A rapid method for sex identification in Cannabis sativa using High Resolution Melt (HRM) analysis.

We report the identification of two SNPs in Cannabis sativa that are associated with female and male plant sex phenotypes, and are located on the top arm of the X chromosome. High Resolution Melt analysis was used to develop and validate a novel, rapid method for sex identification in medical/recreational cannabis as well as in hemp. This method can distinguish between dioecious male (XY) and dioecious female (XX) cannabis plants with 100% accuracy, and can also be used to differentiate between male and female Humulus lupulus (hop) plants.

Biological Activity of Essential Oils of Four Juniper Species and Their Potential as Biopesticides

The objective of this study was to assess the biological activity of essential oils (EOs) of four Juniperus species obtained via two different distillation methods and their potential as biopesticides. The studied factors were juniper species (Juniperus communis L., J. oxyсedrus L., J. pygmaea C. Koch., and J. sibirica Burgsd), plant sex (male (M) and female (F)), and distillation method (hydrodistillation via a standard Clevenger apparatus (ClevA) and semi-commercial (SCom) steam distillation). The hypothesis was that the EO will have differential antioxidant, antimicrobial, and insecticidal activities as a function of plant species, plant sex, and distillation method. The two distillation methods resulted in similar EO composition within a given species. However, there were differences in the EO content (yield) due to the sex of the plant, and also differences in the proportions of some EO components. The concentration of α-pinene, β-caryophyllene, δ-cadinene and δ-cadinol was dissimilar between the EO of M and F plants within all four species. Additionally, M and F plants of J. pygmaea, and J. sibirica had significantly different concentrations of sabinene within the respective species. The EOs obtained via ClevA extraction showed higher antioxidant capacity within a species compared with those from SCom extraction. All of the tested EOs had significant repellent and insecticidal activity against the two aphid species Rhopalosiphum padi (bird cherry-oat aphid) and Sitobion avenae (English grain aphid) at concentrations of the EO in the solution of 1%, 2.5%, and 5%. The tested EOs demonstrated moderate activity against selected pathogens Fusarium spp., Botrytis cinerea, Colletotrichum spp., Rhizoctonia solani and Cylindrocarpon pauciseptatum. The results demonstrate that the standard ClevA would provide comparable EO content and composition in comparison with SCom steam distillation; however, even slight differences in the EO composition may translate into differential bioactivity.

The Diversity of Plant Sex Chromosomes Highlighted through Advances in Genome Sequencing

For centuries, scientists have been intrigued by the origin of dioecy in plants, characterizing sex-specific development, uncovering cytological differences between the sexes, and developing theoretical models. Through the invention and continued improvements in genomic technologies, we have truly begun to unlock the genetic basis of dioecy in many species. Here we broadly review the advances in research on dioecy and sex chromosomes. We start by first discussing the early works that built the foundation for current studies and the advances in genome sequencing that have facilitated more-recent findings. We next discuss the analyses of sex chromosomes and sex-determination genes uncovered by genome sequencing. We synthesize these results to find some patterns are emerging, such as the role of duplications, the involvement of hormones in sex-determination, and support for the two-locus model for the origin of dioecy. Though across systems, there are also many novel insights into how sex chromosomes evolve, including different sex-determining genes and routes to suppressed recombination. We propose the future of research in plant sex chromosomes should involve interdisciplinary approaches, combining cutting-edge technologies with the classics to unravel the patterns that can be found across the hundreds of independent origins.

The diversity of plant sex chromosomes highlighted through advances in genome sequencing

For centuries scientists have been intrigued by the origin of dioecy in plants, characterizing sex-specific development, uncovering cytological differences between the sexes, and developing theoretical models. However, through the invention and continued improvements in genomic technologies, we have truly begun to unlock the genetic basis of dioecy in many species. Here we broadly review the advances in research on dioecy and sex chromosomes. We start by first discussing the early works that built the foundation for current studies and the advances in genome sequencing that have facilitated more-recent findings. We next discuss the analyses of sex chromosomes and sex-determination genes uncovered by genome sequencing. We synthesize these results to find some patterns are emerging, such as the role of duplications, the involvement of hormones in sex-determination, and support for the two-locus model for the origin of dioecy. Though across systems, there also many novel insights into how sex chromosomes evolve, including different sex-determining genes and routes to suppressed recombination. We propose the future of research in plant sex chromosomes should involve interdisciplinary approaches, combining cutting-edge technologies with the classics to unravel the patterns that can be found across the hundreds of independent origins.

