Plant Species Research Articles

Effects of silicon application on <i>Betula pendula</i> seedlings

Silicon (Si) is a beneficial element for many plant species, conferring resistance to drought and herbivory, but its effects on trees are less known. We studied responses of silver birch (<i>Betula pendula</i>), grown in peat, to liquid Si supplementation (Si concentration 0.65 mM) on 1) growth, 2) water economy and 3) element accumulation plus 4) feeding preference of an insect, <i>Epirrita autumnata</i> and a mammalian herbivore, <i>Microtus agrestis</i>. Plant growth was not affected but control (Si–) plants shed their old leaves earlier. Detached Si+ leaves lost water 11%-units less than Si–, and the integrated water-use efficiency based on <sup>13</sup>C analysis was higher in Si+. Foliar Se was higher and Mn and S lower in Si+. Root Mg concentrations were higher and Pb lower in Si+. <i>Epirrita autumnata</i> did not prefer either treatment, but <i>M. agrestis</i> preferred Si– stems. Silicon improved birch water relations as indicated by the leaf drying resistance and increased water-use efficiency. The changes in metal accumulation were probably beneficial, but the lower S/Se ratio requires attention. Furthermore, Si decreased palatability to a mammalian herbivore. Using Si as fertilizer in nurseries could be possible to increase birch tolerance to water stress and herbivory.

Structures of Forest Stands in Monospecific Reforestations Based on Tectona grandis Lf. (Verbenaceae) in the Sangoué Classified Forest in Côte d’Ivoire

Teak-based reforestation poses the challenge of sustainable development in terms of meeting economic, social and environmental needs. In order to meet the needs of populations for timber and contain anthropogenic pressures on flora, reforestation based on Tectona grandis is initiated in the Sangoué Classified Forest. Therefore, a diagnostic study is therefore essential to assess the effects of this practice on the environment. This study assessed the consequences of planting Tectona grandis on the conservation and restoration of the Sangoué classified forest. For this, the structural and floristic characteristics of teak stands at different stages of evolution were compared. The results showed that young plots have more plant species, are more diverse and more evenly distributed. Older plots have the highest densities and basal areas of stems, with an inverted J-shaped distribution. Young plots have the lowest densities and basal areas, as well as a more regular horizontal structure. The woody species introduced into reforestation are Tectona grandis, Gmelina arborea and Cedrela odorata. In the 33-year-old block, the total basal area value is 18.07 m² per hectare, then 13.72 m² per hectare in the 30-year-old block. As for the 25- and 28-year-old blocks, the basal area values per hectare are 12.61 m2 and 9.39 m2 respectively. Young plots promote natural regeneration and floristic diversity, while older plots present low floristic diversity with reduced structural balance. Introduced species have benefited more from teak planting than native ones. Teak planting may lead to profit, but it presents challenges for biodiversity. The impact of teak planting on the Sangoué classified forest differs depending on the stage of evolution of the stands. Therefore, it has advantages and disadvantages for forest restoration and conservation. The teak plantation needs to be adjusted to forest management.

Investigating Transfer Learning based CNN for Multi-Crop Disease Recognition in Horticulture Crops using Wireless Multimedia Sensor Network

Introduction: Achieving sustainable growth in agricultural productivity is crucial for addressing various challenges confronting food systems globally. One of the key aspects is effectively identifying and addressing diseases that can adversely affect crop quality and yield. Method: This research study proposes the use of Wireless Multimedia Sensor Network (WMSN) in conjunction with deep transfer learning model for disease detection in horticulture crops. The proposed system utilizes the image data of horticulture crops obtained using WMSN for performing a comparative assessment of several pre-trained deep learning models, encompassing VGG, ResNet, MobileNet, Inception, Xception, DenseNet, and EfficientNet, to ascertain their effectiveness in identifying diseases across a range of horticultural plants. The models undergo fine-tuning using transfer learning technique and are assessed on different measures, such as accuracy, precision, recall, F1 score, and the number of epochs needed for convergence using the image data obtained from WMSN. Results: Among the compared models, EfficientNetB3 appears as the best performing model, surpassing others in all evaluation metrics while also exhibiting low parameters and a compact size. Notably, EfficientNetB3 achieves a testing accuracy of 93.69% and a training accuracy of 98.85% after only 21 epochs of training. In contrast, DenseNet201, DenseNet169, and EfficientNetB0 demonstrate performance close to the best-performing models, but they have higher parameters or sizes. On the contrary, ResNet50, InceptionV3, and Xception exhibit poorer performance, presumably due to their substantial size in relation to the dataset. Conclusion: This analysis provides valuable insights for optimizing the top-performing models for disease classification across various plant species. Moreover, the fine-tuned EfficientNetB3 model shows potential for integration with mobile devices, facilitating real-time disease classification.

