observation-quantification-mating-behavior-pinewood-nematode

Observation and Quantification of Mating Behavior in the Pinewood Nematode, <em>Bursaphelenchus xylophilus</em>

A method for observing and quantifying the mating behavior of the pinewood nematode, Bursaphelenchus xylophilus, was established under a stereomicroscope. ...

application-rna-interference-pinewood-nematode-bursaphelenchus

Application of RNA Interference in the Pinewood Nematode, <em>Bursaphelenchus xylophilus</em>

The pinewood nematode, Bursaphelenchus xylophilus, is one of the most destructive invasive species worldwide, causing the wilting and eventual death of ...

Zhejiang agricultural & forestry University

Nanjing Forestry University

To understand the efficacy of emamectin benzoate, avermectin, milbemectin, and thiacloprid on the reproduction and development of Bursaphelenchus xylophilus, seven parameters, namely population growth, fecundity, egg hatchability, larval lethality, percent larval development, body size, and sexual ratio, were investigated using sublethal (LC20) doses of these compounds in the laboratory. Emamectin benzoate treatment led to a significant suppression in population size, brood size, and percent larval development with 411, 3.50, and 49.63%, respectively, compared to 20850, 24.33, and 61.43% for the negative control. The embryonic and larval lethality increased obviously from 12.47% and 13.70% to 51.37% and 75.30%, respectively. In addition, the body length was also significantly reduced for both males and females in the emamectin benzoate treatment. Avermectin and milbemectin were also effective in suppressing population growth by increasing larval lethality and reducing larval development, although they did not affect either brood size or embryonic lethality. Body length for both male and female worms was increased by avermectin. Thiacloprid caused no adverse reproductive effects, although it suppressed larval development. Sexual ratio was not affected by any of these four nematicides. Our results indicate that emamectin benzoate, milbemectin, and avermectin are effective against the reproduction of B. xylophilus. We think these three nematicides can be useful for the control of pine wilt disease.

Efficacy of Four Nematicides Against the Reproduction and Development of Pinewood Nematode, Bursaphelenchus xylophilus.

Bursaphelenchus xylophilus is one of the most destructive invasive species, causing extensive economic losses worldwide. The sex ratio of female to male of B. xylophilus plays an important role in the nematode infestation. However, little is known about the processes of its sex determination. The double sex/mab-3-related family of transcription factors are highly conserved in animals, playing crucial roles in sex determination, spermatogenesis and ontogenesis. We therefore investigated its orthologue, Bxy-mab-3, in B. xylophilus.

The role of mab-3 in spermatogenesis and ontogenesis of pinewood nematode, Bursaphelenchus xylophilus.

Bursaphelenchus xylophilus is an invasive plant-parasitic nematode causing the notorious pine wilt disease (PWD) worldwide, which results in huge economic losses. G protein-coupled receptors (GPCRs) play an essential role in mating and reproduction behavior of animals. As a unique biogenic amine in invertebrates, octopamine (OA) can regulate a variety of physiological and behavioral responses by binding specific GPCRs. These specific GPCRs are also called octopamine receptors (OARs), and octr-1 is one of them. However, Bxy-octr-1 is unknown in B. xylophilus. Therefore, we investigated the expression pattern and biological function of Bxy-octr-1. Bioinformatics analysis indicated that Bxy-octr-1 was evolutionarily conserved. The real-time quantitative PCR data revealed that Bxy-octr-1 expression was required throughout the entire life of B. xylophilus. mRNA in situ hybridization showed that Bxy-octr-1 was mainly located in the cephalopharynx, body wall muscle, intestine, and gonadal organs of B. xylophilus. RNA interference (RNAi) showed that embryo hatching rates and locomotion speeds were both dramatically decreased. Obvious abnormal phenotypes were observed in the second-stage of juveniles after RNAi treated. Furthermore, its ontogenesis was stunting. Lack of Bxy-octr-1 reduced fecundity of females, of which 31.25% of them could not successfully ovulate. In addition, the error positioning ratio of the nematode was significantly increased. Our study suggests that Bxy-octr-1 is indispensable for locomotion, early ontogenesis and mating behavior in B. xylophilus.

Jiafu Hu

Department of Forest Protection,
College of Forestry and Biotechnology

Zhejiang agricultural & forestry University

Observation and Quantification of Mating Behavior in the Pinewood Nematode, Bursaphelenchus xylophilus

Application of RNA Interference in the Pinewood Nematode, Bursaphelenchus xylophilus

Jiafu Hu

Department of Forest Protection,College of Forestry and Biotechnology

Zhejiang agricultural & forestry University

Observation and Quantification of Mating Behavior in the Pinewood Nematode, Bursaphelenchus xylophilus

Application of RNA Interference in the Pinewood Nematode, Bursaphelenchus xylophilus

Department of Forest Protection,
College of Forestry and Biotechnology