Isolation and characterization of the native entomopathogenic nematode, Heterorhabditis brevicaudis, and its symbiotic bacteria from Taiwan.
The occurrence of Heterorhabditis brevicaudis (Rhabditida: Heterorhabditidae) and its symbiotic bacteria, Photorhabdus luminescens subsp. akhurstii in Taiwan were recorded for the first time. H. brevicaudis was described by Liu in 1994, but it was unavailable and no molecular data has ever been published for it ever since. The native entomopathogenic nematode (EPN), H. brevicaudis TG01 was recovered from sandy coastal soils in moist bamboo forest, as observed in this article. The bacterial symbiont was isolated from H. brevicaudis for the first time. On the basis of biochemical tests and 16S rDNA it was identified as P. luminescens subsp. akhurstii. This is also the first report of novel nucleotide sequences of the internal transcribed spacer (ITS) from H. brevicaudis. The phylogenetic relationships of ITS sequences were established using Neighbor-Joining, Maximum Parsimony, and Maximum Likelihood methods. The inferred trees strongly support that H. brevicaudis TG01 is specifically related to H. indica and H. hawaiiensis. But the tail length of the infective juveniles (IJ) of H. brevicaudis TG01 in our study, which was less than 80 microm, shorter than that of other species indeed, fall within the original description for H. brevicaudis. Moreover, comparing with morphometrics of IJ and male of H. brevicaudis and H. indica, we recognize that the H. brevicaudis TG01 does not represent variation among populations of H. indica and H. hawaiiensis. This article will answer questions regarding the status of H. brevicaudis and would also provide this species for further investigation.
Hsieh
Feng-Chia
FC
Biopesticides Division, Taiwan Agricultural Chemicals and Toxic Substances Research Institute, Council of Agriculture, Taichung 41358, Taiwan. hsiehf@tactri.gov.tw
Tzeng
Chiaw-Yen
CY
Tseng
Jui-Tang
JT
Tsai
Yeong-Sheng
YS
Meng
Menghsiao
M
Kao
Suey-Sheng
SS
D000818:Animals; D005260:Female; D008297:Male; D008969:Molecular Sequence Data; D020637:Photorhabdus / Q000145:classification / Q000235:genetics / Q000302:isolation & purification* / Q000502:physiology; D010802:Phylogeny; D017172:Rhabditoidea / Q000145:classification / Q000302:isolation & purification* / Q000382:microbiology* / Q000502:physiology; D012987:Soil / Q000469:parasitology*; D013559:Symbiosis; D013624:Taiwan
D012987:Soil