We sequenced and analyzed the complete chloroplast genome of Aster tataricus (family Asteraceae), a Chinese herb used medicinally to relieve coughs and reduce sputum. The A. tataricus chloroplast genome was 152,992 bp in size, and harbored a pair of inverted repeat regions (IRa and IRb, each 24,850 bp) divided into a large single-copy (LSC, 84,698 bp) and a small single-copy (SSC, 18,250 bp) region. Our annotation revealed that the A. tataricus chloroplast genome contained 115 genes, including 81 protein-coding genes, 4 ribosomal RNA genes, and 30 transfer RNA genes. In addition, 70 simple sequence repeats (SSRs) were detected in the A. tataricus chloroplast genome, including mononucleotides (36), dinucleotides (1), trinucleotides (23), tetranucleotides (1), pentanucleotides (8), and hexanucleotides (1). Comparative chloroplast genome analysis of three Aster species indicated that a higher similarity was preserved in the IR regions than in the LSC and SSC regions, and that the differences in the degree of preservation were slighter between A. tataricus and A. altaicus than between A. tataricus and A. spathulifolius. Phylogenetic analysis revealed that A. tataricus was more closely related to A. altaicus than to A. spathulifolius. Our findings offer valuable information for future research on Aster species identification and selective breeding.
Medicinal and edible seed Semen Persicae is susceptible to mycotoxin and fungal contamination. However, the occurrence of mycotoxin contamination and fungal infection is still unclear. In this paper, ultra-high performance liquid chromatography-tandem triple quadrupole mass spectrometry and high-throughput sequencing were conducted to determine the mycotoxin contents and fungal abundances of Semen Persicae. 42.86% of samples were positive for aflatoxin B1 (26.48–48.37 μg/kg) and 28.57% of samples were positive for aflatoxin B2 (1.47–4.82 μg/kg). Ochratoxin A and fumonisin B1 were only detected in one sample (91.02 and 34.61 μg/kg, respectively). Chao 1 and Shannon indices were significantly higher in the Dalian of Liaoning, Baotou of Innermongolia and Langfang of Hebei regions than in other groups. Ascomycota, Basidiomycota, Wallemia, Candica, Saccharomyces and Aspergillus were the predominant fungi and they were significantly region-specific. Simultaneously, the diversity, composition and co-occurrence network complexity in the mycotoxin-free group were significantly higher than those in the mycotoxin-contaminated group. Spearman correlation analysis showed aflatoxins, ochratoxin A and fumonisins contents were positively and significantly correlated with the abundances of Aspergillus, Rhodotorula, Wallemia and Candida. In conclusion, this study reported the prevalence of mycotoxin contamination and the great diversity of fungi associated with Semen Persicae for the first time, providing an early warning for subsequent potential mycotoxin biosynthesis.
9 July 2020 in Journal of Plant Biochemistry and Biotechnology
The aim of this study was to investigate the fertility of "Huajin 6" and the effect of exogenous methyl jasmonate on its fertility. In this study, "Huajin 6", "Huajin 6" treated with methyl jasmonate and "Damaohua" were used as the research objects, the stamen phenotypes and the shape of pollen grains were observed, pollen viability and stigma receptivity were measured. The results showed that the pistil structure and function were normal, and although the stamen anthers did not dehisce, they were still capable of producing pollen with a certain amount of vigor. Methyl jasmonate could promote the opening of the flowers of "Huajin 6" and improve the development of pollen grains to a certain extent, but it could not promote anthers dehiscence of "Huajin 6". This study can provide theoretical guidance for the cultivation of new honeysuckle varieties using "Huajin 6".