Endosperm-derived triploid plant regeneration in diploid Actinidia kolomikta , a cold-hardy kiwifruit relative

Effect of medium composition, genotype and age of explant on the regeneration of hexaploid plants from endosperm culture of tetraploid kiwiberry (Actinidia arguta)

“…ZEA, the first naturally occurring cytokinin to be identified, has been widely used in studies on plant tissue culture, and has already proven its organogenic potential in the genus Actinidia, in terms of adventitious shoot bud induction and elongation from callus cultures (Mu et al 1990;Liu et al 1998;Takahashi et al 2004;Lan et al 2007). In A. kolomikta, shoot elongation was obtained only when an endosperm-derived callus with adventitious shoot primordia were cultured on ZEA (Asakura and Hoshino 2017). The successful use of ZEA for shoot regeneration was reported for Actinidia tissue after transformation or cryopreservation treatments (Wang et al 2006;Mathew et al 2018;Mathew et al 2019;Herath et al 2020;Pathirana et al 2021).…”

“…Regarding rooting, the micro-cuttings of A. arguta responded positively to different RIMs, though very minimal callus formation at the basal end of the stems occurred on a medium supplemented with IAA. On the contrary, robust rooting of micro-cuttings in A. deliciosa (Góralski et al 2005) and A. kolomikta (Asakura and Hoshino 2017) was obtained on a half-strength-MS medium that was free of PGRs. The role of auxins, in turn, is well established in in vitro rooting of micro-cuttings and those hormones are widely used in plant species known to be recalcitrant to rooting (Fogaca and Fett-Neto 2005).…”

“…The method has been used to confirm the endosperm origin of regenerated plants, for example, of A. chinensis var. deliciosa (Góralski et al 2005), Gomortega keule (Muñoz-Concha 2016), A. kolomikta (Asakura and Hoshino 2017), Melia azedazach (Thang et al 2018), and Passiflora cincinnata (Silva et al 2020). For Actinidia, the range of DNA content of 2C nucleus for tetraploids was reported as 2.83-3.15 pg (an average 2.96 pg) (Start et al 2007).…”

“…(Machno and Przywara 1997), A. chinensis var. deliciosa (Góralski et al 2005;Chłosta et al 2021), and A. kolomikta (Asakura and Hoshino 2017). However, Machno and Przywara (1997) found that during the culturing of endosperm-derived callus of A. arguta (the name of the cultivar not provided), only roots and a few abnormal shoots were formed and no normal regenerants suitable for further breeding developed.…”

Interspecific Hybridization Using Miyama Matatabi (<i>Actinidia kolomikta</i>), a Japanese Indigenous Wild Kiwifruit Relative

“…This species has several desirable characteristics such as a compact showed that A. kolomikta was an important and diverse genetic resource (Asakura and Hoshino, 2016). We also reported that endosperm culture could be used to produce a triploid plant regeneration system (Asakura and Hoshino, 2017a), and that immature seeds from A. kolomikta could be used to create an efficient plant regeneration system (Asakura and Hoshino, 2017b) that may be applicable in future breeding programs for this species.…”