Chromosomes in hybrids between Euchlaena perennis and Zea mays
Journal of Agricultural Research (Washington, D.C.) 48(9): 789-806
ISSN/ISBN: 0095-9758 Accession: 024330202
The number of chromosomes in gametes of various perennial teosinte-maize hybrids depends upon the regular distribution of all paired chromosomes and the random distribution of all unpaired chromosomes during meioses. The random distribution occurs in the 1st division except the rare cases in which univalents divided in the 1st division, when it then occurs in the 2nd division. The chromosome number of functioning pollen shows a marked tendency to be euploid, while that of functioning ovules shows only a slight tendency toward the euploid numbers 10 and 20. If at meioses autosyndesis has been the rule and only euploid gametes have functioned, all diploid derivatives will be homozygous as well as true-breeding and all tetraploid derivatives will be heterozygous but true-breeding. If, however, allosyndesis occurs, both diploid and tetraploid derivatives may contain desirable combinations of parental characters, but plants homozygous for such characters are more readily derived from the heterozygous diploid than from the heterozygous tetraploid form.