Effects of sterilizing agents, phenolic compound inhibitors, and plant hormones in vitro on lateral bud explant culture of three durian varieties

The most effective sterilizing agent for achieving sterility in durian lateral bud explants of ‘Monthong’, ‘Kradum Thong’, and ‘Puangmanee’ durian varieties was a 0.3% mercuric chloride (HgCl2) solution for 10 minutes. This treatment resulted in significantly higher contamination-free survival rates (P < 0.05) by 70%, 60%, and 50%, respectively, compared to the control treatments. The control treatments involved 30% Clorox (sodium hypochlorite, NaOCl) for 15 minutes followed by 5% Clorox for 10 minutes, resulting in 0% survival. The liquid Woody Plant Medium (WPM) supplemented with Polyvinylpyrrolidone (PVP) at a concentration of 1.0 g/L achieved the most effective reduction in mucilage (phenolic compounds), resulting in 100% effectiveness. PVP acts as an antioxidant, contributing to reduced phenolic compound formation. As a result, the lateral bud explant of durian remained green and clean, and the phenolic compound on the cut surface of the explant effectively dissolved. Notably, this result was significantly better (p < 0.05) than using the control liquid medium (WPM). Over 7 months of subculturing on a solid medium once every month, findings revealed a distinct pattern in ‘Monthong’ durian lateral bud explants. When it cultured on WPM supplemented with 1.0 mg TDZ (Thidiazuron)/L and 10% coconut water, these explants exhibited significantly longer green callus lengths than the rest tested solid media. The combination of a low TDZ level (1.0 mg/L) with coconut water in the WPM solid medium appeared to play a crucial role in promoting callus formation. Interestingly, WPM supplemented with 3.0 mg BA (6-Benzyladenine)/L led to lateral bud explants of ‘Kradum Thong’ durian splitting into two shoots, each with leaf growth. Conversely, WPM supplemented with 3.0 mg TDZ/L promoted larger shoots with green leaf color. These findings provided valuable insights into optimizing tissue culture conditions for different durian varieties.