Effect of Growth Regulator, Sucrose, and Minimal-growth Conservation on In Vitro Propagation of Virus-free Sweet Potato Plantlets

Abstract

The influence of growth regulators (NAA and BA) and sucrose concentrations (0, 3, 5, 7, 9%) on in vitro rapid-propagation of virus-free sweet potato [Ipomoea batatas (L.) Lam.] was investigated with single-node or shoot-tip culture of two cultivars ('Matnami' and 'Shinhwangmi'). The survival rate and growth of shoot-tip explant was also investigated under the presence or absence of light (blue and red LED = 7:3, 150±5 μmol•m -2 •s -1 PPFD) during minimal-growth in vitro conservation at 15°C. Vine length, vine diameter, fresh weight and dry weight were enhanced without callusing of explant in the MS medium supplemented with 0.2-0.5 mg•L -1 BA. The growth of single-node and shoot-tip explants were significantly enhanced with the increase of vine length, number of leaf, number of root, fresh weight, and dry weight in the solid medium containing 5% sucrose and 0.2 mg•L -1 BA. Vine elongation of shoot-tip explants were highest in the liquid medium containing 3% sucrose than the solid medium. The survival rate of minimal-growth in vitro conservation was 100% in 5 months under the presence of light (LED, 150±5 μmol•m -2 •s -1 PPFD) at 15°C, but the explants in dark condition died in 3 months. The light was absolutely necessary for the in vitro conservation under minimal-growth conditions of virus-free sweet potato plantlets at 15°C, and the high density of explants (10 plantlets per Petri Dish) was increased the efficiency of mass conservation.

Nerine Latent Virus Diagnosed in Hippeastrum Bulbs in Korea

“…Because the viruses survive in the dormant bulb, they may be transported across long distances via international trade (Pearson et al, 2009). The vegetative means of propagating bulbs favor the accumulation and dissemination of viruses (Wylie and Jones, 2012;Kim et al, 2019;Lee and Lee, 2019). Therefore, amaryllis bulb tissues were used to investigate the contagion of NeLV in this study.…”