STUDIES ON BIOCHEMICAL CONSTITUENTS OF ROOT EXUDATES IN RELATION TO RESISTANCE FOR FUSARIUM WILT IN CHICKPEA (Cicer arietinum Linn.)
Loading...
Files
Date
2000-01-15
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
MAHATMA PHULE KRtSHI VIDYAPEETH, RAHURI-413 722, DIST,- AHMEDNAGAR
Abstract
The objective of this investigation was to identify biochemical markers involved in the resistance to Fusarium wilt in chickpea. The experiment was conducted using resistant, 'Vijay' and susceptible 'JG-62' cultivars of chickpea. The sterilized seeds of both resistant and susceptible cultivars were sown on filter paper separately for 48 hrs. The germinated seeds were kept on floating polystyrene paper in such a way that the radicals were protruding through holes in sterilized water in beaker. The root exudates obtained after 21 days were used for analysis of various biochemical constituents viz., reducing sugars, total sugars, non-reducing sugars, free amino acids, soluble proteins, trypsin inhibitor, total phenols and minerals. The differences in levels of different biochemical constituents of both susceptible and resistant cultivars of chickpea to Fusarium wilt were monitored. The reducing, non reducing and total sugars were higher in root exudate of resistant cultivar than susceptible cultivar. The reducing sugars are probably involved in the formation of the labile toxic substances, which inhibit the development by pathogen. The Abstract Contd... S. M. Patil exuded sugar might have higher concentration of galactose and lactose, which are poor source of carbon for pathogen and thus impart resistance. The higher concentration of non-reducing sugar may act as an osmoticum. Free amino acids were lower in resistant cultivar than susceptible cultivar indicating that in susceptible cultivar they may act as nitrogen source for the growth and differentiation of pathogen. The soluble protein content was higher in the root exudates of resistant cultivar. The trypsin inhibitor activity was higher in the resistant cultivar as compared to susceptible cultivar indicating that it might inactivate the proteolytic enzymes of the pathogen. The total phenolics were significantly higher in root exudate of resistant cultivar than susceptible cultivar, which probably form complex with cell wall degrading enzymes secreted by pathogen and inactivate them and protect the plant roots from injury and entry of pathogen. The minerals Viz., nitrogen, potassium, phosphorus, iron, calcium and magnesium were higher in the root exudates of resistant cultivar than the susceptible cultivar. The root exudate of resistant cultivar had a marked inhibitory effect on spore germination than that of the susceptible cultivar. The results obtained in the present investigation revealed that the root exudate, -from the resistant cultivar had higher levels of sugars, phenols, phosphorus, iron and trypsin inhibitor activity and lower levels of amino acids. These biochemicals might play important role in imparting the plant resistance to Fusarium wilt. The reducing sugars, phenols, free amino acid may be useful as biochemical markers to discriminate wilt susceptible and resistant cultivars .
Description
Keywords
null