Crop rotation and diversification (CRD) are crucial strategies in sustainable agriculture, offering multiple benefits to both farmers and the environment. By alternating crops or introducing diverse plant species, CRD practices improve soil fertility, reduce pest populations, and enhance nutrient availability. For example, legume-based rotations increase soil nitrogen levels through biological nitrogen fixation, reducing the need for synthetic fertilizers. Moreover, these practices promote more efficient water and nutrient use, reducing the reliance on synthetic fertilizers and minimizing the risk of pests and diseases. This review synthesizes findings from recent research on the role of CRD in enhancing sustainable agriculture and resilience, highlighting the potential contributions of these practices towards climate change mitigation and adaptation. Specific crop rotation systems, such as the cereal–legume rotation in temperate regions and the intercropping of maize with beans in tropical environments, are reviewed to provide a comprehensive understanding of their applicability in different agroecological contexts. The review also addresses the challenges related to implementing CRD practices, such as market demand and knowledge transfer, and suggests potential solutions to encourage broader adoption. Lastly, the potential environmental benefits, including carbon sequestration and reduced greenhouse gas emissions, are discussed, highlighting the role of CRD in building resilient agricultural systems. Collectively, this review paper emphasizes the importance of CRD methods as sustainable agricultural practices and provides key insights for researchers and farmers to effectively integrate these practices into farming systems.

Camellia oleifera, a widely cultivated woody oil crop, holds economic significance because of its ability to grow without encroaching on cultivated land. The pericarp of C. oleifera is abundant in flavonoids and phenolic acids, which offer significant nutritional benefits. This study used metabolomic technology (UPLC-ESI-MS/MS) to discern metabolite variances in the pericarp of three C. oleifera types (COT, BFOT, and SFOT) during the maturity stage and subsequently analyzed and compared them. A total of 1117 metabolites were detected in the study, including 277 flavonoids, 221 phenolic acids, 108 lipids, 93 amino acids and their derivatives, 83 organic acids, 59 nucleotides and their derivatives, 57 alkaloids, 52 lignans, 44 tannins, 23 terpenoids, and 100 miscellaneous metabolites (such as sugars, alcohols, vitamins, and other unclassified substances). Clustering and PCA analyses revealed distinct separation of COT, BFOT, and SFOT, indicating variances in metabolites within the pericarp peels of these three C. oleifera types. KEGG enrichment analysis demonstrated that 143 shared differential metabolites were primarily associated with amino acid biosynthesis. These findings are expected to significantly enhance the current knowledge of the C. oleifera pericarp and pave the way for future development and use efforts.

The taxonomy of an ancient gymnosperm genus Taxus, with high value in horticulture and medicine, is perplexing because of few reliable morphological characters for diagnosing species. Here, we performed a comprehensive investigation of the evolutionary dynamics of Taxus chloroplast genomes and estimated phylogenetic relationships, divergence times, and ancestral distributions of Taxus species by comparing 18 complete chloroplast genomes. The variations across the chloroplast genome of different Taxus species indicated that remarkably varied genome variations across lineages have reshaped the genome architecture. Our well-resolved phylogeny supported that T. brevifolia Nutt. was basal lineages followed by the other North America lineages. Divergence time estimation and ancestral range reconstruction suggested that the Taxus species originated in North America in the Late Cretaceous and revealed that extant Taxus species shared a common ancestor whose ancestral distribution area was probably in North America and afterwards the earliest members expanded to Southeast Asia from where Chinese Taxus species originated. The predominant European species have more closer relationship with the Eastern Asian species and the speciation of Eurasia species arose from several dispersal and vicariance events in the Miocene. Genome-wide scanning revealed 18 positively selected genes that were involved in translation and photosynthesis system in Taxus, which might be related to the adaptive evolution of Taxus species. The availability of these complete chloroplast genomes not only enhances our understanding of the elusive phylogenetic relationships and chloroplast genome evolution such as conservation, diversity, and gene selection within Taxus genus but also provides excellent templates and genetic bases for further exploration of evolution of related lineages as well as for plant breeding and improvement.

Chinese pepper, referring to Zanthoxylum bungeanum Maxim. and Zanthoxylum armatum DC. species, is an important spice crop that has long attracted people’s interest due to its extensive application in Asian cuisine to improve taste. Numerous cultivars have been developed during the long history of domestication and cultivation. However, little to no information is available on the genetic diversity and evolutionary relationships of Chinese pepper cultivars and their historical diversification has not been clarified. Herein, we sequenced two nrDNA non-coding region markers, the external transcribed spacer (ETS) and the internal transcribed spacer 2 (ITS2), to assess genetic diversity and phylogenetic relationships among 39 cultivated and wild populations of Chinese pepper from eight provinces and to address the question of ancient demographic trends which were probably influenced by changing climate during evolutionary history. In total, 31 haplotypes were identified based on 101 polymorphism sites. Our results revealed relatively high level of genetic variation despite long-term cultivation of this crop. AMOVA revealed that genetic variation existed predominantly within provinces rather than among provinces. The genetic structure result based on haplotype network analysis largely reflected historical records, which suggested a Gansu origin for Chinese pepper and an ancient west-to-east spread of Chinese pepper circulating in China. We also provided evidence that changing Pleistocene climates had shaped the demographic trends of Chinese pepper. Taken together, our findings not only suggest that Chinese pepper is a dynamic genetic system that responds to evolutionary forces, but it also provides a fundamental genetic profile for the conservation and responsible exploitation of the extant germplasm of Chinese pepper and for improving the genetic basis for breeding the cultivars.

Zanthoxylum, belonging to the Rutaceae family, is widely distributed in tropical and subtropical regions. The genus has high economic value as spices, oils, medicinal plants, and culinary applications. Zanthoxylum has a long history of domestication and cultivation in China. However, the phylogenetic relationships and origin of wild and cultivated Zanthoxylum species in China remain largely unknown. Moreover, there is still no clear molecular phylogenetic system for Zanthoxylum species. Herein, 373 Zanthoxylum samples were collected from all presently known provenances of Zanthoxylum in China. In this study, four chloroplast DNA (cpDNA) markers (matK, ndhH, psbB, rbcL) were used to comprehensively analyze the genetic diversity, relatedness, and geographical origin of Chinese Zanthoxylum species. The results were as follows: (1) The aligned length of the four pairs of cpDNA sequences was 3836 bp, and 68 haplotypes were identified according to 219 variable polymorphic sites, including 90 singleton variable sites, 129 parsimony informative sites, 3 Indels (insertions and deletions). (2) Phylogenetic tree and haplotype network strongly supported the division of Zanthoxylum species consistent with the taxonomic recognition of five species: Z. bungeanum, Z. piasezkii, Z. piperitum, Z. armatum, and Z. micranthum. (3) Divergence time estimation suggested that Zanthoxylum genus originated from the Late Eocene, and most Zanthoxylum species diverged after the Middle Miocene. (4) Haplotype 16 (H16) was at the bottom of the phylogenetic tree, had higher haplotype diversity (Hd) and nucleotide polymorphism (Pi) than other haplotypes, and was located in the center of the network figure. Therefore, we deduced that the cultivated Zanthoxylum species may originate in Zhouqu County, Gansu Province, China. Meanwhile, our research provided a scientific basis for the identification and breeding programs of Chinese Zanthoxylum species.