Liobagrus brevispina, a new species of torrent catfish (Siluriformes: Amblycipitidae) from the upper Chang-Jiang basin, South China.

A new species of Liobagrus is unearthed in the Nan-Jiang flowing into the Jialing-Jiang of the upper Chang-Jiang basin in which currently recognized Chinese congeners have a concentrated distribution. This small-sized (less than 100.0 mm LS ) torrent fish belongs to the species group defined by the presence of a smooth posterior edge of the pectoral-fin spine and upper and lower jaws of equal length or a lower jaw slightly longer than the upper jaw in length. It is distinct from Liobagrus aequilabris and Liobagrus formosanus by the presence of a pectoral-fin spine extending short of (vs. beyond) the vertical through the dorsal-fin origin, maxillary barbels reaching the middle of the pectoral fin (vs. pectoral-fin insertion or slightly beyond), 17-19 anal-fin rays (vs. 15-16 in L. formosanus), 39-41 (vs. 35-37 in L. aequilabris) post-Weberian vertebrae and the pectoral-fin spine length 3.6%-7.4% of LS (vs. 7.6-10.5 in L. aequilabris). It differs from Liobagrus marginatoides by the presence of upper and lower jaws of equal length (vs. a lower jaw slightly longer than the upper jaw in length) and a rounded or unevenly rounded (vs. subtruncate) caudal fin. The validity of the new species is confirmed by its monophyly recovered in a cytochrome b gene-based phylogenetic analysis and its significant genetic distance with sampled congeneric species.

Regenerative plantlets with improved agronomic characteristics caused by anther culture of tetraploid potato (Solanum tuberosum L.).

Objective: As the primary means of plant-induced haploid, anther culture is of great significance in quickly obtaining pure lines and significantly shortening the potato breeding cycle. Nevertheless, the methods of anther culture of tetraploid potato were still not well established. Methods: In this study, 16 potato cultivars (lines) were used for anther culture in vitro. The corresponding relation between the different development stages of microspores and the external morphology of buds was investigated. A highly-efficient anther culture system of tetraploid potatoes was established. Results: It was shown in the results that the combined use of 0.5 mg/L 1-Naphthylacetic acid (NAA), 1.0 mg/L 2,4-Dichlorophenoxyacetic acid (2,4-D), and 1.0 mg/L Kinetin (KT) was the ideal choice of hormone pairing for anther callus. Ten of the 16 potato cultivars examined could be induced callus with their respective anthers, and the induction rate ranged from 4.44% to 22.67% using this hormone combination. According to the outcome from the orthogonal design experiments of four kinds of appendages, we found that the medium with sucrose (40 g/L), AgNO3 (30 mg/L), activated carbon (3 g/L), potato extract (200 g/L) had a promotive induction effect on the anther callus. In contrast, adding 1 mg/L Zeatin (ZT) effectively facilitated callus differentiation. Conclusion: Finally, 201 anther culture plantlets were differentiated from 10 potato cultivars. Among these, Qingshu 168 and Ningshu 15 had higher efficiency than anther culture. After identification by flow cytometry and fluorescence in situ hybridization, 10 haploid plantlets (5%), 177 tetraploids (88%), and 14 octoploids (7%) were obtained. Some premium anther-cultured plantlets were further selected by morphological and agronomic comparison. Our findings provide important guidance for potato ploidy breeding.

Re-description of the catfish species Liobagrus kingi Tchang, 1935 (Pisces: Amblycipitidae) from the upper Chang-Jiang basin, China.

The identity and validity of Liobagrus kingi Tchang, 1935 remain contentious to date due to its inaccurate original description. A re-description is provided here for this species based on our examination on its type, hitherto deposited in ASIZB and available topotypic material. It is confirmed that L. kingi is a species with a serrated posterior edge of the pectoral-fin spine and distinct from the sympatrically existing species L. nigricauda. Comments on former recognitions of specimens from the upper Chang-Jiang basin as L. kingi are presented.