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The species belonging to the Rhododendron genus are well-known for their colorful corolla. Molecular marker systems have the potential to elucidate genetic diversity as well as to assess genetic fidelity in rhododendrons. In the present study, the reverse transcription domains of long terminal repeat retrotransposons were cloned from rhododendrons and used to develop an inter-retrotransposon amplified polymorphism (IRAP) marker system. Subsequently, 198 polymorphic loci were generated from the IRAP and inter-simple sequence repeat (ISSR) markers, of which 119 were derived from the IRAP markers. It was shown that in rhododendrons, IRAP markers were superior to the ISSRs in some polymorphic parameters, such as the average number of polymorphic loci (14.88 versus 13.17). The combination of the IRAP and ISSR systems was more discriminative for detecting 46 rhododendron accessions than each of the systems on their own. Furthermore, IRAP markers demonstrated more efficiency in genetic fidelity detection of in-vitro-grown R. bailiense Y.P.Ma, C.Q.Zhang and D.F.Chamb, an endangered species recently recorded in Guizhzhou Province, China. The available evidence revealed the distinct properties of IRAP and ISSR markers in the rhododendron-associated applications, and highlighted the availability of highly informative ISSR and IRAP markers in the evaluation of genetic diversity and genetic fidelity of rhododendrons, which may facilitate preservation and genetic breeding of rhododendron plants. [ABSTRACT FROM AUTHOR]

An improved photocatalytic microfiltration membrane was successfully prepared by the impregnation method with nitrogen-doped TiO2/graphene oxide (GO) (NTG). By utilizing the unique role of N and GO, the photocatalytic activity of the membrane in UV and sunlight was improved. Compared with the Polyvinylidene Fluoride (PVDF) microfiltration membrane which was modified by TiO2, N-TiO2 (NT) and TiO2-GO (TG), the NTG/PVDF membrane exhibited high photocatalytic efficiency and significantly improved photodegradation power to the methylene blue (MB) solution under ultraviolet light and sunlight, with the photocatalytic efficiency reaching 86.5% and 80.6%, respectively. Scanning electron microscopy (SEM), X-ray diffractometry (XRD) and Fourier transform infrared spectroscopy (FT-IR) were used to analyze the morphology, crystal structure and chemical bonds of the membrane surface. The hydrophilicity of the modified PVDF microfiltration membrane was significantly improved, the flux of the pure water membrane reached 1672 Lm−2h−1, the flux of the MB solution was also significantly improved due to photodegradation. Therefore, the nitrogen-doped titanium dioxide graphene oxide PVDF microfiltration membrane (NTG/PVDF membrane) has great development prospects in sustainable water treatment. [ABSTRACT FROM AUTHOR]