| Abstrakt: |
A maize (Zea maysL.) seed stock with a modified endosperm type was isolated from a homozygous opaque‐2 line. Allelic tests with known single gene endosperm markers showed that the genotype was su2/su2, o2/o2. The genotypic constitution of this isolate was further confirmed by an allelism test with two known double recessive types as su2/su2,o2/o2, testers. The endosperm had a higher percentage of lysine per unit of protein than both the typical opaque‐2 endosperm corn used as a check and those values reported in the literature. The endosperm of this stock is translucent, of hard texture, and somewhat discolored and dull; it has a kernel density similar to the normal endosperm corn. Kernel weights of the S2progenies segregating at the su2/su2, and o2/o2loci indicated that the kernel weight of the double mutant endosperm combination su2/su2,o2/o2was 92 to 93% of that of the opaque‐2 class. The differences in kernel weights were explained as the results of the effects of the opaque‐2 gene on the sugary‐2 endosperm types which are already below the mean of normal endosperm corn. Observed kernel weight variability between and within progenies suggested the possibility for selection of kernel weights within the levels of sugary‐2 as well to levels similar to normal and opaque‐2. The double recessive type (su2/su2,o2/o2) had increased lysine as percent of protein and improved kernel properties in comparison to opaque‐2 corn. |
Plný text