Short‐term survival and growth of 32 native boreal plants on treated oil sands tailings

AbstractThe consolidation of oil sands tailings is a cost‐ and time‐consuming process that requires treatment via active (e.g., centrifugation) and passive (e.g., self‐weight consolidation) methods. The use of plants to dewater tailings is a promising concept and has previously been evaluated using agronomic grass species in greenhouse studies. This greenhouse study evaluated the short‐term survivorship and growth of 32 upland and lowland native plant species (12 forbs, 14 graminoids, and six woody plants) in centrifuged tailings and benchmarked their performance against reclamation soil and undisturbed forest soil. All plant species were propagated from seed and transplanted as seedlings into containers filled with one of the three substrates. After 42 days, the height (woody species only) and total aboveground biomass were determined for all living plants. As expected, the mortality of seedlings in tailings was higher than plants grown in the other two substrates. Graminoid species, regardless of species community type (wetland or upland), had higher survival probabilities and growth compared to forb or woody species across all substrates. Of forbs and woody species evaluated, Geum aleppicum and Populus tremuloides showed the most promise amongst the upland species, and Rumex occidentalis was the wetland equivalent.

Adaptation of Different Bamboo Species in Central Zone of Tigray, Northern Ethiopia

Bamboo is the plant species under the family Poaceae, subfamily Bambusoideae. Bamboo is one of the species with greatest diversity in the world comprising about 1,642 species under 121 genera. However, only two species of bamboo are native to Ethiopia. Therefore, this study is designed to evaluate the performance of 9 introduced bamboo species namely: Dendrocalamus asper, Dendrocalamus fuminensis, Dendrocalamus diananensis, Dendrocalamus membranaceus (CV.grandis), Dendrocalamus barbatus, Dendrocalamus laosensis, Bambusa long internode, Bambusa polymorpha, and Bambusa lapidea in Tahtay-maichew district, central Tigray. The design of the experiment is Randomized Complete Block Design (RCBD) with three replications. The total size of the experimental field is 1,680 m2 and the spacing between each blocks and plots is 3 m and 2 m, respectively. There are 10 plots having an area of 30 m2 for each replication. A total of 180 bamboo seedlings were planted in the experiment. The collected data was analyzed using One-way ANOVA. The overall statistical difference in the survival capability of the species was not significant (P = 0.47) and 100% survival capability was observed by all species. The root collar diameter of the different bamboo species shows significant variation (P = 0.003). The highest root collar diameter (1.12±0.06 cm) was observed in the species D. membrenaceus. The highest diameter at stump height (0.87±0.03 cm) was observed by the species B. long internode, followed by D. membrenaceus (0.73±0.04 cm). The highest culm height was observed in the species Bambusa long internode (128±5.9 cm), followed by D. membrenaceus (102±6.8 cm), and the least culm height (49.7±8.8 cm) was observed in O .abyssinica, followed by B. lapidea (77.9±7.4 cm). In general, all nine species showed a very good adaptability to the site and should be included as part of the natural resource development and utilization process.

