Reproductive peculiarities of maize-tripsacum hybrids in connection with the effect of ionizing radiation

The radiation treatment of seeds of highly apomictic forms of maize-tripsacum hybrids (at backcrosses with maize) is not an effective means to increase the yield of reduced hybrids. X-rays and #betta#-irradiation (10 kR irradiation dose) were used in the experiments with the highly apomictic form of the hybrid (2n=38). Though about 1.5 thousand plants had been studied only 2 reduced hybrids were found; the first plant was separated in the posterity from #betta#-irradiated plants, and the second hybrid - from X-irradiated plants. In the pollination variant which was more widely represented in the experiment #betta#-treatment was accompanied by a trustworthy numerical increase of non-reduced hybrids which could be explained by an unequal reaction of apomixis elements to the effect of #betta#-radiation: a high stability of the first element - the ability to form non-reduced female gametophytes, and lesser stability of the second element - the ability to parthenogenesis. This is possibly connected with a lower stability of a gene or genes controlling the parthenogenesis but it is excluded that a short-time physiological effect is in the basis of this phenomenon