The USDA grape rootstock improvement program, based at the Plant Genetic Resources Unit, is breeding grape rootstocks resistant to aggressive root-knot nematodes. We define aggressive root-knot nematodes as those which feed on and damage the rootstocks Freedom and Harmony. In 2003 we screened 4058 candidate grape rootstock seedlings for resistance to aggressive root-knot nematodes. We select only those seedlings which completely suppress nematode reproduction and show zero nematode egg masses. These selected seedlings are propagated and then planted into the vineyard. We have 81 nematode resistant selections that will be ready for vineyard planting in spring 2004. In 2003 we planted 145 nematode resistant rootstock selections in the vineyard. These selections were identified in nematode resistance screening in 2002 and earlier. In 2003 we pollinated 1287 clusters of crosses specifically aimed at the breeding of improved rootstocks with resistance to aggressive root-knot nematodes.
/wp-content/uploads/2017/09/AFV-Header-Logo.png 0 0 AVF /wp-content/uploads/2017/09/AFV-Header-Logo.png AVF2003-10-17 07:48:282017-10-17 07:49:16Breeding rootstocks resistant to aggressive root-knot nematodes