Speeding the breeding of phoma-resistant oilseed rape

Selection of oilseed rape varieties with quantitative genetic resistance to phoma has so far relied on assessment of crop disease severity at the end of growing season.

It has been difficult to investigate quantitative resistance against the growth of this pathogen in leaves and petioles or in stems before the appearance of stem canker symptoms under field crop conditions due to the long period of symptomless growth after initial leaf infection.

However, this could change following publication of A University of Hertfordshire study which looked at whether resistance can be assessed in young oilseed rape plants.

Yongju Huang, reader in plant pathology at the University of Hertfordshire, says: “If so, it will accelerate the process of breeding oilseed rape crops for resistance. It will also save money by reducing the number of pre-breeding lines needed for testing in field experiments, based on results of disease resistance assessments in young plants.

“Results of our research show that there are good correlations between resistance detected in young plants in controlled environment experiments and resistance detected in adult plants in field experiments. This suggests that resistance can be assessed in young oilseed rape plants.”