Plant Regeneration from Anther-derived Embryos of Apple and Pear

Abstract

<jats:p>Anthers of six apple [<jats:italic>Malus</jats:italic> ×<jats:italic>domestica</jats:italic> (L.) Borkh.], three Japanese pear (<jats:italic>Pyrus pyrifolia</jats:italic> N.) and two European pear (<jats:italic>Pyrus communis</jats:italic> L.) scion cultivars were cultured. Callus formation occurred from anthers of all cultivars and androgenic embryogenesis was observed from all except <jats:italic>P. pyrifolia</jats:italic> `Kosui' and <jats:italic>P. communis</jats:italic> `La France'. Regeneration of adventitious shoots from anther-derived embryos was shown from all apple cultivars and <jats:italic>P. pyrifolia</jats:italic> `Shinko'. Many of these shoots did not grow or died on half-strength Murashige and Skoog medium (1962) with 4.4 μ<jats:sc>m</jats:sc> BA and 0.5 μ<jats:sc>m</jats:sc> IBA, whereas several shoots of apple `Starking Delicious' grew to plantlets. Chromosome counts of shoot apical cells of four clones derived from embryos of `Starking Delicious' showed that three clones were diploids and one clone comprised diploid and haploid shoots, suggesting that at least one clone originated from a microspore. Chemical names used: 3-indolyl-butyric acid (IBA); N<jats:sup>6</jats:sup>-benzyladenine (BA).</jats:p>

Doubled haploid production in fruit crops

“…In previous anther culture experiments carried out on three Japanese pear cultivars, nine embryos were obtained from cultivar Gold Nijisseiki (at 0.12% rate) and 10 from cv. Shinko (at 0.13% rate), but plant regeneration was not established (Kadota et al, 2002).…”

“…Usually, anther culture media are solidified by adding agar. Other gelling agents can be potato starch Germana`et al, 2000a, unpublished), gelrite , agarose (Kadota et al, 2002;Assani et al, 2003) and gellan gum (Kadota et al, 2002). There are different opinions regarding the use of liquid media rather than solid media.…”

“…Temperatures used for apple anther culture are 23-30°C (Ho¨fer and Lespinasse, 1996;Kadota et al, 2002). In apple anther culture, Ho¨fer and Hanke (1990) obtained better results in the dark, while Fei and Xue (1981) achieved embryo induction under continuous light.…”

“…Two embryos were produced by pear anther culture, cv. Le Lectier, but their origin was not established and plant regeneration was not obtained (Kadota et al, 2002).…”

“…In pear, as well as in apple, regeneration from embryos was obtained after a cold treatment (12 weeks) through rooting of shoots developed from embryos (Kadota et al, 2002). The adventitious shoots lacked vigour and for the most part died.…”