In this episode we meet Dr. Jenny Davidson, a pulse pathologist at South Australian Research Institute, or SARDI, in Adelaide, South Australia. Dr. Davidson works on diseases of lentils, chickpeas, field peas, and fava beans. She leads a team of a number of scientists and technicians working to keep pulse diseases under control in Australia. In 25 years of doing this work with pulse crops, she has seen diseases and genetic resistance to those diseases come and go. She shares about efforts to combat these pulse diseases, especially ascochyta, and the unified effort in Australia to find effective ways to manage them.
“We started out and still do really have a big focus on ascochyta because each of these crops have their own version of ascochyta blight. And in a rain fed growing system, this has a major impact on the crops.” - Dr. Jenny Davidson
Dr. Davidson shares that chickpeas became popular in Australia in the 1990’s. The varieties used were susceptible to ascochyta blight leading to the loss of whole crops. The industry only began to grow again once resistant varieties were used. Unfortunately, some of those varieties that had demonstrated resistance for 10 years began showing susceptibility. Producers are now having to use multiple fungicide spray applications and consider the additional costs in order to make up for this adaptation.
“What the Australian researchers have done in investigating the pathology of ascochyta rabiei in chickpeas is looking at the population variability of that pathogen, because obviously if you put out resistant types, you’re then putting a selection pressure on the pathogen to create types that can overcome that resistance. So we need to understand what the pathogen is doing.” - Dr. Jenny Davidson
Dr. Davidson’s research has identified that the ascochyta they are facing in chickpeas only reproduces in Australia asexually. Generally this leads to a reduction in the pathogens ability to adapt to resistant varieties but somehow the ascochyta has overcome this and made itself very difficult to manage for producers. The programs to investigate this are coordinated around Australia and the world to isolate the genetic sequences responsible for susceptibility and resistance.
“What we're hoping is that the resistance that we can get into adapted backgrounds then is handed over to the national breeding programs to get it into something that farmers will really want to grow. So it's a complete “beginning to end” program to try and cover off on the whole thing” - Dr. Jenny Davidson