Natural warfare between a virus and aPseudomonasbacterium is help USDA scientists continue to learn about the bacterium ’s ability to kill arugula , broccoliand several otherbrassica vegetables .
USDA plant pathologist Carolee T. Bull , of the Agricultural Research Service ’s Crop Improvement and Protection Research Unit , and her fellow worker use the computer virus , love as PBSPCA1 , as the basis for a lab test that helps quickly identify crucifer blight bacteriumPseudomonas cannabinapv . ( pathovar)alisalensis .
In on-going inquiry dating back to 1998 , Bull and her co - detective have detected and describe this pseudomonad ; clarified its taxonomy , or “ syndicate tree ; ” and determined that it is the culprit behind crucifer blight , a costly bacterial disease that damages crops in the brassica family . The blight causes water - soaked spots to appear on plant leaves , which finally merge and sour dark-brown , establish the leaf an unattractive , incinerate appearance that makes the vegetable unmarketable .
Early on , the scientists ’ field , greenhouse and laboratory studies point that the cruciferous plant blight bacterium could be easily confused with a airless first cousin , P. syringaepv.maculicola , which causes capsicum pepper plant maculation disease . The two different pseudomonad — both of which are harmless to man — down some of the same veggie crops , and several standard research lab test can not reliably tell the difference between the two bacteria .
Bull and her co-worker choose the PBSPCA1 computer virus as the foundation for a lab assessment that faithfully identifies the two confusing bacteria . Because the virus can kill the cruciferous plant blight bacterium but not the pepper pip pseudomonad , it can be used to mark one bacterium from the other . The researchers began using PBSPCA1 for preliminary diagnoses in 2002 , and have carry on to improve the assessment .
The bacteria that the team later identified as the cause of crucifer blight begin showing up in veggie fields in California ’s Salinas Valley in 1995 . Bull begin investigating the deep microbe three age by and by . Within a few long time , her team had resolved much of the confusion besiege it .
Today , Bull and her co - investigators continue to help growers and plant pathologists in the United States and abroad identify the crucifer blight bacterium . Positive designation weigh , specially when growers are determine what to institute . For example , the USDA studies have shown that Brassica oleracea italica , cabbage and cauliflower are vulnerable to both the crucifer blight and the pepper daub bacteria , while some other crop , such as lettuce , are not .
Read more about this research in the February 2013 issue ofAgricultural Researchmagazine .
