Jianjun Chen

Phosphorus (P) loss to aquatic systems poses a dual challenge of eutrophication and depletion of finite phosphate‐rock resources. This study developed chitosan (CS) hydrogel beads containing CaFe layered double hydroxide (LDH) for phosphate removal and potential nutrient reuse. Incorporation of CaFe‐LDH increased the BET specific surface area from 6 to 28 m ² g ^{− 1} and enhanced phosphate adsorption. Among six formulations, CS/CaFe4 exhibited the highest phosphate adsorption capacity and was selected for further evaluation. Phosphate adsorption approached equilibrium within approximately 8 h. The maximum experimental adsorption capacity was approximately 42 mg P g ^{− 1} , and the Langmuir‐estimated maximum capacity was 41.8 mg P g ^{− 1} , although the Freundlich model provided a slightly better fit than the Langmuir model. Phosphate adsorption remained relatively stable from pH 4 to 11 but declined sharply at pH 3. Cl ⁻ , NO ₃ ⁻ , and SO ₄ ^{2 −} had limited effects, whereas HCO ₃ ⁻ reduced adsorption and Ca ^{2 +} and NH ₄ ⁺ enhanced phosphate adsorption. Phosphate‐loaded hydrogel released 0.10–0.14 mg P L ^{− 1} in each of five sequential 24‐h water‐extraction cycles. In a 14‐day wheat ( Triticum aestivum ) bioassay, observed seed germination was higher with phosphate‐loaded hydrogel than in unamended soil; however, fresh hydrogel produced a similar response, whereas superphosphate produced the highest germination. Seedling length was similar among treatments. Collectively, these results identify CS/CaFe4 as a promising material for P capture and demonstrate that a measurable fraction of adsorbed P can be released from the phosphate‐loaded hydrogel. Longer‐term soil and plant studies are needed to determine P bioavailability, fertilizer value, and the feasibility of agricultural reuse.

Vanilla planifolia, the principal source of natural vanilla flavor, is an economically important aromatic and medicinal crop. Its genetic improvement is constrained by a narrow cultivated genetic base, extensive clonal propagation, the long juvenile period before plants reach reproductive maturity, and limited cytogenetic information for wild relatives and interspecific hybrids. This study estimated 2C nuclear DNA content in 91 Vanilla accessions maintained at the University of Florida Tropical Research and Education Center, including 56 V. planifolia accessions, 21 accessions representing nine additional taxa, and 14 recorded interspecific hybrids. Young apical node tissue was co-chopped with Oryza sativa ssp. japonica ‘Nipponbare’ (2C = 0.795 pg), stained with propidium iodide, and analyzed by flow cytometry. Vanilla planifolia ranged from 3.32 to 4.13 pg 2C (3.25–4.04 Gbp equivalents), with a mean of 3.78 pg 2C (3.52 Gbp). Among the other taxa, V. phaeantha averaged 3.60 pg 2C (3.52 Gbp), whereas V. barbellata averaged 6.30 pg 2C (6.16 Gbp). The eight V. pompona accessions ranged from 5.74 to 6.19 pg 2C (5.61–6.05 Gpb). Recorded interspecific hybrids ranged from 3.57 to 7.36 pg 2C (3.49–7.20 Gbp). Several hybrid-designated accessions fell outside simple expectations based on the observed parental-species ranges, but flow cytometry alone cannot distinguish ploidy, aneuploidy, parentage, or peak-assignment effects associated with endoreplication. These data provide a comparative baseline for germplasm curation and identify accessions that warrant chromosome counting, molecular identification, parentage verification, and reproductive evaluation before breeding interpretation.

Introduction: Kratom ( Mitragyna speciosa ) has gained increasing interest due to its unique leaf alkaloids with pharmacological potential. Comparisons of climate conditions in Florida production areas with those in the plant’s native habitat in Southeast Asia indicate a need to better understand how light quality, particularly ultraviolet (UV)-B radiation, influences plant growth and alkaloid biosynthesis. This study evaluated the effects of far-red (FR) light supplementation and end-of-day (EOD) UV-B exposure on plant growth, photosynthetic performance, and leaf alkaloid content of kratom. Methods: Plants were grown under controlled-environment conditions under five light treatments: white (W) light alone; W plus 1 or 2 h of EOD UV-B exposure; and W supplemented with FR light combined with 1 or 2 h of EOD UV-B exposure. Total photosynthetic photon flux density (PPFD) was maintained at 300 µmol·m ⁻² ·s ⁻¹ , with additional supplemental FR and EOD UV-B provided at 90 and 0.3 µmol·m ⁻² ·s ⁻¹ , respectively. Plant growth, photosynthesis, and alkaloid content were analyzed. Results: Low-dose EOD UV-B had minimal effects on plant architecture and leaf growth, but slightly reduced leaf biomass and photosynthetic capacity. Extending EOD UV-B exposure from 1 to 2 h reduced the stem caliper by 20%, branching by 14%, and new leaf area by 14%. Supplementation with FR at 30% of total PPFD induced a shade-avoidance response, increasing plant height by 58% to 76% while reducing leaf number, photosynthesis, and biomass. Corynantheidine concentration in leaves increased by 175% under W plus 1 h of EOD UV-B, whereas speciociliatine, mitraciliatine, and isopaynantheine decreased in aging leaves. Conclusions: Light-quality-induced stress can modify alkaloid accumulation in kratom, and these responses must be carefully balanced against reductions in growth and biomass. These findings improve understanding of environmental regulation of kratom alkaloid biosynthesis and provide a basis for designing lighting strategies to optimize both biomass production and the accumulation of desirable alkaloids.

