Evidence for gene transfer by the use of sublethally irradiated pollen in Zea mays and theory of occurrence by chromosome repair through somatic recombination and gene conversion

摘要: Gene transfer by the use of sublethally γ-irradiated pollen was investigated in Zea mays using three marker genes. Irradiations at 10 and 15 kr produced rare viable T1 seeds which gave rise, usually, to sterile plants. At 5 more were produced, majority rise phenotypically normal, fertile About a quarter resulting (T1) plants showed recessive maternal characters, instead being true hybrids showing dominant characters parent. In effect, different, partial only portion, not all, genome combined with total egg genome. The above results are similar those previously obtained Nicotiana rustica (Jinks et al. 1981) where irradiated sublethal doses used. A new hypothesis is proposed explain gene following pollen. It suggested that divisions during early embryogeny normal fertilisation treated near-lethal radiation, there selection cells irradiation damaged segment paternal chromosomes repaired, through homologous somatic recombination conversion, segments from chromosomes. chromosome repair may be specifically facilitated irradiation-induced sub-chromatid breakage occurs prophase mitotic cells—the usual phase generative gametic nuclei grains time irradiation. mechanism highlights dynamic role single strands ionising radiations timely production such strands.