High performance liquid chromatography for the detection and estimation of amino acids in relation to Fusarium wilt (panama disease) in banana

Panama disease of banana is an obnoxious disease caused by the fungal pathogen Fusarium oxysporum. The variation in the degree of susceptibility and resistivity depends upon several macronutrients, micronutrients, polyphenols and primary metabolites-carbohydrates, protein and lipids and free amino acids in the host. Studies on such relationships between free amino acids and host-pathogen interaction are limited in agricultural crops particularly on materials based on the traditionally cultivated land are scarce. In order to understand the role of free amino acids of the host-banana in relation to Fusarium-wilt disease, HPLC study was carried out in five susceptible (Healthy/Infected) and five resistant varieties of banana from Tirunvelveli district. The results show the quantitative difference in amino acids of susceptible-healthy, susceptible-infected and resistant varieties. Inter-varietal difference in quantity of various amino acids in each group of samples has also been observed. Except two amino acids, tyrosine and lysine, all the other 13 amino acids are present in maximum amount in the infected samples of Monthan and Nadu in which the healthy samples are with very low amount of amino acids. Lysine and tyrosine are present in maximum amount in healthy samples of Rasthali and Rasakathali respectively. Major change in the quantity of arginine is related with the production of Nitric Oxide, an important chemical related to disease resistance. Occurrence of enormous quantity of glutamic acid, an important cellular osmolyte, in infected sample has been attributed to the role in controlling water loss by controlling the stomatal movement and thus ultimately save the infected plant from wilting

Spectroscopical differences among soil samples of selected susceptible and resistant varieties of banana in relation to wilt disease

Banana is an important cash crop cultivated in several states of India, including Tamil Nadu. Wilt disease caused by the fungal pathogen is a severe disease of banana resulting in great economic loss to the farmers. Although the pathogen occurs in the soil and in suckers, the visible symptoms may be seen only after several months. In the meantime, for the development of disease, the physico-chemical factors of the soil along with the atmospheric factors play an important role. So it is an important step to maintain the unfavourable soil condition for the pathogen by analysing the soil samples. In the present study, spectroscopical analysis has been done in order to know the difference between the soil of healthy and diseased plants of five susceptible varieties and five resistant varieties of banana from various localities of Tirunelveli district, Tamil Nadu. The results of macronutrients (NPK) obtained by classical quantitative methods, have been confirmed by IR spectroscopic analysis.  Thus the IR spectroscopic analysis of soil samples clearly shows the difference in absorption spectrum between soil samples of susceptible (diseased and healthy) and resistant varieties of banana. Such spectroscopic difference is mainly due to the difference in concentration of macronutrients (NPK). Thus it is concluded that, when compared to tedious-classical methods of soil analysis, the simple and quick spectroscopic analysis of the soil will be more useful to identify the soil which is more conducive for the development of wilt disease in Banana