Endosperm response to pollen irradiation in kiwifruit

Abstract

Cytological details of endosperm development after pollination with irradiated pollen were studied in Actinidia deliciosa (kiwifruit) cultivar Hayward. Pollinations were carried out involving five different sources of pollen (Matua, Tomuri, Burt, Berryman, and fruiting male) irradiated with gamma rays at doses of 700 and 900 Gy. Non-irradiated crosses were used as controls. Irradiated pollen induced development of approximately 25-30% of the ovules. Two types of ovules were observed: (1) with both embryo and endosperm and (2) with endosperm only. No mitotic abnormalities were found in control or irradiated endosperms. Mitotic divisions were regular and nuclei spherical and evenly spaced. However, the cells of irradiated endosperm usually contained low amounts of storage products. Ploidy level of the endosperms was evaluated by nuclear size (volume) with the use of image analyzis. Mean nuclear size in control and irradiated endosperms was 1598.3 and 750.9 µm 3 , respectively. It is concluded that endosperm produced after pollination with irradiated pollen is autonomous and represents the 2n level.

Endosperm Tolerance of Paternal Aneuploidy Allows Radiation Hybrid Mapping of the Wheat D-Genome and a Measure of γ Ray-Induced Chromosome Breaks

“…In seeds, most radiation dosage studies have focused on the effect of radiation on embryo development while largely ignoring endosperm development [28], [29]. However, in Actinidia deliciosa, the proportion of seeds containing only endosperm, produced following pollen irradiation (900 Gy), was almost ten-fold higher (22.8%) than those containing both (2.8%) embryo and endosperm [30]. The independent response of embryo and endosperm development and apparent high tolerance of endosperm for paternal chromosomal aberrations suggested an alternate route of RH mapping panel development in plants.…”

A one–step organelle capture: gynogenetic kiwifruits with paternal chloroplasts

“…Consequently, a strong bias in favour of the elimination of the paternal chromosomes is plausible here, particularly considering that the paternal chromosomes must have been damaged by irradiation. However, the finding of diploid (instead of triploid) endosperm after pollination with irradiated pollen in kiwifruit (Musial & Przywara 1999) could indicate that double fertilization has not occurred. Figure 3 replacement can be achieved within one generation in Actinidia in the absence of significant nuclear exchanges, following pollen irradiation.…”

“…Most, if not all, of the haploids inherit the chloroplast genome from their father. The endosperm (2n) develops autonomously (Musial & Przywara 1999). cp, chloroplast genome; nu, nuclear genome.…”

Induction of haploid plants in citrus through gamma-irradiated pollen and ascertainment of ovule age for maximum recovery of haploid plantlets

“…Although haploids were obtained by different researchers following irradiated pollen techniques in kiwifruit (Pandey et. al., 1990;Chalak and Legave, 1997;Musial and Przywara, 1998;1999), apple (Zhang and Lespinasse, 1991;De Witte and Keulemans, 1994;Höfer and Lespinasse, 1996), pear (Bouvier et al, 1993), European plum (Peixe et al, 2000), blackberry (Naess et al, 1998), sweet cherry (Höfer and Grafe, 2003), and Citrus (Froelicher et al, 2007;Aleza et al, 2009;Yahata et al, 2010), the induction mechanism of those haploid plants is not yet clear. It is therefore imperative to ascertain the hybridity of those in vitro-raised plantlets to confirm their genetic origin using a precise system.…”