The finding of black currants from sect. Eucoreosma (Grossulariaceae) in the central part of southern Primorsky Territory, Russia

Background. The ever increasing anthropogenic impact on natural populations of rare and, especially, endangered plant species has recently become even more forceful. Therefore, the finding of a small black currant population representing sect. Eucoreosma (Spach) Jancz. within a natural environment in the south of Primorsky Territory appears highly important. Previously, none of the black currant species was recorded as occurring in this area. Materials and methods. Plants from the new locality were compared with accessions of Ribes nigrum L., R. ussuriense Jancz., R. pauciflorum Turcz. ex Pojark., and R. fontaneum Boczkarn. using morphological and molecular genetics techniques. Results and conclusion. A molecular genetics analysis of two chloroplast DNA fragments excluded any association of the discovered plants with R. nigrum or R. fontaneum. Meanwhile, no differences in chloroplast DNA fragments were found between these plants and R. ussuriense and R. pauciflorum accessions. A number of morphological features attested to a possibility to attribute the finding to the rare species R. ussuriense: its isolated localities had previously been reported in southern Primorsky Territory. The differences in chloroplast DNA fragments between the Siberian/Far Eastern species R. pauciflorum and the European/Siberian species R. nigrum make doubtful their possible fusion, based only on morphological characters, and require further studies.

Experimental species removal reveals species contributions to positive pollinator-mediated reproductive interactions.

Pollinator-mediated reproductive interactions among co-flowering plant species provide a canonical example of how biotic factors may contribute to species coexistence, yet we lack understanding of the exact mechanisms. Flowering-dominant and unusually attractive "magnet species" with disproportionate contributions to pollination may play key roles in such reproductive interactions, but their relative roles within the same community have rarely been assessed. We experimentally removed either a flowering-dominant or a highly attractive magnet species and compared effects on visitation frequency, pollinator richness, and seed set of co-flowering plants. Removal of either the flowering-dominant species or the magnet species reduced community-level pollinator visitation. Removal of the magnet species had the most consistent effect, including reduced pollinator visitation and richness, and reduced seed set of most co-flowering plants. These results suggest that the magnet species, which interacts with a wider range of pollinator species than does the dominant species, promotes the visitation and reproductive fitness of most other species. Removal of the flowering-dominant species affected only certain species, perhaps because these plants had floral traits similar to the dominant species. Our results highlight the role of attractive magnet species within a community in structuring reproductive interactions and identify potential mechanisms involved in coexistence facilitated by reproductive interactions.

Soil acidification controls invasive plant species in the restoration of degraded Cerrado grasslands

The Cerrado, South America's largest savanna, has acidic, nutrient‐poor soils and its native plants thrive under these conditions. However, abandoned pastures historically undergo changes in chemical properties due to interventions like liming and fertilizer use. This favors invasive African grasses and hinders native plants, impacting restoration efforts. In a Cerrado grassland undergoing restoration study, we tested whether soil acidification could restore native soil conditions and control invasives using 56 plots across 14 blocks. We hypothesized that decreased soil pH and nutrient availability would reduce invasive biomass and enhance diversity. We show that acidification reduced invasive biomass by 71%, with acidification negatively affecting invasives while sparing natives. Maintaining nutrient‐poor soil conditions can help to control invasive grasses in restoration projects, as fertilizer application can favor invasive species establishment. Soil acidification effectiveness depends on local nutrient levels. Areas with high soil cation content may require larger amendment quantities. Restoration strategies in nutrient‐poor ecosystems should aim recovering historical soil conditions to control invasives growth and support slow‐growing native plants.

Mass concentrations, compositions and burial fluxes of nano- and micro-plastics in a multi-species saltmarsh

Plastic pollution poses a serious threat to marine ecosystems; yet quantifying the mass concentrations of nano- and microplastics (NMPs) in saltmarsh sediments at the ocean-land interface remains a critical research gap. Here, the study employed reliable and efficient analytical techniques, namely pressurized liquid extraction and the double-shot model of thermal desorption/pyrolysis-gas chromatography-mass spectrometry, to quantify six different types of NMPs in the sediment of a multi-species saltmarsh, providing the first comprehensive assessment of NMP mass concentration and burial in this saltmarsh environment. The results demonstrate that polyethylene, polyvinyl chloride, and polypropylene dominated the NMP composition in sediments, constituting 72.6%, 17.3%, and 4.5% of the total NMPs, respectively. The measured NMPs represent an anthropogenic intrusion, constituting 0.10%–0.23% of the carbon storage in the saltmarsh. By examining the vertical concentration profiles, this study unveiled the influence of saltmarsh vegetation on NMP deposition in sediments, establishing a connection with local sedimentation patterns and the historical zonation of plant species such as Scirpus mariqueter, Phragmites australis and Spartina alterniflora. These findings underscore the crucial role of saltmarsh vegetation in facilitating NMP settling and retention, highlighting the necessity of considering vegetation dynamics in examining the emerging NMP pollution in coastal wetlands.

