- 5 - 
EPIDEMIC TO OCCUR YOU MUST SIMULTANEOUSLY HAVE LARGE NUMBERS OF SUSEPTIBLE 
PLANTS IN ONE LOCATION, JUST THE RIGHT WEATHER CONDITIONS AND HIGH POPULA- 
L AT IONS OF THE PATHOGEN. AS A RESULT PLANT PATHOGENS GENERALLY HAVE 
RESTRICTED HOST RANGES AND GEOGRAPHIC DISTRIBUTION. CONSEQUENTLY, I BELIEVE 
THAT IT SHOULD BE JUST AS SAFE TO WORK WITH THE RECOMBINANT DNA MADE FROM 
PLANT PATHOGENS AS IT IS TO WORK WITH THE PATHOGENS THEMSELVES. 
I HAVE SPOKEN WITH A NUMBER OF PLANT PATHOLOGISTS CONCERNING THE PROPOSED 
REVISIONS AND ALL OF THEM ARE ANXIOUS TO SEE THE NEW GUIDELINES IMPLEMENTED 
AS SOON AS POSSIBLE. WHEN THE PROPOSED REVISED GUIDELINES ARE ACCEPTED 
THERE WILL CERTAINLY BE AN INCREASE IN THE NUMBER OF PLANT SCIENTISTS USING 
THIS TECHNIQUE AND THE BENEFITS TO AGRICULTURE COULD BE TREMENDOUS. I, FOR 
ONE, WOULD LIKE TO USE CLONING TO ESTABLISH THE RELATIONSHIP BETWEEN PLASMIDS 
AND VIRULENCE IN ERWINIA STEWART I I , AN IMPORTANT PATHOGEN OF CORN. 
ON BEHALF OF OTHER PLANT PATHOLOGISTS, I STRONGLY URGE THIS COMMITTEE AND 
SECRETARY CALIFANO TO ACCEPT THE PROPOSED REVISED GUIDELINES AT THIS TIME 
SO THAT THERE WILL BE NO FURTHER DELAYS IN BEGINNING IMPORTANT RESEARCH ON 
GENETIC IMPROVEMENT OF CROPS, NITROGEN FIXATION, AND PLANT DISEASES AND OUR 
UNDERSTANDING OF THE ORGANISMS INVOLVED. 
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