Stripe rust research and control: Conclusions and perspectives

Abstract

Stripe rust is an old problem in world production of wheat and barley. Great progress has been made in understanding the pathogen, the hosts and the disease, especially the pathogen biology, host resistance and epidemiology of the disease. Now, it is clear that Puccinia striiformis has a macrocyclic lifecycle, but mainly reproduces through the asexual cycle. A large number of cereal germplasms and genes for different types of resistance to stripe rust have been identified and used in breeding programs for developing resistant cultivars. At the same time, more fungicides with different modes of action have become available for use to control stripe rust. Nowadays, growers are able to reduce potentially very high yield losses to minimal with an integrated control approach combining cultivar resistance, appropriate use of fungicide and suitable cultural practices. However, there are still many challenges for control of stripe rust. For example, the role of alternate hosts and auxiliary grass hosts in developing stripe rust epidemics and generating pathogen variation is not clear in many regions of the world. Stripe rust resistance has not received adequate efforts in breeding programs in many countries or regions due to various reasons. Chemical control has not become a practical option for growers in many developing countries. Although tremendous progress has been made in research on the genome, functional genomics and marker development for monitoring the pathogen populations, none of the P. striiformis avirulence genes have been cloned and molecularly characterized. Putting these challenges into consideration and research, more progress will likely be made in these areas in the next 10-20 years. Ultimately, the devastating disease can be put under control more effectively.