Race status, resistance mechanisms, and new sources of resistance to Phytophthora clandestina, a major threat to subterranean clover production. Devastating outbreaks of disease caused by Phytophthora clandestina (Phytophthora root rot) since the late 1970s demonstrated the capacity of this disease to impact severely on clover pasture production across southern Australia, particularly as new races of Phytophthora have rapidly emerged to overcome the resistance of all commercial cultivars. The p ....Race status, resistance mechanisms, and new sources of resistance to Phytophthora clandestina, a major threat to subterranean clover production. Devastating outbreaks of disease caused by Phytophthora clandestina (Phytophthora root rot) since the late 1970s demonstrated the capacity of this disease to impact severely on clover pasture production across southern Australia, particularly as new races of Phytophthora have rapidly emerged to overcome the resistance of all commercial cultivars. The proposed research seeks to delineate new races of the pathogen, to identify the histological and biochemical mechanisms by which resistance to Phytophthora root rot is expressed, and to identify new sources of host resistance. This proposed research will enable breeders, for the first time, to incorporate multiple types of resistance and against different races into new host varieties.Read moreRead less
Molecular, physiological and environmental regulation of toxic prussic acid levels (cyanogenesis) in forage sorghum. Forage sorghum is grown widely in dry, tropical areas of Australia. The leaves contain dhurrin, a natural defence product that liberates prussic acid (cyanide) when leaf tissue is disrupted (eg when chewed). The problem is that young plants or those experiencing drought are highly toxic, resulting in financial loss through reduced nutritive value, livestock loss and wasted feed. U ....Molecular, physiological and environmental regulation of toxic prussic acid levels (cyanogenesis) in forage sorghum. Forage sorghum is grown widely in dry, tropical areas of Australia. The leaves contain dhurrin, a natural defence product that liberates prussic acid (cyanide) when leaf tissue is disrupted (eg when chewed). The problem is that young plants or those experiencing drought are highly toxic, resulting in financial loss through reduced nutritive value, livestock loss and wasted feed. Using new, non-GM technology we will identify novel genetically altered sorghum lines with negligible prussic acid. Lines with enhanced levels could be used as soil biofumigants. Breeders can use this germplasm to develop varieties tailored for increasingly dry Australian conditions. The new varieties with controlled dhurrin content will be suitable for export.Read moreRead less
Phytoremediation of arsenic contaminated sites using arsenic hyperaccumulating plants. The legacy of using arsenical compounds in pest control activities has resulted in many contaminated sites. Since the inorganic arsenic is carcinogenic, stringent laws have been enforced to control arsenic (As) in the environment. This project investigates the potential of using the recently discovered (Ma et al, 2001) arsenic hyperaccumulating (22,000 mgAs/kgDW) fern, Pteris vittata, in the removal of arsen ....Phytoremediation of arsenic contaminated sites using arsenic hyperaccumulating plants. The legacy of using arsenical compounds in pest control activities has resulted in many contaminated sites. Since the inorganic arsenic is carcinogenic, stringent laws have been enforced to control arsenic (As) in the environment. This project investigates the potential of using the recently discovered (Ma et al, 2001) arsenic hyperaccumulating (22,000 mgAs/kgDW) fern, Pteris vittata, in the removal of arsenic from dip sites and railway tracks in Qld, and orchards in northern NSW. The impacts of growing hyperaccumulating plants on grazing animals and the environment, and the disposal of arsenic from contaminated plants will also be studied.Read moreRead less