First record of <i>Pancratium maritimum</i> L. (Amaryllidaceae) for the Friuli Venezia Giulia region, Italy

We report the first observation of the psammophyte plant species Pancratium maritimum L. (Amaryllidaceae) in the Friuli Venezia Giulia region, Italy. Four adult individuals were observed in spring 2023 on the residual dunes of Lignano Sabbiadoro municipality behind a beach resort. Although we lack genetic analysis to determine its provenance, considering the absence of locally cultivated individuals and the expansion of the species in the neighboring region of Veneto, with individuals located ca. 20 km from this reported observation, we believe that its arrival in Friuli Venezia Giulia should be considered a spontaneous spread of a new native species for the region. This finding indicates that the species now has a distribution extending along the entire Italian coastline.

Intraspecific diversity of multiple plant species shows no change across an urbanization gradient

Intraspecific diversity of multiple plant species shows no change across an urbanization gradient

Temporal host–symbiont dynamics in community contexts: Impacts of host fitness and vertical transmission efficiency on symbiosis prevalence

Abstract Symbiotic associations play a role in plant ecology and evolution, but the outcome of the interaction depends on the life‐history traits of the partners and the environmental context. Although symbiosis with vertically transmitted microorganisms should result in mutualism, it is not clear how the transmission process aligns with the outcome of the context‐dependent symbiosis. For 3 years, we sampled individuals of an annual plant species that forms symbiosis with a vertically transmitted fungal endophyte, in paired stands of two contrasting vegetation communities (humid mesophytic meadows [HMM]: productive/low stress, and humid prairies [HP]: less productive/high stress). We estimated the prevalence of symbiosis at the population level, and the fitness of the plant, the symbiotic status and vertical transmission efficiency at the individual level. Over 3 years, the prevalence of symbiosis was ≈100% in HMM and ≈75% in HP. Plant fitness was very low and high in years with precipitation below and above the yearly mean, respectively. The higher fitness of endophyte‐symbiotic plants was evident in the HMM and high precipitation years. Vertical transmission of endophytes was higher in HMM (≈96%) compared to HP (≈93%) and was not related to plant fitness. Despite transmission inefficiencies in HP, changes in prevalence within the growing season (from seeds to the final plant stand) suggest a fitness advantage for symbiotic plants. Vertical transmission is expected to promote mutualism as it aligns partners' fitness. Although symbiotic plants showed higher fitness and the probability of transmission failures was higher among low‐fitness plants, the variation in transmission efficiency between plants and vegetation communities was not related to the fitness of the individual host. Our study provides evidence that context‐dependent vertical transmission efficiency and endophyte‐mediated fitness advantages interact complexly to determine the prevalence of symbiosis in populations that occur in contrasting vegetation communities. Read the free Plain Language Summary for this article on the Journal blog.

Gastroprotective Efficacy of North African Medicinal Plants: A Review on Their Therapeutic Potential for Peptic Ulcers

ABSTRACTPeptic ulcer disease remains a prevalent gastrointestinal disorder worldwide. Current treatments often have limitations, sparking interest in alternative therapies from medicinal plants. This review examines the gastroprotective potential of 54 North African medicinal plants against peptic ulcers. An extensive literature search was conducted, focusing on plants with preclinical and clinical evidence of anti‐ulcer efficacy and documented use in North African traditional medicine. The review identified several promising plant species, such as licorice (Glycyrrhiza glabra), chamomile (Matricaria chamomilla), olive (Olea europaea), pomegranate (Punica granatum), Aloe vera, and black seed (Nigella sativa), along with their bioactive constituents, including flavonoids, tannins, and terpenoids. These compounds exhibit gastroprotective properties through multiple mechanisms, such as enhancing the gastric mucosal barrier, inhibiting acid secretion, displaying antioxidant and anti‐inflammatory effects, promoting ulcer healing, and combating Helicobacter pylori infection. The evidence presented includes in vitro assays, animal models, and some clinical studies. While many of the 53 plants reviewed demonstrated significant anti‐ulcer effects compared to standard drugs, further clinical research is needed to establish efficacy and safety in humans. The synergistic actions of phytochemical mixtures in medicinal plant extracts likely contribute to their therapeutic potential. This review highlights the role these North African medicinal plants may play in the prevention and treatment of peptic ulcers and identifies promising candidates for further research and development of evidence‐based botanical therapies.

