Genetic relationships among loquat cultivars and some wild species of the genus Eriobotrya based on the internal transcribed spacer (ITS) sequences

The phylogenetic relationships among seven wild species and 25 loquat cultivars of genus Eriobotrya were studied by comparing sequences of the internal transcribed spacer (ITS) region. The length of ITS1 region of Eriobotrya was 223 bp and the lengths of ITS2 were ranged from 201 bp to 203 bp. The G + C contents varied from 64.1% to 65.5% in ITS1 and from 68.5% to 72.1% in ITS2. The aligned sequences were analyzed by neighbor-joining (NJ) and maximum parsimony (MP) methods. The ITS1 spacer region comprised 223 characters, of which 44 were variable sites and 34 were parsimony informative sites. The NJ tree had very similar topology to the MP tree. E. malipoensis and E. seguinii had only one different character in ITS2 region and both of them could be the most primitive species of Eriobotrya genus. ITS2 evolved much faster and had more parsimony informative sites than ITS1. ITS2 presented much more precise information about the phylogenetic relationships. Based on ITS2 regions, the evolution order of the studied taxa in this paper could be concluded, which was E. bengalensis f. angustifolia, E. prinoides var. dadunensis, E. prinoides (E. bengalensis), E. dayaoshanensis and E. japonica Lindl.

► ITS2 presents much more precise information than ITS1.
► Moderate positive correlation is scored (r = 0.712) between ITS1 and ITS2 sequences.
► E. prinoide and E. bengalensis have exactly the same ITS sequence.
► E. malipoensis and E. seguinii have only one different site in ITS region.
► E. prinoides var. dadunensis is one of the ancestors of E. japonica Lindl.