Haploid plant production through anther culture in day-neutral

J. ISSAAS Vol. 18, No. 1:173-184 (2012)a0.2 cmcmb1.0 cmcmC1.0 cmde1.5 cm 1.5 cm 0.5 cmfFig. 2. Callus growth response on different auxin/cytokinin combinations two months after culture inday-neutral strawberry cv. ‘Albion’a. control: anther failed to produce callus, bar = 0.2 cm; b. 0.1 mg L -1 BA + 2.0 mg L -1 IAA + 0.4 mgL -1 2,4-D: callus growth response: grey white, soft, watery, and friable; c. 0.1 mg L -1 BA + 0.4 mg L -1IAA + 2.0 mg L -1 2,4-D: callus growth response: brown, soft, and friable; d. 0.4 mg L -1 BA + 0.1 mgL -1 IAA +2.0 mg L -1 2,4-D: callus growth response: compact, white-cream, largest volume; e. 1.0 mgL -1 BA + 1.0 mg L -1 IAA + 0.4 mg L -1 2,4-D: callus growth response: compact and yellow-green; f. 2.0mg L -1 BA + 0.1 mg L -1 IAA + 0.4 mg L -1 2,4-D: callus growth response: soft, watery, brown, smallvolumeNiemirowicz-Szczytt (1990) reported that a combination of 0.4 mg L -1 BA + 0.1 mg L -1 IAA+ 2.0 mg L -1 2,4-D was good for inducing callus in strawberry anther culture and was similar to thisresults. Jiajun and Kai-hua (2008) reported that MS medium supplemented with 2.0 mg L -1 BA + 1.0mg L -1 2,4-D produced higher callus in strawberry cv. ‘Dajiangjun’ than that of cv. Xiangfei. In theother hand, Perera et al. (2009) showed that combination of auxin and cytokinin is more beneficialthan cytokinin alone for callus induction. They stated that kinetin and 2-Isopentyl adenine enhancedthe production of callus when 100 M 2,4-D which was presented in the culture medium for coconutanther culture. In this experiment, the response for callusing reduced as the level of BA increased (≥ 1mg L -1 ) and this finding was similar to those reported by Nehra et al. (1990). In contrast, Quarta et al.(1991) used only 23 M kinetin in both solid and liquid media (GD medium) and received highestcallus induction rate in strawberry anther culture. Markedly, genotypes were reported to play animportant role in callusing response in Gentiana triflora (Doi et al., 2010) and Carum carvi L.(Smýkalová et al., 2009) although anthers were cultured in the same conditions and perhaps as Sajiand Sujatha (1998) said the different callus response could be due to the presence of different level ofendogenous hormones in sunflower anther culture.Effect of plant growth regulator on plant regenerationVarious combinations of BA and IAA had a considerable effect on plant regeneration (Table 2and Fig. 3). Out of seven combinations of hormones, the callus cultured on MS medium containing2.0 mg L -1 IAA and 1.0 mg L -1 BA gave highest shoot regeneration (8.1%) and the number of shootper callus (5.0). In the combination of 1.0 mg L -1 IAA + 0.5 mg L -1 BA, the regeneration frequencyrate and number of shoot per callus were low (3.2%, and 1.1 shoots, respectively). Controversially,callus size increased in the media with 2.0 mg L -1 IAA + 0.5 mg L -1 BA without shoot occurrence (Fig.3f). On the media without hormones (control) or 0.5 mg L -1 IAA + 1.0 mg L -1 BA or 0.5 mg L -1 IAA177