AR128 - a new Epichloë fungal endophyte product for ryegrass

Abstract

Perennial ryegrass (Lolium perenne) persistence and yield in many parts of New Zealand is critically reliant on its association with mutualistic fungal endophytes of the genus Epichloë.  Epichloë spp. can protect their host plants from insect pests and improve tolerance to drought. Over the last 25 years several novel endophyte strains have been commercialised. While ensuring effective persistence of ryegrass, they have also minimised the negative impacts on livestock of ryegrass staggers, heat stress and productivity losses associated with the standard endophyte strain. A new endophyte product is becoming available – AR128. This Epichloë sp. LpTG-3 strain originated from Italy and has a similar known chemical profile to AR37, through expression of epoxyjanthitrems. AR128 protects the host ryegrass plant against the same insect pests as AR37. It also exhibits similar animal safety to that of AR37. However, AR128 transmits through seed production cycles at a greater frequency than AR37 and it also stores for a longer duration in seed at ambient temperature and humidity conditions. These features ensure that the end-user farmer obtains a high quality and effective product, which should ensure improved perennial ryegrass persistence and production compared to endophyte-free grasses and possibly other endophyte strains which are less amenable to transmission and storage. The human consumer of products derived from animals feeding on ryegrasses with AR128 can be assured that there are no food safety issues associated with this technology based on mouse feeding studies.