TABLE 2.
Willow clone cuttings tested for the presence of B. salicis bacteria in their vascular fluida
| Clone no. (species) | Symptoms of watermark disease
|
|
|---|---|---|
| External | Internal | |
| 89.036/52, 89.036/53, 89.036/54, 89.036/55, 89.036/57, 89.036/58, 89.036/59, 89.036/60, 89.036/63, 89.036/66, 89.036/67, 89.036/71, 89.036/72, 89.036/74 (half-sibling S. alba) | No | NDb |
| 89.036/56, 89.036/62, 89.036/64, 89.036/68, 89.036/69, 89.036/73 (half-sibling S. alba) | Yes | ND |
| 89.001/47, 89.001/58, 89.001/79 (S. alba × S. alba) | No | ND |
| 89.001/43, 89.002/24 (S. alba × S. alba) | No | Yes |
| 89.018/6, 89.018/13, 89.018/17, 89.018/18 (S. rubens × S. alba) | No | ND |
| 89.018/20, 89.018/27, 89.018/4, 89.018/20 (S. rubens × S. alba) | No | Yes |
| 89.018/2 (S. rubens × S. alba) | Yes | Yes |
a
The cuttings were planted in 1992 and artificially infected with B. salicis in 1993. Vascular fluid was taken in September 1997. All clones revealed the 553-bp band after PCR amplification with the primer pair Es1a-Es4b.
b
ND, not determined.