Genome-Wide Identification and Expression Analysis of the REF Genes in 17 Species

Natural rubber production currently relies heavily on a single species, Hevea brasiliensis, underscoring the urgent need to identify alternative sources to alleviate the strain on natural rubber production. The rubber elongation factor (REF) and small rubber particle protein (SRPP), both members of the REF/SRPP gene family, are crucial for natural rubber biosynthesis. However, research on the REF gene has predominantly focused on H. brasiliensis and Taraxacum kok-saghyz. We conducted a comprehensive genome-wide identification and characterization of the REF gene, identifying 87 REF protein sequences across 17 plants species. We observed a significant increase in the copy numbers and expression of REF genes in rubber-producing plants. Notably, in H. brasiliensis, T. kok-saghyz, Eucommia ulmoides, Lactuca sativa, and other rubber-yielding species, the number of REF genes has markedly increased. Furthermore, some REF genes in H. brasiliensis form a distinct clade in phylogenetic analyses and exhibit differences in conserved motif arrangements and tertiary protein structures compared to other REF genes. These findings suggest that REF genes in rubber-producing plants may have undergone independent evolution, leading to changes in copy number and structure. These alterations could contribute to the production of natural rubber in these species. The results of this study provide a scientific basis for further research into the mechanisms of rubber production in plants and for identifying potential rubber-producing species.

Nanomaterial-Based Biofortification: Potential Benefits and Impacts of Crops.

Nanomaterials (NMs) have shown relevant impacts in crop protection, improvement of yields, and minimizing collateral side effects of fertilizer and pesticides in vegetable and fruit production. The application of NMs to improve biofortification has gained much attention in the last five years, offering a hopeful and optimistic outlook. Thus, we propose comprehensively revising the scientific literature about the use of NMs in the agronomic biofortification of crops and analyzing the beneficial impact of the use of NMs. The results indicated that different species of plants were biofortified with essential elements and macronutrients after the applications of Zn, Fe, Se, nanocomposites, and metalloid NPs. In addition, the physiological performances, antioxidant compounds, and yields were improved with NMs. Using nanofertilizers for the biofortification of crops can be considered a promising method to deliver micronutrients for plants with beneficial impacts on human health, the environment, and agriculture.

Harnessing the power of rhizosphere bacteria for pollution remediation: strategies, mechanisms, and environmental impact: A review

This review explores into the sizeable potential of rhizosphere bacteria as effective mediators in the pollution remediation. These rhizosphere bacteria are primarily found in the soil surrounding plant roots, and they have an extremely strong ability to remove a wide range of toxins from the environment. This is attuned with the idea of phytoremediation, which is the use of plants to clean adulterated soil or water. In addition to vigorous participation in bioremediation processes, their diverse activities include stimulating plant growth and serving as biocontrol agents against plant diseases. Their ability to gather, change, and restrain pollutants is one of their main advantages, especially when used in combination with phytoremediation techniques. To fully utilize these microorganisms, it is essential to understand the various bacterial strains and their complex biological pathways that influence their behavior. The diversity and richness of rhizosphere bacterial populations, significantly affected by different plant species and environmental factors, is a crucial area that requires further study. Grasping this heterogeneity is essential for adapting phytoremediation strategies to particular contamination situations and exploiting their effectiveness. Rhizosphere microorganisms present a feasible path towards a more supportable and clean future. This might potentially make a big contribution to environmental restoration efforts in a world that is always changing.

