Young, P. A.
Round, downward curled and wrinkled leaves 1/4 to 3 cm. wide, almost without petioles, developed in densely compact clusters on one stem of a Stokesdale tomato plant that also had 2 normal stems in September 1953. The stem with the curl-leaves was apparently unbranched as the branches and lateral leaves remained small rosettes on the stems. Most of the curl-leaves appeared reduced to their terminal leaflets, but some had a few lateral leaflets a few mm. long. The branch with the curl-leaves bore 2 fruits, the seeds from which produced 11 normal plants and 44 typical curl-plants. The cotyledon leaves were normal on all plants. However, the first true leaves were typically curled and crinkled on the abnormal plants, making the seedlings distinctive.
Curl-plants were crossed with 6 normal Rutgers and Marglobe tomatoes. Their F1 descendents showed a total of 87 curl-plants and 83 normal plants. This resembles a 1:1 back-cross ratio and indicates that the parent G1666 plant was heterozygous. Like the parent, the descendent curl-plants remained apparently branchless and the tops were little rosettes. The plants were weak and grew less than 1/4 as much as the normal plants. They remained dwarfed with the longest stems becoming only 1 m. long. They remained single stems during the first 6 or more weeks. Curl-plants are to be studied through the F2 and F3 generations. They do not resemble tomatoes with the d, dm, or br alleles. The internodes are not apparently shortened. This new example of tomato teratology came from a probably dominant mutation for which the symbol, Cu, is suggested.