Poster Presentation Science Protecting Plant Health 2017

Pre-breeding efforts for resistance to Ascochyta blight and Botrytis Grey Mould in pulses (#147)

Pragya Dr Kant 1 2 , Tony Dr Slater 2 , Garry Dr Rosewarne 2
  1. Department of Environment and Primary Industries, Biosciences Research Divison, Horsham
  2. Department of Economic Development, Jobs, Transport and Resources, Horsham, VIC, Australia

Pulses are important protein rich foods for millions of people in South Asian countries and are increasing in importance in Australian cropping systems; not only as a break crop but also providing high farm-gate returns in many regions. Fungal diseases cause major losses in pulse production especially in conducive environmental conditions in susceptible varieties. Ascochyta blight (AB) in field peas and Botrytis Grey Mould (BGM) in chickpeas and lentils consistently cause yield losses. A dedicated pre-breeding effort is being undertaken to develop new and resistant varieties for Australian growers. Reliable, high-throughput, controlled environment screening methods for these diseases have been developed to select for new sources of resistance. Over 1000 landraces and wild relatives of chickpea and lentil germplasm have been screened. In both crops, several lines were identified with partial resistance equal to the best performing current varieties. To further improve resistance, an intercrossing and recurrent selection strategy is being adopted.

            In Australia, AB is caused by a complex of up to four organisms, with Peyronella pinodes and Phoma koolunga being most common. There is very little resistance for the complex in field pea germplasm with the best performing lines scored as moderately susceptible. However this is a step up from early lines that were considered susceptible. A multi environment analysis (MET) of disease scores over several years highlighted two major rankings of germplasm corresponding to trials in either Western Australia or eastern Australia. This has facilitated the selection of germplasm for intercrossing to improve overall levels of resistance and stability. Resistance x susceptible crosses were also made for the genetic characterization of resistance to this disease. Furthermore, microscopic studies were conducted to analyse differences between the most common pathogens and found that P. pinodes is more aggressive than P. koolunga under controlled environment conditions.