The reaction of Amaranthus hybridus to infection by Amaranthus mosaic virus

Abstract

This study investigated the effect of inoculating three Amaranthus hybridus cultivars: NHAM/114, NH84/457-IL and LOCAL GREEN cultivar with Amaranthus mosaic virus (AMV) consecutively for four weeks. Results indicated significant differences between the control and virus inoculated plants. Severity of infection by the virus was more pronounced in plants inoculated at early ages while the effect was very mild on plants inoculated at later stage of growth. Reduced weight values were recorded in plants with early infection compared to plants inoculated at later stages of growth. Mean values of 0.190, 0.250 and 0.218 g were obtained for fresh weights of leaves of NHAM/114, NH84/457-IL and LOCAL GREEN respectively at 2 weeks after planting (WAP) while plants that were inoculated at 5 WAP had average values of 0.516, 0.392 and 0.397 g fresh weights of leaves for the three cultivars respectively. The percentage decrease in fresh weight of stem of the LOCAL GREEN cultivar was above average (56%) and higher than those of NHAM/114 and NH84/457- IL. NHAM/114 produced the least dry weights in stem while the highest dry weights were recorded for NH84/457-IL at all the stages of inoculations. These results indicated that infection at an early age resulted in greater reduction of the parameters assessed.