Munger, H. M.
Campbell Soup Co. No. 222 has been used as the main crack resistant parent in tomato breeding at Cornell. It was originally crossed to John Baer which is extremely susceptible to cracking, and an F3 was backcrossed to John Baer. From this came a progeny designated as 53-548 which had much larger fruit than 222 and surprisingly seemed to have better crack resistance than 222. An earlier generation of 53-548 was crossed with Longred and from this was derived 55-542 which has appeared to have even better crack resistance than either 53-548 or 222.
Attempts have been made to get ratings on cracking in these progenies as compared with 222 but have not succeeded because most of the time our conditions are not severe enough to get appreciable cracking in any of the 3. However, we have occasionally observed considerable cracking in 222 but not in the two progenies, or in 222 and 53-548 but not in 55-542. Trial samples of 55-542 have brought almost unanimously favorable reports on its crack resistance whereas a number of people found considerable cracking in 222.
This apparent increase in crack resistance as successive crosses have been made to susceptible varieties is in sharp contrast to the decline in disease resistance we have usually noticed in similar series of crosses where resistance is not simply inherited. It would seem to indicate that genes contributing to crack resistance may be present in several susceptible varieties.