ANDROGENESIS INDUCTION THROUGH ANTHER CULTURE IN DAY-NEUTRAL STRAWBERRY (FRAGARIA × ANANASSA DUCH) CV. ‘EVEREST’

Abstract

     The anther culture method is commonly applied in inducing androgenesis. Our study was conducted to determine the effects of microspore developmental stage, plant growth regulators (PGRs), and interaction between callus age and medium culture on androgenetic plant production in day-neutral strawberry cv. ‘Everest’. Moreover, simple sequence repeat (SSR) markers were investigated to identify the homozygous regenerants. Anthers containing microspore at uninucleate stage gave the highest response. The most anther-derived calli were obtained on the Dumas De Vaulx medium (C – medium) containing 0.4 mg L^-1 benzyl adenine (BA) + 0.1 mg L^-1 3-indole acetic acid (IAA) + 2.0 mg L^-1 2,4-Dichlorophenoxyacetic acid (2,4-D). The combination of 1 mg L^-1 BA and 2 mg L^-1 IAA produced the maximum rate of plantlet regeneration (10.0%). The interaction between Gamborg medium (B5) and 2- month old callus showed the highest number of shoot regeneration (7.1 shoots). Ploidy analysis of regenerated plants using chromosome observation revealed 50% octoploid (2n = 8x = 56), 10% hexaploid (6x = 42), 35% aneuploid, and 5% haploid (n = 4x = 28). Using 30 SSR primers, we verified the genetic integrity of ten octoploid anther-derived plants with respect to the donor plant. The results showed that no spontaneous doubled haploid originating directly through anther culture was found. This confirmed that all regenerated plants were initiated from somatic cells. Therefore, the in vitro anther culture can provide efficient haploid and micro propagation techniques for day-neutral strawberry.