Chantelle Webb1, Alan Stewart2, Martin Harmer1
1 PGG Wrightson Seeds, 4 Black Swamp Road, Leigh Creek, VIC, 3352, www.pggwrightsonseeds.com.au/Research, CWebb@pgwseeds.com.au,
2 PGG Wrightson Seeds, PO Box 3100 Christchurch 8015
Crown rust (Puccinia coronata f. sp. lolii) is a major disease of perennial ryegrass (Lolium perenne), causing reduced forage yield, plant rooting depth, sward content in mixed pastures, animal intake and digestibility and is associated with animal health problems such as facial eczema. The crown rust resistance (CRR) of contemporary perennial ryegrass cultivars commercially available in Australia has not been studied. Utilising CRR data collected in nine trials over an eight-year period at Ballarat, Victoria, the CRR of 48 commercially marketed varieties were explored. Significant (p<0.001) variation for CRR was identified between marketed perennial ryegrass varieties and the CRR ranking determined for older cultivars and ecotypes was consistent with available literature. Large variation was found in varieties of varying germplasm origins and improvements over older varieties was not large. We suggest progress for this trait may have been temporarily checked by the industries transition to new germplasm sources for other benefits. On average, breeding lines were superior to commercial varieties indicating future improvements are likely. The results of this study suggest that an independent CRR could be easily developed to assist producers choosing between marketed cultivars.