butanone (8.5%) and 1,2 benzenedicarboxylic acid (8.9%), which could be responsible for its broad spectrum activity. So, A. galanga can be quite resourceful for the development of new generation drugs.
