DISEASE CONTROL IN MILKWEED-SPECIES AND ECOTYPE SELECTION

WE PROPOSE TO TEST THREE SPECIES OF MILKWEED AND THEIR ECOTYPES IN THE GREEHOUSE FOR RESISTANCE, TOLERANCE OR BOTH TO BLACK SPOT AND BACTERIAL BLIGHT CAUSED BY THE FUNGAL PATHOGEN, CERCOSPORA SP. AND XANTHOMONAS CAMPESTRIS PV ASCLEPIADIS. THESE TWO DISEASES ARE THE PRINCIPAL OBSTACLES TO THE ESTABLISHMENT OF A COMMERCIAL MILKWEED INDUSTRY. THEY CAM REDUCE THE YIELD OF FLOSS BY 75%. RESULTS FROM SOME PRELIMINARY STUDIES IN THE GREENHOUSE AND OBSERVATION IN THE FIELD INDICATE THAT SOME OF THE ECOTYPES OF TWO SPECIES OF MILKWEED, ASLEPAIS SYRICA, A. SPECIOSA AND A VIRIDE MAY PROVIDE RESISTANCE TO THESE TWO DISEASES. HOWEVER, A RIGOROUS TEST IN THE GREENHOUSE INVOLVING AN ENVIRONMENT CONDUCIVE TO THE DEVELOPMENT OF BLACK SPOT AND BACTERIAL BLIGHT IS REQUIRED TO DETERMINE WHETHER THE TWO SPECIES OF MILKWEED POSSESS TRUE RESISTANCE TO THESE DISEASES. METHODS HAVE BEEN SUCCESSFULLY ESTABLISHED FOR GROWING INOCULUM AND FOR INOCULATING AND INFECTING MILKWEED PLANTS WITH THE PATHOGENS OF BLACK SPOT AND BACTERIAL BLIGHT. THUS, THIS PROJECT WILL FOCUS ON COLLECTING AND ANALYZING THE RESPONSES OF THE THREE SPECIES OF MILKWEED. INFORMATION GAINED FROM THIS STUDY WILL PROVIDE THE BASIS FOR FIELD TESTING OF PROMISING ECOTYPES OF THE THREE SPECIES OF MILKWEED FOR RESISTANCE TO BLACK SPOT AND BACTERIAL BLIGHT. A FIELD DISEASE NURSERY HAS BEEN ESTABLISHED FOR CONDUCTING SUCH STUDIES IN A PHASE II EFFORT.