Comparison of ihe Tryptic Peptides of Wild Strains of Tobacco
              Mosaic Virus

J'lutants of tobacco mosaic virus (T,111') derived under experimental
conditions from the normal TMV strain ~wlgar~ show only minute differ-
cows, if any: one or only a few amino acids may be replaced by others.
Iktsides these mutants R number of T>lV-strains are lalown whose rela-
t ionship to udgaw is not clew txwuse they were found in nature. Thcsc
strains show many biological differences when compured with the normal
`~,\I\~' strain; it is thtwforc interesting to study Ithat chemicul differ-
cnces exist, amoiig them.

One of these wild T,\l\: strains is dahlemetw, isolntcd by Xlclchc~s (I)
from tomato plants about twenty years ago. In contrast to the mutants
derived from vr~lyare, which all produce local lesions on I'haswlus rlrl/-
gnu's, rlnhlcm~~nsr does not give lesions on this plant. It show green sys-
tcmic symptoms on "Samsun tobacco" a11d produces local lesions on
".I:Lw tobacco". Its serologk~l behavior is quite different from that of
the vdgare strain or its mutants (2, c). l"igure 1 shows the electrophorrtic
mobility of whole virus and corresponding derived A protein of ~~lyare,

8     9


  I
Vulgare

0     30    60    90         150    180    210

Dahleyense