The biochemical changes in mustard leaves and seed due to alternaria blight infection

To find out the biochemical changes (total phenols, O-dihydroxy phenols, soluble protein, Chlorophyll content, total sugar and reducing sugar) in leaves and seed under different degree of severity. The leaves of different time treatments of Mancozeb @ 0.2% with different severity was collected and analyzed. Protein, total sugar, chlorophyll content and reducing sugar showed (−0.984, -0.983, -0.998, and -0.980) correlation coefficient with PDI, respectively. These values clearly indicate that the protein, total sugar, chlorophyll, and reducing sugar contents of leaf gradually and significantly decreased with the increase in PDI. In contrast to this disease intensity showed a highly significant and positive correlation with total phenol (r = 0.975**) and O-dihydroxy phenol (r = 0.794**). This indicates a significant increase in total phenol and O-dihydroxy phenol with the increase in Alternaria blight of mustard. Alternaria pod blight showed a highly significant and negative correlation with the total Protein content (−0.919**) and reducing sugar (−0.971**). This indicates that the total protein content of seed and reducing sugar gradually decreases with the increase in the intensity of Alternaria pod blight.The disease has also showen a highly significant negative correlation with the thousand seed weight (−0.880**) and seed dicolouration (−0.910**). which indicate that the thousand seed weight gradually decreases with the increase in Alternaria pod blight.Similar to seed weight the seed discolouration also gradually increase with the increase in the pod blight itensity. A highly significant and positive correaltion coefficient was obtained in between PDI and seed texture (r = 0.862**). This highly significant and positive correlation reveals that the wrinkling on seed surface increases with the gradual increase in intensity of Alternaria pod blight.