MLN Breeding Line Scoring Scale

  1. Breeding Line Scale
SCORE SYMPTOMS DESCRIPTION
1 Clean. No visible symptoms
 2    Fine chlorotic specks, but vigorous plants
 3    Mild chlorotic streaks on emerging leaves
 4   Moderate chlorotic streaks on emerging new leaves  
 5    Chlorotic streaks and mottling throughout plant
 6   Intense chlorotic mottling throughout plant, necrosis of leaf margin  
 7    Excessive chlorotic mottling, mosaic and leaf necrosis. At times dead heart symptoms.
 8    Excessive chlorotic mottling, leaf necrosis, dead heart and premature death of plants.
 9    Complete plant necrosis, and dead plant.