An F2 of the hybrid between diploperennis and WMT corn yielded 217 plants
that were scored for Su su, Gl gl, Lg lg and evergreen vs. dead stalks.
The data are as follows:
Su | su | Gl | gl | Lg | lg | Observed Total | Expected 9:7 | d2/e | |
Evergreen | 105 | 14 | 97 | 29 | 100 | 26 | 126 | 121 | 0.206 |
Dead | 57 | 41 | 68 | 23 | 64 | 27 | 91 | 96 | 0.260 |
Totals | 162 | 55 | 165 | 52 | 164 | 53 | 217 | 217 | 0.466 |
X2 = 0.466 with a probability of ca. 50% at 1 d.f. In other words, the observed does not differ significantly from a 9:7 ratio.
It is probable that the evergreen stalk is at least one component in perennialism and that its inheritance is at least partially controlled by two dominant complementary genes. Of the various WMT marker genes involved in the F2 segregation, three were scored (su, gl, lg) for possible linkage with perennialism. Glossy and liguleless segregated independently but the segregation of sugary-starchy is grossly distorted by the separation into the evergreen vs. dead classes. The sugary class is low in evergreen stalks and high in dead stalks while starchy is the reciprocal. Therefore it seems that one component of the perennial trait is located on chromosome 4.
Previously, D. L. Shaver (MNL 46:20, 1972) has suggested that three genes (id, gt, pe) may control perennialism. Perhaps a fourth trait of complex inheritance that produces vegetative dormancy under drought stress may be carried by diploperennis. This trait termed "latente" was first identified in Michoacan 21, as reviewed by Castleberry and Lerette (1979) of DeKalb AgResearch.
Walton C. Galinat
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