A new source of resistance to phoma stem canker, labelled RlmS, will confer effective and sustainable resistance to the disease, says plant breeder LS Plant Breeding (LSPB).
The company is introducing RlmS to the UK market in two varieties: Respect and Flemming.
Respect is a hybrid set to become a new benchmark for plant health and yield stability, says LSPB.
Along with its resistance to phoma stem canker, it is also said to have a high, consistent yield performance and vigorous growth habit in autumn and spring regrowth.
The variety was added to the AHDB Recommended List (RL) for the East/West region for 2021/22.
Flemming is another first for the UK market as a next generation hybrid with stacked traits, adding turnip yellows virus resistance (TuYV) to the RlmS resistance.
A RL candidate variety, it is due to be considered for addition to the RL this autumn.
Flemming promises the same yield performance and autumn vigour as Respect with a more prostrate growth habit, says LSPB.
Chris Guest, LSPB managing director, explains the innovations behind RlmS.
“This gene was identified by breeders at NPZ, LSPB’s shareholder, who have been researching phoma resistances for decades. It was integrated into our breeding programmes and developed into a viable trait for commercial varieties. Genetics “It is important to note that the RlmS gene is distinct from those widely found in current oilseed rape varieties. Hence, by developing our hybrids with different genetics, we give extended and resilient phoma resistance in the field.”
“The unique phoma resistance is also associated with strong overall plant health and the gene has especially good stem resistance that brings better protection against the increasingly important pathogens of verticillium and sclerotinia. “While cabbage stem flea beetle is seen as the major current threat by growers, it should be emphasised that stem canker/phoma is one of the most important diseases in oilseed rape that has widespread and regular occurrence, taking up to 50% off yield potential.”
It is estimated that total economic losses from the disease reach about £100 million each season.
“The oilseed rape area is set to rebound to sustainable levels this autumn as, by most measures, it is the best break crop on a gross margin basis. The heightened resistance from our new varieties to stem canker/phoma – and added TuYV resistance – will be an important weapon in the armoury of growers.”
Other winter OSR varieties to have emerged from the LSPB breeding programme in recent years have included clubroot resistant varieties Croozer and Crome, plus the HEAR variety Resort, which are all currently on the Recommended List.
“Respect and Flemming are a new and exciting generation of hybrids,” concludes Mr Guest.