Breeding low glucosinulates varieties of oilseed rape has led to increased slug palatability, according to a study by the John Innes Centre.
Looking to identifying genetic feeding preferences for slugs in oilseed rape, the study found that when six wild slugs were starved for 24-hours and then placed in a choice chamber with five different varieties of plant matter to consume, plants without the HAG1 gene, which controls glucosinolate levels in OSR, were at much higher risk of attack.
Consumption figures between the varieties, which included swede, kale and Chinese oilseed rape, ranged from 10-100 per cent and when slugs were then put in feed chambers with a single plant variety, results were the same.
Presenting the findings of the study at the BCPC Pests and Beneficials Review at Rothamsted Research, Dr Rachel Wells said: “The high aliphatic glucosinulate one (HAG1) gene controls the level of aliphatic glucosinulates that the plant produces. In a lot of breeding material and material you get in the field, because it is low glucosinulate, that locus and the surrounding area has been deleted.
“It is this gene that we have knocked out to get our low glucosinulate OSR, so we have actually bred slug palatability into the material we have in the field.”
Theoretically in brassica you could produce glucosinulates in the leaves but prevent them from being transported to the seeds because the control of glucosinulates in the leaves and in the seeds are different, said Dr Wells.
“However, this will not give the plant protection at the cotyledon stage because the glucosinulates that go into the seed are in the cotyledons at that early stage, and until you get a true leaf, there would be no protection.”