The use of irradiated pollen for differential gene transfer in wheat (Triticum aestivum)

Abstract

The use of irradiated pollen to bring about limited gene transfer in wheat has been investigated. Doses of X-rays of 2Kr, 3Kr and 5Kr were used to generate M1 progeny between maternal and paternal genotypes differing in quantitative and major gene characters. Cytological studies of M1 plants revealed hybrids with widespread aneuploidy and structural rearrangements in the paternal genome. These effects resulted in phenotypic variation between M1 progeny and complex multivalent formation at meiosis. All M1 plants at the 5Kr and 3Kr doses were sterile and all but 2 plants at the 2Kr dose.Studies of the two M2 families from these plants revealed disturbances in genotype frequencies for some of the marker loci with an excess of maternal homozygotes and a deficit of paternal homozygotes. This was also reflected in a more maternal appearance for quantitative characters. These results are interpreted as showing that irradiation damage to the paternal genome in M1 plants results in the differential transmission of maternal alleles.

Gene transfer through the use of sublethally irradiated pollen: the theory of chromosome repair and possible implication of DNA repair enzymes

“…Experiments in barley, Hordeum vulgare (Powell et a!., 1983), wheat, Triticum aestivum (Snape et aL, 1983) and Indian mustard, Brassica juncea (Banga et a!., 1984), gave similar results to those with N. rustica and Z mays. There was maternalisation of Ml and M2 progenies, which increased with dose.…”

“…The concept that the radiation-damaged segment of the paternal genome (deletions, mutations and chromosome rearrangements) which would survive and be expressed in the Ml but would normally be eliminated at the Ml meiosis and thus might account for high maternalisation of M2, as compared to unirradiated F2, (Zamir, 1983;Snape et a!., 1983;) also appears to be untenable for, in general, most observations have shown that the extent of variation in the Ml and M2 is in fact related. Significantly, it does not account for the maternalisation of Ml plants themselves.…”

“…Reported transfer of single genes (Pandey, 1975(Pandey, , 1978(Pandey, , 1980a(Pandey, , b, 1981 or a part of the male nuclear complement rather than the whole male nucleus Pandey, 1983a;Powell et a!., 1983;Snape et a!., 1983;Zamir, 1983;Banga et a!., 1984;Caligari et a!., 1984;Davies, 1984;Daskalov, 1984), between one plant and another by the use of irradiated pollen is of considerable interest to the plant breeder. The procedures, when better understood, have the potential of not only considerably expediting plant, and possibly animal (Pandey, 1980c;Pandey and Patchell, 1982) breeding but also producing desirable recombinants which could not be produced before because of close linkage between desirable and undesirable genes, or because of inviability of the normal hybrid zygotes or complete sterility of the normal hybrids.…”

Analyse des plantes de melon (Cucumis melo L) issues de croisements avec du pollen irradié à différentes doses

“…Il a souvent été constaté que la dose d'irradiation appliquée au pollen joue un rôle essentiel dans l'efficacité de la technique. Ainsi, généralement, des hybrides de phénotypes souvent anormaux et stériles (Powell et al, 1983;Daskalov, 1984; Engvild, 1985;Sari Gorla et al, 1987), résultant vraisemblablement d'un état d'aneuploïdie de leur contenu chromosomique nucléaire (Snape et al, 1983), sont obtenus à faibles doses. Lorsque la dose d'irradiation augmente, ces hybrides disparaissent progressivement au profit des haploïdes (Pandey et Phung, 1982;Raquin, 1985;Zhang et Lespinasse, 1991).…”

Irradiated pollen selfs in cultivars of Hordeum vulgare

“…Experiments with several different plant genera have demonstrated that irradiation of pollen prior to fertilisation gives plants (M1 generation) whose progenies (M2) differ from normal crosses (F2) by expressing only a portion of the paternal genome (e.g., Pandey, 1975 and1980;Caligari, Ingram and Jinks, 1981;Powell, Caligari and Hayter, 1983;Snape, et a!., 1983 andDaskalov, 1984). Various mechanisms have been proposed to explain the observed results and these are discussed by Caligari, Powell and Hayter, 1984.…”