Mutations for chlorophyll retention in ripe fruit.
Kerr, E. A.
Following reports of the gf, green flesh (Kerr, TGC6:17), and Nr, never ripe (Rick, TGC6:22) mutants, three other somewhat similar mutants, which arose independently, were sent to Vineland for test. These were No. 274 from Thompson of the University of Illinois (TGC7:15), No. 54-1293-4 from Paddock of Ohio State University and the variety Evergreen from Glecklers Seedsmen, Metamora, Ohio. Various crosses were grown in 1957. The table gives the resulting phenotypes.
Cross Ripe Fruit Type Evergreen X green, no red - gf, r Evergreen x gf r green, no red - gf, r Evergreen x r green disappears, - gf^+, r no red Evergreen x gf green + red - gf, r^+ Evergreen x No. 274 green + red - gf, r^+ Evergreen x No. 54-1293-4 green disappears, - gf^+, r^+, gr^+ red gf X green + red - gf gf x No. 274 green + red - gf gf x normal green disappears, - gf^+ red gf x No. 54-1293-4 green disappears, - gf^+, gr^+ red gf x Nr green partly - Nr disappears No. 274 X green + red - gf No. 274 x normal green disappears, - gf^+ red No. 274 x No. 54-1293-4 green disappears, - gf^+, gr^+ red No. 274 x Nr green partly - Nr disappears No. 54-1293-4 X outer wall green, - gr center red No. 54-1293-4 x normal green disappears, - gr^+ redThese data indicate (1) that Nr is the only dominant mutant in this group, (2) that No. 274 and Evergreen both have the gene gf and (3) that chlorophyll retention in No. 54-1293-4 is recessive.
An F2 population of the cross gf a c d r y x No. 54-1293-4 was grown in pots in the greenhouse. Inconclusive results on the inheritance of chlorophyll retention in No. 54-1293-4 were obtained. The tests will be continued inder field conditions where a succession of maturities on each plant can be compared.
Paddock (personal communication) reports that his green-fruited mutant first appeared in 1952 in a chimeral fruit having green and red sectors. He and Alexander propose the name "green ripe" for the mutant with gr as the gene symbol.