Figure 1
Symptoms
Fruit
The primary symptom of Raspberry bushy dwarf virus (RBDV) in both red and black raspberry is crumbly fruit, (Figure 1, right side). Decreased drupelet set results in smaller berries that do not hold together. These berries can only be sold for processing as juice, puree or jam which reduces the value of the crop.
Leaf symptoms are reported for various cultivars but are not a recommended method for identifying RBD due to their inconsistency. Some genotypes exhibit chlorotic line patterns or general chlorosis on leaves (Figure 2) but these symptoms are not observed on many cultivars grown commercially. When RBDV infects black raspberries, crumbly fruit is also observed.
Figure 3
Detection
ELISA
Symtoms on raspberry are not diagnostic as crumbly fruit can be caused by a variety of different stresses such as root rot, poor nutrition or poor pollination. Therefore reliable detection measures must be used to identify the disease. The easiest and quickest method for detecting RBDV is by using ELISA (Enzyme Linked Immunosorbent Assay). In ELISA plates yellow color indicates an RBDV infected sample was tested in that well.
Figure 4
Another detection method is to inoculate indicator plants such as Chenopodium quinoa or Chenopodium amaranticolor and observing chlorotic leaf spot and mottle symptoms (Figure 4) to verify RBDV infection. This test will differentiate RBDV infection in Rubus spp. from infection by other viruses. nbsp;