How to Choose the Right Disinfectant to Grow Sweet Potatoes in the Lab?

Growing sweet potatoes in vitro isn’t a simple hobby: you need a flawless sterilisation protocol, the right explant age, and a suitable variety. A recent study tested two disinfectants – sodium hypochlorite and mercuric chloride – on three genotypes (Nakabo, Boyapleu, and Irene) and on nodal explants aged 2, 3, and 4 weeks. The findings? A 10% sodium hypochlorite solution dramatically cut contamination, achieving 75.7% clean cultures and 86.8% regeneration, regardless of explant age. In contrast, mercuric chloride, especially at higher concentrations, caused necrosis and killed the tissue. Among the ages, 3‑week‑old explants performed best, with 93.8% clean cultures and 54.9% regeneration. Regarding genotypes, Boyapleu and Irene proved more robust, while Nakabo struggled. In short, for healthy in‑vitro sweet potatoes, use 10% hypochlorite, take explants at three weeks, and choose varieties like Boyapleu or Irene.

Sodium hypochlorite (NaOCl) works as an oxidising agent, denaturing microbial proteins and disrupting cell membranes. At about 10% (v/v) it balances disinfection efficacy with plant tissue toxicity. Mercuric chloride (HgCl₂) is an alkylating agent that binds to –SH groups in proteins, but its high reactivity also damages plant cells, causing necrosis and loss of viability. Genotypic response varies with cuticle composition and phenolic content: varieties like Boyapleu and Irene have thicker cuticles and higher antioxidant enzyme activity (peroxidase, catalase), mitigating oxidative stress from the disinfectant. Nakabo, conversely, has a thinner cuticle and lower antioxidant levels, making it more vulnerable. Explant age affects the density of active meristematic cells: at three weeks the meristem is sufficiently developed for regeneration yet still young enough to tolerate treatment shock. Additionally, culture medium composition (macronutrients, micronutrients, sugars, hormones such as BAP and NAA) can modulate regenerative response, promoting callus formation and subsequent organogenesis. An integrated approach combining optimal disinfectant, explant age, and genotype selection is therefore essential to maximise sweet potato micropropagation efficiency.