Study of possibility in raising maize inbred lines with two embryos

Ears having 1 to 3 kernels with two embryos were found in a synthetic and local maize population at the Maize Research Institute, Beograd-Zemun, in 1963-1964. From this material, using the method of individual kernels, selection was initiated and inbred lines with two embryo kernels were obtained.The present paper gives the results of further breeding of maize lines having two embryo kernels, the frequency and variability of this occurrence within and among lines, and the results of some cytogenetic investigations of plants originating from two embryo kernels.The frequency of two embryo kernels in ears of 12 selected lines in 1973 varied between 2.1% (the line IT) and 25.3% (the line lab). The average for all lines was 11.8%. The best inbred lines have 8 times the number of kernels with two embryos found for the initial material (3.1%). Compared with normal kernels of the same lines, two-embryo kernels have a considerable increase in protein (4-6%), lysine g/l00 g of dry matter (38- 70.9%), lysine g/ l00 g of protein (21.3-34.0%) and oil (3.5-13.6%).The presence of univalent chromosomes at metaphase I is not relatively high and in most cases it occurs in approximately 10-20% meiocytes, indicating partial desynapsis. No obvious differences in the frequency of univalent chromosomes at metaphase I and lagging chromosomes at anaphase I were found between plants of various height originating from the same kernel.