After 100 years, Cornell University plant pathologists revisit fire blight hypothesis

After 100 years, Cornell University plant pathologists revisit fire blight hypothesis
Fly feeding on the ooze droplet in the experimental chamber. Credit: Matthew Boucher

Historically credited as being the first bacterium ever characterized as a plant pathogen, fire blight is a bacterial disease that leads to significant losses of pear and apple. The role of insects in the spread of this disease has been long studied. In a new study, plant pathologists based at Cornell University and Cornell AgriTech take a hypothesis that has been more or less ignored for 100 years and provided support for its validity.


According to first author Matthew Boucher, the study describes a long hypothesized but never experimentally supported transmission mechanism for fire blight. Boucher and colleagues show that flies in an apple orchard can acquire the bacterial agent (Erwinia amylovora) of fire blight from sugary droplets exuding from diseased apple trees and subsequently transmit the bacterium to uninfected shoots so long as those

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Indian fossils support new hypothesis for origin of hoofed mammals — ScienceDaily

New research published today in the Journal of Vertebrate Paleontology describes a fossil family that illuminates the origin of perissodactyls — the group of mammals that includes horses, rhinos, and tapirs. It provides insights on the controversial question of where these hoofed animals evolved, concluding that they arose in or near present day India.

With more than 350 new fossils, the 15-year study pieces together a nearly complete picture of the skeletal anatomy of the Cambaytherium — an extinct cousin of perissodactyls that lived on the Indian subcontinent almost 55 million years ago.

Among the findings includes a sheep-sized animal with moderate running ability and features that were intermediate between specialized perissodactyls and their more generalized mammal forerunners. Comparing its bones with many other living and extinct mammals, revealed that Cambaytherium represents an evolutionary stage more primitive than any known perissodactyl, supporting origin for the group in or near India

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