Effect of Bemisia Tabasco (Whitefly) on Photosynthetic capacity and secondary metabolite composition of selected cassava varieties grown in Uganda

Abstract

Cassava is the largest source of functional food and nutrition in many countries. It is considered a staple food in many countries as well a cash crop as a source of income for farmers who play a role in improving their own welfare. This study was focused on understanding the effect of the whitefly on the photosynthetic machinery which would later aid in accessing the performance of both tolerant and susceptible varieties through additional study of production of secondary metabolites. This knowledge will be used by breeders to effectively perform a breeding program to obtain improved cultivars. Four varieties NASE 3, NASE 13, NASE 14, and Mkumba were used in this study and samples analyzed at 6months from planting. Samples taken showed variation in the chlorophyll contents (p<0.05) with NASE 13 having a significantly higher chlorophyll content retained after infestation compared to other varieties. Cynogenic potential was too measured across all the varieties and there was a strong significant difference (p<0.01) between the varieties with NASE 13 have the least significant levels which I considered a better adaptation than Mkumba which had the highest significance of 0.59ppm. The less significant levels proved the palatability of infested plants even when mixed with the controls or the non infested. However, NASE 13 was highly significant with production of other phenolic acid derivatives as these were the responses to whitefly infestation which placed it as a better variety compared to the others. This study, therefore presents comprehensive evaluation of selected varieties and attained results that show NASE 13 as a better variety from which to breed for tolerance and resistance against the whitefly.