Sequence analysis based on ITS1 region of nuclear ribosomal DNA of Amomum villosum and ten species of Alpinia

Ripe fruits of Amomum villosum Lour. are important traditional Chinese medicines and food spices. Due to similar morphological and anatomical characteristics, fruits from some Alpinia species are used clinically as substitutes or adulterants of Fructus Amomi. In this study, we determined the nrDNA ITS1 (internal transcribed space 1) sequences from Amomum villosum and ten Alpinia species, which are adulterants of Fructus Amomi. The ITS1 sequences of these species were 175-179 bp in length, and the G+C contents were 53.37-56.74%. Sequence alignment revealed that there were 55 polymorphic nucleotide sites among the tested species. The base substitution were 0.57-9.60% within the ten Aplinia species, but 17.61-21.59% between Amomum villosum and the Alpinia species. These molecular data indicated that ITS1 sequences can be used to differentiate Fructus Amomi and its substitutes or adulterants from various Alpinia species.