Inter-character relationships and heterosis observed in opaque-2 maize crosses and in their normal analogues

Hybrids obtained from two series of diallel crosses made between six o 2 converted inbred lines on the one hand and their normal analogues on the other were compared for twenty-five characters including yield and several of the yield components, including the parents. Observations on simple inter-character correlation coefficients presented here have shown that the majority of the correlations at the o 2 level are of the same order as at the normal level. A number of correlations of the o 2 type are inferior to those of their normal analogues, whereas a few are favoured by the o 2 gene including the correlation of grain yield with kernels per row. A measure of heterosis for each hybrid over its mid-parent also demonstrated that the o 2 types show poorer heterosis in more cases than do their normal counterparts. Still, in nearly 40 percent of the cases the o 2 hybrids were found to be more heterotic than their normal analogues, particularly for the various maturity characters and several of the yield components. Thus, the possibility of improvement exists in breeding maize with the opaque-2 gene.

Protein quality traits and their relationships with yield and yield components of opaque-2 and analogous normal maize hybrids and inbred lines

Diallel cross hybrids obtained by crossing six opaque-2 (o 2) converted inbred lines were compared with a similar series of crosses made between the analogous normal inbred lines together with the parents, for a number of protein quality and oil traits. The results obtained show that there is only a minor decrease in percent protein or yield of protein per hectare caused by the presence of the o 2 gene in recessive homozygous condition, compared with its normal counterpart. On the other hand, percent lysine in the whole kernel, lysine yield per hectare and percent lysine in protein are increased by 53, 45 and 55 percent, respectively, in the o 2 inbred lines and hybrids compared with their normal analogues. Percent oil and oil yield remain almost unaltered by the presence or absence of the o 2 gene. As well as lysine, the content of other amino acids, such as aspartic acid, arginine, glycine, threonine, valine and histidine are also, in general, increased by the presence of the o 2 gene in recessive homozygous condition.The results obtained have shown that a number of correlation coefficients between the protein quality traits and yield components related to kernel characteristics are negative and significant, especially in the presence of the o 2 gene in recessive homozygous condition. Only two correlation coefficients have been found that could be used with advantage by opaque-2 maize breeders. They are a stronger positive correlation of percent protein with percent lysine, and lysine yield per hectare with 1000 grain weight, in o 2 maize than in normal maize.The results presented here also show that there is more heterotic dilution in the o 2 hybrids than in the normal analogues for traits like percent protein, percent lysine (whole kernel basis) and percent lysine in protein. It has been observed that the inbred lines with the o 2 gene in recessive homozygous condition and a superior protein quality tend to produce hybrids of superior quality.

The treatment of precocious puberty with cyproterone acetate

Nine patients (8 girls and 1 boy) suffering from precocious puberty received daily 100 mg/m2 cyproterone acetate orally. This treatment inhibited the vaginal bleeding; breast-size and the axillary hair and pubic hair did not further increase. The height increment per year and the bone maturation slowed down. The urinary excretion of androgens was temporarily diminished. It is probable that the growth prognosis could be improved by the administration of cyproterone acetate.