Abstract
To select cultivars to produce doubled haploids (DHs) efficiently in an anther culture, a total of 28 apple cultivars (25 cultivars and 3 rootstock cultivars) were investigated to assess their callus formation rate, embryo formation rate, shoot formation rate from embryo, and efficiency of shoot multiplication and acclimatization. The callus formation rates of ‘Red Astrachan’, ‘Kinsei’, ‘Tsugaru’, ‘Golden Delicious’ (‘GD’), ‘American Summer Pearmain’ (‘ASP’), ‘Gala’, ‘Rome Beauty’, and ‘Jonathan’ were high, but ‘JM2’ and ‘King of Tompkins’ formed no callus. Regarding the embryo formation rates, ‘ASP’, ‘Rome Beauty’, ‘M.9’, and ‘Starking Delicious’ (‘SD’) were high, but ‘GD’, ‘JM2’, ‘King of Tompkins’, ‘Ralls Janet’, and ‘Smith’s Cider’ formed no embryo. Regarding the shoot formation rate from embryos, ‘Senshu’, ‘Tsugaru’, and ‘Sansa’ showed high values, but ‘Fuji’, ‘Jonathan’, and ‘Wijcik’ did not form shoots at all. The rate of shoot formation from anthers showed a high–low order of ‘Senshu’, ‘SD’, ‘ASP’, and ‘Tsugaru’. Multiplication and acclimatization of the shoots were not easy. Many individuals died. Eventually, only ‘Senshu’ and ‘SD’ acclimatized. Therefore, cultivars that produced DHs efficiently were ‘Senshu’ and ‘SD’. The results indicated that all processes of “embryo formation”, “shoot induction”, and “shoot multiplication and acclimatization” are important for obtaining DHs in apple anther cultures.
