Shallot haploid breeding for sustainable production-callus induction from shallot anther tissues

Shallot is an essential vegetable crop in Indonesia, and its cultivation requires labor and capital intensive. Availability of high yielding and disease resistant shallot varieties will ensure its sustainable production. Haploid breeding should be beneficial for supporting the shallot breeding program. This study aims to identify suitable media for inducing callus growth and subsequent shoots or somatic embryo (SE) regeneration from anther tissues. In this study, successful callus induction was obtained from shallot anther but not for shoots or SE regeneration. The three different flower-sized responses were also investigated, and large flowers (5mm x 3mm) with an average anther length of 1.44 ± 0.04 mm were the best for callus induction. The microscopic observation indicated that large and medium flowers contain most bicellular pollen developmental stages, while small flowers are mostly tetrad stage. It also showed that the bicellular stage was more responsive to callus induction than the tetrad one. Moreover, the C1 medium consisted of MS basal medium supplemented with 3 mg L −1 BAP, 3 mg L −1 NAA, and 30 g/L sucrose was the best medium for inducing callus from anther explant.