In this paper, the history of flax breeding, the types, research methods, occurrence, and genetic mechanism of apomixis were reviewed. The development and genetic mechanism of apomixis in polyembryonic flax, the progress in inducing methods and other aspects was discussed by cytology, embryology, genetics, and molecular biology, etc., methods in this paper. The purpose of this study was to reveal the rules of apomixis and to improve the utilization efficiency of apomixis in breeding. The problems existing in apomixis breeding of polyembryonic flax and the research direction of apomixis of flax were put forward.

Flowering regulation in hemp is critical for determining fiber yield, seed production, and the accumulation of medicinal components. This paper, based on bibliometric analysis, highlights the current gap in basic research on cannabis floral organs. The latest advancements in flowering regulation are then systematically reviewed. The morphological and physiological foundations of flowering are examined, including the flowering phenotype, timing, and flower differentiation. Furthermore, the direct regulatory mechanisms of key environmental and cultivation factors—such as photoperiod (type, light quality, duration) and plant nutrition (fertilization, hormones)—on flowering are discussed. Potential pathways through which biotic and abiotic stresses indirectly affect flowering by disrupting metabolic processes are also explored. In addition, the genetic basis of flowering regulation, including key gene loci such as Autoflower1, Early1, and CsPRR37, as well as molecular networks like the FT-mediated photoperiod pathway and the miR156-SPL age pathway, is examined in detail. Finally, the industrial significance of flowering regulation is summarized, and future research directions are proposed to provide a theoretical foundation for the precise breeding and cultivation management of high-quality hemp varieties.

The conventional method of raising seedlings with plastic trays has drawbacks, including large plastic tray consumption, difficulty in recycling and potential farmland white pollution, along with high labor input and production costs. To clarify the effects of tray-free simplified rice seedling raising technology, which uses biodegradable biomass seedling films to replace traditional plastic trays on rice grain yield and its components, large-scale comparative field experiments were conducted in seven major rice-producing counties of Heilongjiang Province from 2022 to 2024. Independent-sample t-tests, linear mixed-effects models and structural equation modeling were applied to systematically evaluate the application effects of this technology. The results showed that the average grain yield of the treatment group reached 9032 kg/ha, which was a significant increase of 5.93% compared with the 8526.0 kg/ha of the control group. Compared with the conventional method, this technology markedly increased the effective panicle number, the filled grain number per panicle and 1000-grain weight, and reduced the percentage of unfilled grains, presenting positive yield performance across different regions, although the magnitude of increase varied (2.7–9.5%). Based on the previous literature, this technology has the potential to reduce plastic use and its associated environmental impacts, although direct measurements of carbon emissions and degradation rates were not conducted in this study. Featuring potential ecological benefits and simplified cultivation with prominent yield-increasing effects, it is worthy of popularization and application in cold-region rice planting areas.

This study aims to elucidate the molecular mechanisms underlying cyanogenic glycoside accumulation in flax. As an important oil and fiber crop, the nutritional value of flax is compromised by the toxicity of cyanogenic glycoside. To clarify the key genetic regulators and temporal patterns of cyanogenic glycoside biosynthesis, transcriptomic sequencing was performed on seeds from high- and low-cyanogenic glycoside flax varieties (‘MONTANA16’ and ‘Xilibai’) at three developmental stages: bud stage, full flowering stage, and capsule-setting stage. A total of 127.25 Gb of high-quality data was obtained, with an alignment rate exceeding 87.80%. We identified 31,623 differentially expressed genes (DEGs), which exhibited distinct variety- and stage-specific expression patterns. Principal component analysis (PCA) and hierarchical clustering demonstrated strong reproducibility among biological replicates and revealed the seed pod formation stage as the period with the most significant varietal differences, suggesting it may represent a critical regulatory window for cyanogenic glycoside synthesis. GO and KEGG enrichment analyses indicated that DEGs were primarily involved in metabolic processes (including secondary metabolism and carbohydrate metabolism), oxidoreductase activity, and transmembrane transport functions. Of these, the cytochrome P450 pathway was most significantly enriched at the full bloom stage (H2 vs. L2). A total of 15 LuCYP450 and 13 LuUGT85 family genes were identified, and their expression patterns were closely associated with cyanogenic glycoside accumulation: In high-cyanogenic varieties, LuCYP450-8 was continuously upregulated, and LuUGT85-12 was significantly activated during later stages. Conversely, in low-cyanogenic varieties, high expression of LuCYP450-2/14 may inhibit synthesis. These findings systematically reveal the genetic basis and temporal dynamics of cyanogenic glycoside biosynthesis in flax and highlight the seed pod formation stage as a decisive regulatory window for cyanogenic glycoside synthesis. This study provides new insights into the coordinated regulation of cyanogenic pathways and establishes a molecular foundation for breeding flax varieties with low CNG content without compromising agronomic traits.