3.4 OTU delineation based on DNA barcodes using ABGD
ABGD software was utilized to delineate 189 morphological species and in
total, 1227 sequences with the assignments for intraspecific divergence
(p) values between 0.001 and 0.100. The results included two cases:
initial partition and recursive
partition. As revealed in Part II (Supporting information), 1227
samples were divided into 227
groups
(p value: 0.0028-0.0077) and 190
groups (p value: 0.0129-0.0599). ABGD analysis of the whole sequencing
data derived a total of 190 OTUs
(Operational taxonomic units) with a prior intraspecific divergence of
Pmax = 0.0599. Therefore, we chose
relatively stable initial results to compare with those of morphological
identification. We found that A. montanus and D. gueriniformed into two different groups, whereas Chironomus s p. XJ andC. heterodentatus , P. bullum and P. laetum ,Diamesa sp. XJC and Diamesa sp. XJB clustered into
the same group, respectively.