Zanthoxylum motuoense Huang, native to Tibet, China, is a newly discovered Chinese prickly ash, which, recently, has increasingly attracted the attention of researchers. In order to understand its volatile oil compositions and flavor characteristics, and to explore the flavor difference between Z. motuoense and the common Chinese prickly ash sold in the market, we analyzed the essential oils of Z. motuoense pericarp (MEO) using HS-SPME/GC×GC-TOFMS coupled with multivariate data and flavoromics analyses. The common commercial Chinese prickly ash in Asia, Zanthoxylum bungeanum (BEO), was used as a reference. A total of 212 aroma compounds from the 2 species were identified, among which alcohols, terpenoids, esters, aldehydes, and ketones were the major compounds. The predominant components detected from MEO were citronellal, (+)-citronellal, and β-phellandrene. Six components—citronellal, (E,Z)-3,6-nonadien-1-ol, allyl methallyl ether, isopulegol, 3,7-dimethyl-6-octen-1-ol acetate, and 3,7-dimethyl-(R)-6-octen-1-ol—could be used as the potential biomarkers of MEO. The flavoromics analysis showed that MEO and BEO were significantly different in aroma note types. Furthermore, the content differences of several numb taste components in two kinds of prickly ash were quantitatively analyzed using RP-HPLC. The antimicrobial activities of MEO and BEO against four bacterial strains and nine plant pathogenic fungi were determined in vitro. The results indicated that MEO had significantly higher inhibitory activities against most microbial strains than BEO. This study has revealed the fundamental data in respect of the volatile compound properties and antimicrobial activity of Z. motuoense, offering basic information on valuable natural sources that can be utilized in the condiment, perfume, and antimicrobial sectors.

Rhododendron resources are abundant in China, and hybridization breeding technology is the primary method for cultivating Rhododendron varieties. In order to optimize the utilization of wild Rhododendron resources for distant hybridization, this study took three horticultural varieties of Rhododendron subgenus Tsutsusi and the Rhododendron decorum Franch. of the subgenus Hymenanthes as the research objects, and the cross-compatibility between subgenera was analyzed from the aspects of pollen tube growth and ovary and seed development. At the same time, the statistics of ovary swelling rate and fruit bearing rate, numbers of capsule seeds, 1000 seed weight of hybrid seeds, germination rate, green seedling rate, and other indexes were analyzed to comprehensively evaluate hybrid fertility. The results showed that there was obvious pre-fertilization and post-fertilization barriers existing in the hybridization of Rhododendron × hybridum hort. and R. decorum. During the growth of pollen tubes, a large amount of callus appeared, which led to the entanglement, distortion, and abnormal development of the pollen tubes; only part of the pollen tubes entered into the ovary or ovule. The pre-fertilization barriers can be overcome by early pollination and delayed pollination. According to the observation of the ovary paraffin section, 45 d after pollination, the seed was shriveled and developed abnormally. The comprehensive evaluation of hybrid fertility showed that ‘Sima’ × R. decorum was fertile, ‘Yin Taohong’ × R. decorum was a weakly fertile, and ‘Little Taohong’ × R. decorum was sterile. This study provided a scientific basis for intergeneric hybridization breeding between the subgenus Tsutsusi and the subgenus Hymenanthes.

The horticultural varieties of the evergreen Rhododendron 'Sima,' 'Yin Taohong' and 'Little Taohong' were used as the maternal lines, and the wild Rhododendron decorum Franch. was used as the paternal line for intergeneric crosses. Moreover, the horticultural varieties within the evergreen Rhododendron were also used as controls to study the effect of different pollination methods on hybrid compatibility. After the pollination, the rates of ovary swelling and fruit bearing, numbers of capsule seed, 1,000 seed weight of hybrid seeds, and the rates of germination and green seedlings were examined to comprehensively evaluate the degree of hybrid ability. Simultaneously, the pollen tube growth, fertilization, and hybrid embryo growth and development through the pollen tube were observed by fluorescence microscopy and paraffin sectioning to study the compatibility and histological mechanism of intersubgeneric hybridization between horticultural varieties of the evergreen Rhododendron and Rhododendron decorum Franch. This study provided a scientific basis for intergeneric hybridization breeding between the evergreen Rhododendron and the Rhododendron decorum Franch..

The Cardiocrinum giganteum is a bulbous plant with extremely high ornamental and economic values. The study revealed that seeds require an extended period of variable temperature stratification treatment to overcome dormancy and initiate germination, yet the molecular mechanisms underlying embryo dormancy release remain unclear. In this research, transcriptome profiles at different germination stages of seeds subjected to variable temperature stratification were systematically analyzed and compared, while the embryo length of corresponding seed samples was quantitatively measured. The results demonstrated that within the initial 60 days of stratification, the embryo scarcely grew. After 90 days of stratification, the embryo elongated conspicuously, and germination initiated at 130 days of stratification. The transcriptome sequencing outcomes demonstrated that the differentially expressed genes (DEGs) identified in the three comparative groups were predominantly associated with plant hormone signal transduction, carbohydrate metabolic pathways, and phenylpropanoid biosynthesis metabolic pathways. Notably, genes associated with auxin, abscisic acid (ABA), brassinosteroid (BR), ethylene, and gibberellin signaling pathways were significantly upregulated during the stratification period from 30 d to 60 d, while these genes exhibited varying degrees of significant differential expression from 90 d to 130 d. Multiple key enzymes in carbohydrate metabolic pathways exhibited marked upregulation after 90d of stratification. Notably, β-glucosidase (BGLU) genes associated with polysaccharide hydrolysis (Cluster-62345.33620, Cluster-62345.31435, and Cluster-62345.35688) showed 6.68-, 5.08-, and 6.85-fold upregulation, respectively, at 130 d of stratification. Concurrently, the glycolytic pathway was upregulated throughout the process. The majority of genes involved in phenylpropanoid biosynthesis, particularly those encoding peroxidases, were activated during stratification. The reliability and accuracy of 10 genes closely associated with C. giganteum seed germination were validated using RT-qPCR. The results demonstrated that plant hormone signal transduction, carbohydrate metabolism pathways, and phenylpropanoid biosynthesis collectively participate in the post-maturation development and germination processes of the embryo. The potential roles of certain genes in these developmental and germination stages require further investigation. These findings provide novel insights into the transcriptional regulatory mechanisms underlying dormancy release in C. giganteum seeds. The candidate genes identified in this study warrant functional characterization and may contribute to advancing the understanding of seed dormancy and germination in plants.