Fittonia Coem. is a widely cultivated ornamental foliage genus, but the taxonomy and relationships of cultivated forms remain poorly resolved because traditional classifications rely heavily on variable foliar traits. In this study, we investigated the genetic relationships and phenotypic variation among 14 commercially available Fittonia cultivars using amplified fragment length polymorphism (AFLP), methylation-sensitive amplified fragment length polymorphism (MSAP), DNA flow cytometry, chromosome counting, and comparative morphological and anatomical analyses. Morphological character states were further mapped onto AFLP- and MSAP-derived phylograms to assess their evolutionary patterns and taxonomic relevance. AFLP and MSAP analyses consistently recovered two well-supported clusters within the cultivated material examined: Clade I, comprising ‘Titanic’ and ‘Angel Snow’, and Clade II, comprising the remaining 12 cultivars. These clades were independently supported by stable differences in trichome morphology, cystolith distribution, epidermal cell form, leaf venation architecture, and stem anatomy. In contrast, several traditionally used diagnostic characters, including leaf vein color and petiole length, were found to be homoplastic or continuously variable. Chromosome counts and flow cytometry indicated that all cultivars were diploid (2n = 36) and exhibited limited variation in genome size. Together, these results provide integrative evidence for two distinct clusters within cultivated Fittonia. However, because sampling was limited to commercially available cultivars, the relationship of these clusters to currently recognized species remains unresolved. Our findings highlight the limitations of traditional trait-based classifications and underscore the need for broader sampling, including wild populations, to reassess species boundaries in the genus.

Jaboticaba (Plinia cauliflora) is a slow-growing, ornamental fruit tree suited to Florida’s climate (Zones 9a–11). It thrives in acidic, consistently moist soils under partial shade, producing fruit with nutritional and medicinal value. Its unique cauliflory and flaking bark make it a distinctive addition to home landscapes. Moreover, once established, the tree is relatively low maintenance. For home gardeners, the publication provides an overview of growing jaboticaba in Florida and a brief review of the fruit's nutraceutical value. Florida gardeners can enjoy increased pollination and biodiversity in the yard, as well as fruit with health benefits.

Begonia L. is one of the largest and most horticulturally diverse genera of flowering plants, with more than 2,200 accepted species and exceptional variation in growth habits, foliage morphology, flower forms, ecological specializations, and reproductive biology. This review synthesizes current knowledge of Begonia taxonomy, biogeography, germplasm resources, cytogenetics, domestication, breeding history, molecular markers, and biotechnology, emphasizing their relevance to ornamental improvement. Major commercial groups, including wax, cane-like, rhizomatous, Rex Cultorum, tuberous, Lorraine, Elatior, and modern interspecific bedding begonias, were developed largely through interspecific or intersectional hybridization followed by recurrent phenotypic selection. Although these groups exhibit substantial ornamental diversity, they were derived from a relatively small number of founder species, leaving much of the wild germplasm underutilized. Cytogenetic studies reveal extensive variation in chromosome numbers, repeated polyploidization, and the formation of 2n gametes through first division restitution, all of which have direct implications for wide hybridization and polyploid breeding. Tissue culture, mutation breeding, chromosome doubling, and Agrobacterium-mediated transformation have been established in selected species and hybrids, while chromosome-scale genome assemblies, transcriptome analyses, and metabolomic datasets are beginning to support candidate-gene discovery. However, practical application remains constrained by genotype-dependent regeneration, a lack of breeder-ready markers, few mapping populations, and the absence of stable gene-edited Begonia lines. Future progress will depend on integrated breeding platforms that combine conserved wild germplasm, cytogenetic screening, genomic resources, genome-editing tools, tissue-culture systems, and multi-environment evaluation to broaden the genetic base and accelerate cultivar development.

Introduction: Kratom (Mitragyna speciosa), a medicinally valuable ethnobotanical tree native to Southeast Asia, has traditionally been used to combat fatigue and enhance productivity. Recently, it has gained attention in North America and Europe for its potential therapeutic applications, particularly in pain management and opioid withdrawal, positioning it as a candidate for drug development. Postharvest processing is a critical stage that influences chemical transformations of bioactive compounds, yet its impact on kratom remains poorly understood.Methods: This study investigated the effects of withering duration, drying temperature, cultivar, and season on kratom alkaloid composition and concentration. In Study I, leaves of cultivar Hawaii underwent four withering durations (0, 12, 24, 72 h) followed by drying at five temperatures (−40, 25, 40, 60, 80 °C). In Study II, leaves of cultivar MR-Malaysian were tested under two withering durations (0, 12 h) and two drying temperatures (25, 60 °C). Both studies were conducted across two seasons.Results: Withering generally increased mitragynine concentrations by 14-65% (w/w) in 'Hawaii' and 3-8% in 'MR-Malaysian' in leaf alkaloid extracts. A 12-h withering followed by drying below 40 °C enhanced speciogynine and paynantheine in 'Hawaii' by 37-48% and 35-67%, respectively. Low drying temperatures preserved mitragynine, speciogynine, and paynantheine across cultivars. The average 7-hydroxymitragynine content in leaf alkaloid extracts ranged from 0.02-0.04% and was detected only in specific seasons, varying by cultivar, suggesting genotype-environment interactions.Discussion: This study demonstrates for the first time that kratom alkaloid composition and concentration are substantially influenced by genotype, season, and postharvest handling. These findings underscore the importance of optimizing postharvest processing strategies to enhance beneficial alkaloid profiles in kratom.