Ảnh hưởng của dịch nghiền hữu cơ đến cảm ứng tạo chồi và khả năng thay thế agar bằng một số vật liệu vô cơ ở giai đoạn tạo rễ của cây cúc cổ Sơn La (Chrysanthemum sp.)

Abstract

Son La heirloom chrysanthemum (Chrysanthemum sp.) is a woody ornamental plant with a bushy growth habit, possessing high ornamental and economic value, and is suitable for pot cultivation and bonsai shaping. However, conventional propagation methods for this cultivar are limited in terms of multiplication rate and plantlet quality. This study aimed to induce in vitro shoot proliferation and rooting of Son La heirloom chrysanthemum and to evaluate the potential replacement of agar with several inorganic materials during the rooting stage. The experiment was conducted on Murashige and Skoog (MS) medium supplemented with 30 g/L sucrose through two stages. In the shoot proliferation stage, stem segments were cultured on MS medium solidified with 8 g/L agar under four treatments: 6-benzylaminopurine (BAP) at 1.5 mg/L, potato extract 10% (w/v), carrot extract 10% (w/v), and coconut water 10% (v/v). After 42 days of culture, the medium supplemented with BAP at 1.5 mg/L produced the highest number of shoots and leaves (5.01 shoots per explant and 33.3 leaves per explant), whereas coconut water at 10% significantly enhanced shoot height (4.62 cm). In the rooting stage, in vitro stem segments were cultured on agar 8 g/L (control) and on inorganic substrates including red lava, black lava, masato, and perlite (30 g per vessel combined with 30 mL liquid MS medium supplemented with 1 mg/L IBA). After 42 days, perlite achieved a rooting percentage of 93%, comparable to agar, while producing significantly longer roots (8.45 cm). Overall, perlite shows strong potential as an alternative to agar in the in vitro rooting stage of Son La heirloom chrysanthemum, contributing to improved plantlet quality for production purposes.