Water chestnut (Trapa natans L.) is a group of annual, floating-leaved aquatic plants that serves as food and medical resources in many countries. However, the molecular method for distinguishing different T. natans L. resources is lacking. In this study, we detected genetic diversity of several chloroplast and nuclear genic or intergenic sequences in four varieties of T. natans and one wild type of Trapa incisa Siebold & Zuccarini to evaluate their potential as molecular markers. Our data revealed that the three chloroplast fragments (rbcL, matK, and pbsA-trnH) show no sequence difference among all tested samples. Only one nucleotide substitution is detected for the nuclear ribosomal internal transcribed spacer (ITS) in the T. natans variety Shuihongling. Four nucleotide substitutions are detected for the nuclear carotenoid isomerase (CRTISO) gene in the variety Hongxiuxie. In contrast, a total of 29 polymorphic sites are detected for a Toll and interleukin-1 receptor-nucleotide binding site–leucine rich repeat (TNL) gene in the five samples, among which six are nucleotide substitutions and the rest are insertions/deletions. The five samples could be fully distinguished from each other based on the TNL gene. To specifically authenticate ‘Heshangling’, 33 randomly amplified polymorphic DNA (RAPD) markers were adopted to amplify genomic sequences from the five samples. A pair of sequence characterized amplified region (SCAR) primers were designed based on the results of RAPD markers, which could specifically amplify one target band from all eight individuals of ‘Heshangling’, but none from any individuals of other T. natans varieties or one T. incisa. Taken together, a TNL sequence was provided in this study to distinguish four T. natans varieties and one T. incisa. Furthermore, a RAPD-SCAR marker was developed for efficient authentication of ‘Heshangling’.
Yanmei Zhang, Xuelin Shen, Xiaoqin Sun, Jia Liu, Yifeng Xia, Xin Zou and Yueyu Hang
Li-Qiang Tan, Xin-Yu Wang, Hui Li, Guan-Qun Liu, Yao Zou, Shen-Xiang Chen, Ping-Wu Li and Qian Tang
Landrace tea populations are important recourses for germplasm conservation and selection of elite tea clone cultivars. To understand their genetic diversity and use them effectively for breeding, two traditional landrace tea populations, Beichuan Taizicha (BCTZ) and Nanjiang Dayecha (NJDY), localized to northern Sichuan, were evaluated for morphological characters, simple sequence repeat (SSR)–based DNA markers and the contents of biochemical components. A wide range of morphological variation and a moderately high level of DNA polymorphism were observed from both BCTZ and NJDY. NJDY had on average, bigger leaves, larger flowers, higher total catechins (TCs), and greater gene diversity (GD) than BCTZ. Interestingly, samples from BCTZ had a wide range in the ratio of galloylated catechins to nongalloylated catechins (G/NG) (1.83–8.12, cv = 48.8%), whereas samples from NJDY were more variable in total amino acid (TAA) content (25.3–50.8 mg·g−1 dry weight) than those from BCTZ. We concluded that the two Camellia sinensis landrace populations are of great interest for both individual selection breeding and scientific studies.