The 2011 ASHS Annual Conference

Ilex glabra (L.) A. Gray (inkberry) has been successfully micropropagated using nodal segments containing one axillary bud. However, genotype variation in tissue culture shoot proliferation and rooting has not been studied. ‘Leucocarpa’, ‘Pretty Boy’, ‘Pretty Girl’, and ‘Shamrock’ inkberry were cultured on MS + 90 mM sucrose using nodal segments with one axillary bud (1-1.5cm). They were proliferated on MS + 4.5 µM ZT and rooted on 1/4 MS plus 10.3 µM IBA. ‘Pretty Boy’ had greatest shoot multiplication averaging 4 shoots per explant while ‘Leucocarpa’, ‘Pretty Girl’, and ‘Shamrock’ produced an average of 2 shoots per explant.  The length of ‘Pretty Boy’ and ‘Leucocarpa’ shoots was 4.5cm, significantly higher than that of ‘Pretty Girl’ (2.5 cm) and ‘Shamrock’ (2.3 cm). ‘Pretty Boy’ microcuttings exhibited a higher rooting percentage (94.5%) compared to the other three cultivars (72.3%).  ‘Pretty Boy’ root quality, in terms of the root ball volume and root rating, was also better than the other three cultivars.   ‘Shamrock’ had a little better rooting ability than ‘Pretty Girl’ and ‘Leucocarpa’.  The white fruit cultivar ‘Leucocarpa’ showed no difference from the cultivars that had black fruits. The results also suggest that gender might have an important effect on the micropropagation, as there was a difference in both shoot multiplication and root formation by ‘Pretty Boy’ (male) and ‘Pretty Girl’ (female). Further studies on the effects of gender on micropropagation of woody ornamental plants should be investigated.