Tobacco mosaic resistance in S. pennellii.<p>

Smith, P. G.<p>

Solanum pennellii, 59L366 (LA716), secured from C. M. Rick, has shown a high
level of resistance to tobacco mosaic, which is different from the resistance
exhibited by the TM1 and TM2 genes. When crossed with L.  esculentum, the
appearance of visible symptoms of mosaic in resistant segregates is delayed
from 4 to 6 weeks, as compared to susceptible check plants, and symptom
expression is extremelly mild.  Usually a faint mottle can be observed on
older leaves and little or none on immature leaves.  Identical symptom
expression occurred whether inoculated with U.C.  (Berkeley) Virus Lab. strain
of TMV or a local "wild" strain, while the TM2 gene confers resistance to the
former but not to the latter.<p>

Data at present are not adequate to determine definitely the inheritance of
resistance. F2 and backcross populations with esculantum indicate that the
complementary action of 3 dominant genes may be necessary for resistance.<p>

<!--GH_SEARCH-->
<!--GH_END-->