Views: 5 Author: Cao Shuqin, Wang Xianghua, Qin Weiqiang, Wu Fang, Liu Tiezhi, Tuli Guer, Li Shuanglong, Chen Zuohong, Liu Dongmei Publish Time: 2023-02-14 Origin: 菌物学报
Lactarius acerrimus, the only milk cap with 2-spored basidia known, has been reported from China for several times. Examination on the voucher specimens, however, did not approve the presence of this species in China. Instead, we found a new species L. liyuanus, a close relative of L. acerrimus. It is recognized by the yellowish brown zonate pileus with hairy margin, scrobiculate stipe, white and unchanging latex and spores with high and acute ridges. It is easily distinguished from L. acerrimus by the 4-spored basidia and smaller spores with higher ridges. DNA barcode ITS sequences, additional multi-gene data and detailed morphological description are presented. Re-identification of the Chinese voucher specimens of L. acerrimus is given.
Fig. 1 Original tree generated by neighbor-joining (NJ) analysis of Lactarius liyuanus and its look-alikes based on ITS sequences, rooted with L. lignyotus and L. oomsisiensis. NJ bootstrap higher than 70% are indicated above or by the branches except for the 47% value for the big clade formed by the 35 specimens sequenced. Sample names are presented in the order of species name, voucher specimen, GenBank accession, and the geographical origin. For the 35 studied specimens, all were collected from China and the province names are given.
Fig. 2 Lactarius liyuanus (XHW2936, holotype). A: Basidiocarps. B: Basidiospores. C: Pleuromacrocystidia. D: Cheilomacrocystidia. E: Pileipellis.
Fig. 3 Lactarius liyuanus and its morphologically similar taxa. A: T2181705 from Jilin (clade I). B: WQQ-L142 from Hunan (clade II). C: L. liyuanus, ZLY6912 from Yunnan. D: L. mediterraneensis, XHW5749 from Tibet. E: L. cf. wenquanensis, XHW5854 from Yunnan. F: L. indozonarius, ZLY6905 from Yunnan.
Fig. 4 Spore dimensions of Lactarius liyuanus and its morphologically similar taxa. Each symbol represents the average length and width of 20 spores from one basidiocarp. Clades I-IV correspond to the four clades in Fig. 1.
