An Efficient Plant Regeneration System for Different Explants of Rare and Endangered Plants in Mussaenda anomala

To establish an efficient regeneration method for the rare and endangered plant Mussaenda anomala to address problems regarding its reproductive obstacles and scarce populations.In this study,the terminal buds,axillary buds,stem segments with two axillary buds,stem segments with two axillary buds and one terminal bud,and leaves of M.anomala were used as explants.The effects of different explants and disinfection methods,plant growth regulators and substrates on plant regeneration were explored.The following results were obtained:(1)The terminal bud was a suitable explant for M.anomala tissue culture,and the disinfection method utilized was treatment with 0.2%HgCl2 for 8 min.(2)Initiate medium:MS basic medium supplemented with 0.5 mg/L 6-BA and 0.2 mg/L IBA for the high germination rate(100%)and the maximum bud height(1.70 cm)of the terminal bud.(3)Proliferation medium:MS basic medium supplemented with 3.0 mg/L 6-BA and 0.2 mg/L IBA for a high proliferation rate(96%)and proliferation time(6.0)of terminal buds.(4)Proliferation medium supplemented with 0.7 mg/L GA3 significantly increased the bud heights of multiple buds.(5)Rooting medium:MS basic medium supplemented with 0.5 mg/L IBA and 0.5 mg/L IAA for a high rooting rate(88%),root number(12.0)and root length(5.07 cm).(6)The optimal substrate for seedling acclimation and transplanting was perlite:vermiculite(1:1),which resulted in the highest survival rate(97%)and plant height(5.89 cm),as well as better growth potential for seedlings.The surfaces of M.anomala explants are densely covered with trichome,which increased the difficulty of disinfection;the plant growth regulators directly affected the growth and development in the regeneration process of M.anomala,and the substrate significantly affected the survival rate and height growth for seedling acclimation.