Varietal differences in green plant regeneration ability of wheat pollen embryoids.

Abstract

The present study was undertaken in order to clarify the effect of the culture media and the genotypes on the regeneration of green plantlets from pollen embryoids by anther culture of Japanese wheat cultivars. Pollen embryoids of 4 cultivars produced on Potato-2 medium were transferred onto two kinds of regeneration media (Table 1). On both media, embryoids grew into calli and then regenerated green or albino shoots and/or roots (Fig. 1 b and c). In rare cases, embryoids germinated (Fig. 1 a). The frequencies of green plantlets regenerated from embryoids differed with their genotypes even in the regeneration medium from 2.8% in Nanbukomugi to 33.5% in Chinese Spring. Moreover, the ability of embryoids to regenerate green plantlets was not affected by anther culture media, Potato-2 and C1 medium (Table 2). The effects of abscisic acid (ABA) on the embryoid formation and green plantlet regeneration were studied in anther culture of 7 cultivars (Table 3). ABA at a low concentration (0.1 and 0.5mg/l) had a stimulatory effect on the embryo formation in some cultivars which were genotypes of a rather low ability in embryoid formation, while ABA had a suppressive effect in other cultivars. However, ABA did not show a stimulatory effect on the regeneration of green plantlets in all cultivars tested. In conclusion, the ability of the green plantlet regeneration depended on genotypes regardless of the anther culture and regeneration media tested in this study: Norin 12 and Chinese Spring showed relatively high frequency of the green plantlet regeneration, while Hachimankornugi, Kitakarnikornugi and Norin 61 did not regenerate green plantlets. On chromosome constitutions of the regenerated green plants almost 659 were haploid (2n=21) and about 35% were diploid (2n=42) (Table 4, Fig. 2).