[Complete chloroplast genome of Ligustrum lucidum and highly variable marker identification for Ligustrum].

Ligustri Lucidi Fructus, the sun-dried mature fruit of Ligustrum lucidum, is cool, plain, sweet, and bitter, which can be used as both food and medicine, with the effects of improving vision, blacking hair, and tonifying liver and kidney. It takes effect slowly. However, little is known about the genetic information of the medicinal plant and it is still a challenge to distinguish Ligustrum species. In this study, the complete chloroplast genome of L. lucidum was obtained by genome skimming and then compared with that of five other Ligustrum species, which had been reported. This study aims to evaluate the interspecific variation of chloroplast genome within the genus and develop molecular markers for species identification of the genus. The result showed that the chloroplast genome of L. lucidum was 162 162 bp with a circular quadripartite structure of two single-copy regions separated by a pair of inverted repeats. The Ligustrum chloroplast genomes were conserved with small interspecific difference. Comparative analysis of six Ligustrum chloroplast genomes revealed three variable regions(rbcL-accD, ycf1a, and ycf1b), and ycf1a and ycf1b can be used as the species-specific DNA barcode for Ligustrum. Phylogeny analysis provided the best resolution of Ligustrum and supported that L. lucidum was sister to L. gracile. This study clarified the genetic diversity of L. lucidum from provenance, which can serve as a reference for further analysis of pharmacological differences and breeding of excellent varieties with stable drug effects.

[Spectroscopic Studies on the Host Plant Selection Mechanism of Trabala vishnou gigantina Yang (Lepidoptera: Lasiocampidae)].

Trabala vishnou gigantina Yang (Lepidoptera: Lasiocampidae) is a polyphagous forestry pest whose periodic breaking out results in great economic damage including total crop failure to forestry and fruit production in China. In this study, in order to improve the understanding of the host plant selection mechanism of T. vishnou gigantina larvae, locust, caragana, willow, poplar, apricot and sea-buckthorn were used as potential host plants for the test. Two-way choice experiment method was used to study the T. vishnou gigantina Yang feeding preferences of the six kinds of plants. Moreover, the chemical component and physical structure of six plants were analyzed with Fourier transform infrared (FTIR) spectroscopy and X-ray diffraction (XRD). Among the six plants, T. vishnou gigantina larvae showed a strong preference for sea-buckthorn, followed by, apricot, willow, poplar, locust, and caragana. The FTIR analysis displayed that those six plants presented similar characteristic on absorption peak position, peak amount, and shape. The targets (1 154/1 733, 1 154/898) by FTIR showed that lipids and polysaccharide were major nutriments to affect the host plant selection of T. vishnou gigantina larvae. The XRD results showed that crystallinity index (CrI) also could affect the host plant selection of T. vishnou gigantina larvae. In this research, spectroscopy technology was firstly applied to the study of interactive relationship between insect and host, which would blaze a trail for intensive study of host plant selection mechanism of insect at molecular level.

Effect of Four Types of Chemical Pretreatment on Enzymatic Hydrolysis by SEM, XRD and FTIR Analysis.

Catalpa sawdust was respectively pretreated by NaOH, Ca(OH)2, H2SO4 and HCl solution, and the enzymatic hydrolysis of catalpa sawdust was significantly enhanced by alkaline pretreatments. In order to investigate the mechanisms of pretreatment of catalpa sawdust, the characteristics of catalpa sawdust before and after pretreatments were analyzed by scanning electron microscopy (SEM), X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy. It was found that the surface of catalpa sawdust was disrupted by four kinds of chemical pretreatment, and the pretreatment with Ca(OH)2 solution resulted in the most serious damage. The XRD results showed that part of amorphous regions was damaged by alkaline pretreatments, which led to a relative increase of crystallinity Index (CrI) of catalpa sawdust; while the CrI of catalpa sawdust was insignificantly influenced by acid pretreatments. The FTIR analysis displayed that the molecular structures of hemicellulose and lignin of catalpa sawdust were damaged in different degrees by four types of pretreatment. The significant improvement of enzymatic hydrolysis of catalpa sawdust after alkaline pretreatment might be attributed to the effective delignification of alkaline.