The Combining Ability of Two Degenerative Sweet Com Mutants1

Abstract

Two degenerative sweet corn mutants, C30, a mutant of P39, ‘Pee Wee’ a mutant of C30 and P39 were crossed with each other and with 4 unrelated inbreds to ascertain their relative abilities to promote heterosis in hybrids. In these tests C30 often exceeded P39 in the promotion of hybrid vigor but ‘Pee Wee’ was relatively inefficient in stimulating heterotic effects.

Molecular Variation and F1 Performance among Strains of the Sweet Corn Inbred P39

“…These differences were found to be due to the reduced gene ( rd1 ). Singleton (1943, 1944a, 1947) observed significant high parent heterosis for yield and plant height when C30 was backcrossed to P39 and Lachman (1971, 1974) observed high parent heterosis for plant height in the same cross. Singleton thought this was an example of single gene heterosis and that rd1 was responsible (1943).…”

“…M orphological variants have been observed in a number of long established maize inbreds (Jones, 1944, 1945; Singleton and Nelson, 1945; Russell et al, 1963; Lachman, 1971; Burr and Burr, 1981). Many of the variants were described as being due to mutations at single genes.…”

“…Singleton thought this was an example of single gene heterosis and that rd1 was responsible (1943). However, upon selfing the F 1 of C30 by P39 Singleton (1944b, 1947) observed “several distinct variations,” all of which segregated in “good monogenic ratios.” A diminutive form of C30, Pee Wee, also was isolated (Lachman, 1971) Pee Wee has since been lost.…”