Seleksi Marka SCAR untuk Identifikasi Dini Jenis Kelamin Tanaman Pepaya (The Selection of SCAR Markers for Early Sex Identification of Papaya)

<p>Identifikasi dini terhadap jenis kelamin tanaman pepaya merupakan hal penting yang dapat membantu petani dalam budidaya tanaman pepaya. Identifikasi kelamin pepaya berdasarkan marka morfologi dan fisiologi telah dilakukan, namun beberapa hasilnya masih bias karena faktor lingkungan. Identifikasi kelamin tanaman pepaya menggunakan marka molekuler bisa lebih cepat dan akurat. Penelitian tersebut telah banyak dilakukan, salah satu di antaranya adalah marka berbasis sequence characterized amplified region (SCAR) dan beberapa primer SCAR telah dihasilkan untuk identifikasi kelamin pepaya. Penelitian bertujuan untuk menyeleksi primer SCAR yang efektif dalam mengidentifikasi seks tanaman pepaya. Penelitian dilakukan pada bulan November 2018 sampai Juni 2019 di Laboratorium Molekuler dan Uji Mutu Kebun Percobaan Sumani Balai Penelitian Tanaman Buah Tropika di Solok. Primer SCAR yang diseleksi adalah W11,T12, PKBT5, Napf2, dan SDp. Tanaman referensi sebagai sampel umur 11–12 bulan adalah tanaman betina, jantan, dan hermaprodit masing-masing lima tanaman dari pepaya lokal dan Merah Delima. Hasil penelitian menunjukkan bahwa lima primer SCAR yang diuji hanya dapat membedakan tanaman betina dengan tanaman jantan dan hermaprodit tetapi belum dapat membedakan antara tanaman jantan dengan hermaprodit. Konsistensi pola amplifikasi dihasilkan dari primer SCAR W11, Napf2, dan T12 dengan posisi 800 bp. Primer SCAR W11, Napf2, dan T12 selanjutnya dapat digunakan sebagai marka untuk identifikasi kelamin tanaman betina dengan tanaman jantan dan hermaprodit.</p><p><strong>Keywords</strong></p><p>SCAR; Identifikasi; Pepaya; Jantan, Hermaprodit </p><p><strong>Abstract</strong></p><p>The determination of sex expression of papaya plants is important to farmers in its cultivation. The identification of papaya plant sex based on morphological and physiological characters have been previously carried out, however, the results were still biased due to environmental factors. Many studies have been carried out to identify this plant sex, such as the use of molecular and SCAR markers, based on sequence characterization on amplified regions. This research aims to select the SCAR primers that are effective in identifying papaya plant sex. The study was conducted from November 2018 to June 2019, at Laboratory of Molecular and Quality Testing of the Indonesian Tropical Fruit Research Institute in Solok. The selected SCAR primers were W11, T12, PKBT5, Napf2, and SDp, using a total of five female, male, and hermaphrodite plants are reference aged 11–12 month from local papaya and cv. Merah Delima. The five SCAR primers tested were only able to differentiate females from male and hermaphrodite plants. The consistency of the amplification pattern was obtained from the SCAR W11, T12, and Napf2 primers at 800 bp. In conclusion, SCAR W11, Napf2, and T12 primers are used as markers to distinguish female plants from male and hermaphrodite.</p>

Plant Sex Prediction Using Genetic Markers in Cultivated Yams (Dioscorea rotundata Poir.) in Benin

Dioscorea rotundata Poir. is mainly dioecious but it also produces monoecious individuals. Recently two genetic markers were proposed to determine the sex in this species. We tested them in 119 individuals from 101 different cultivars of the national collection of Benin to verify whether they can predict the sex observed in the field. Among the analyzed individuals, 72 were male, 37 were female, 7 were monoecious and 3 were non-flowering. Our results showed that the marker sp16, associated with the W allele (female allele), was present in all female individuals but also in more than 42% of male individuals. Thus, while the absence of sp16 confirmed the male sex of the individuals, its presence did not allow sex discrimination. The marker sp1 allowed the identification of four genotypes (AA, AB, BB and AC) in the analyzed individuals with AA and AB being the most represented. Although AA was observed in 62.16% of female individuals and AB in 83.33% of male individuals, we did not observe a clear correlation between sp1 genotypes and sex identity. We concluded that the tested markers did not allow a clear sex discrimination in Beninese Dioscorea rotundata cultivars. Our results also suggest that Beninese D. rotundata cultivars have adopted a male XX/XY heterogametic system that is undergoing reorganization.