ABSTRACT. Dioscorea opposita Thunb., included in the genus Dioscorea of the family Dioscoreaceae, is an important herb with great edible and medicinal value. In this study, the total RNA from leaves of Lichuan Dioscorea opposita Thunb. was isolated by an improved Trizol method. The results showed that the RNA extracted by the improved Trizol method had good integrity, and the RNA could be used for downstream molecular biology operations including reverse transcriptionpolymerase chain reaction.

ABSTRACT. Dioscorea opposita Thunb. has been used as health food and herbal medicinal ingredients in traditional Chinese medicine. In this study, the total DNA of D. opposita Thunb. was extracted using an improved cetyltrimethylammonium bromide (CTAB) method, and the extracted DNA was further used for random amplified polymorphic DNA (RAPD) reaction system by design of the L 16 (4 4 ) orthogonal diagram. The results showed that the improved CTAB method can be used to isolate high-quality and high-concentration DNA, and the optimized protocol can overcome the instability of RAPD reaction system. The knowledge stated here can be used to study the genetic diversity of D. opposita Thunb.

ABSTRACT. Aloe, an important folk herbal drug, includes abundant polysaccharides and secondary metabolites, which make it difficult to isolate high-quality DNA or RNA. In this paper, one and two improved methods were used to isolate the genomic DNA and RNA from the leaf of aloe, respectively. The obtained samples presented good quality and integrity; thus, they could be further used for many downstream molecular experiments. These reported protocols for DNA and RNA extraction offered a valuable reference for other related studies.