Segetal plants of agricultural landscapes of the Southern Non‐Chernozem zone as a source of biological resources

Aim. To identify economically significant species of segetal plants of agrophytocenoses in the Southern Non‐Chernozem zone and assess their dynamics with changes in anthropogenic load.The study was carried out by analysing geobotanical descriptions of agrophytocenoses in the Southern Non‐Chernozem Zone. The species diversity of economically important species was established during the period of extensive farming (1929–1933), the beginning of intensification (1936–1938), a high level of intensification (1981–1983), and a period of decreasing intensity of farming (2012–2022).At all stages of the study, groups of forage, medicinal and honey plants were round to have a high species diversity. The presence of individual representatives of vegetable, vitamin, insecticidal and ornamental species in agrophytocenoses was established.Changes in the nature and degree of anthropogenic pressure on agrophytocenoses has led to a significant transformation of species composition and abundance of representatives of economically significant groups. The smallest number of these was noted in the 1980s. Currently, species diversity has increased due to a decrease in the intensity of agriculture in the region.

Biochemical Changes and Germination Response of Indian Sandalwood (Santalum album L.) Seeds Subjected to Biopriming Techniques and Variable Post-priming Storage

Understanding of the storage behaviour of endangered plant species such as Indian Sandalwood, Santalum album L. is important for successful conservation. We tested biopriming method with five biopriming agents (e.g. Effective microorganisms; Plant growth promoting rhizobacteria (PGPR-I and PGPR-II); Pseudomonas fluorescens and Piriformospora indica) with four uniform durations of treatments viz. 2, 4, 6 and 8 days. Hydropriming was also performed with similar condition for comparison of seed performance. The study examined the biochemical changes that occur in Sandalwood seeds during different post-priming storage periods (0, 30, 60, 90 days) to assess the efficacy of biopriming techniques on seed germination and health. Biopriming with Pseudomonas fluorescens for eight days recorded the highest germination percentage (70.67%) and the highest germination rate index (0.84). Longer durations of PGPR-I and Piriformospora indica treatment (6-8 days) lowered the imbibition period and mean germination time while increasing the germination rate. After a post-priming storage period of 30 days, only EM and Pseudomonas fluorescens treated seeds germinated while all other treatments failed to germinate. Absence of germination in any biopriming group at 60 and 90 days storage period indicated that the sandal seeds deteriorated over extended storage period. The reduction in seed viability of sandal seeds was consequent to the changes in the biochemical characteristics and action of enzymes (α and β amylases) involved in seed food reserve depletion and loss in membrane integrity.

Endophytic bacteria in Camellia reticulata pedicels: isolation, screening and analysis of antagonistic activity against nectar yeasts

Camellia reticulata, an ancient plant species endemic to Yunnan Province, China, remains underexplored in terms of its endophytic bacterial communities. The plant tissue pedicel serves as the connection between the flower and the stem, not only delivers nutrients but also transmits metabolic substances from endophytic bacteria to the nectar during long-term microbial colonization and probably improves the antagonistic activity of nectar against yeast. Hence, 138 isolates of endophytic bacteria have been isolated in this study from the pedicels of 12- and 60-year-old C. reticulata. Comparative analysis revealed significantly higher density of endophytic bacteria in older trees. Among these isolates, 29 exhibited inhibitory effects against nectar yeasts. Most of the isolates displayed positive results for Gram staining, catalase reaction, gelatin liquefaction, and motility. Additionally, the isolates demonstrated the ability to utilize diverse substrates, such as glucose, nitrate, and starch. Based on 16S rRNA molecular biology analysis, these isolates were identified to be 11 different species of 6 genera, with the majority belonging to Bacillus genus. Notably, C1 isolate, identified as Bacillus spizizenii, exhibited strongest antagonistic effect against three yeasts, i.e., Metschnikowia reukaufii, Cryptococcus laurentii, and Rhodotorula glutinis, with minimum inhibitory concentration values below 250 μg/mL. Major metabolites of B. spizizenii were aminoglycosides, beta-lactams, and quinolones, which possess antimicrobial activities. Furthermore, KEGG enrichment pathways primarily included the synthesis of plant secondary metabolites, phenylpropanoids, amino acids, alkaloids, flavonoids, neomycin, kanamycin, and gentamicin. Therefore, antagonistic activity of B. spizizenii against yeasts could be attributed to these antibiotics. The findings highlight the diverse endophytic bacteria associated with C. reticulata, indicating their potential as a valuable resource of bioactive metabolites. Additionally, this study provides new insights into the role of endophytic bacteria of pedicels in enhancing nectar resistance against yeasts.

The intermorph breeding system is responsible for reproductive success in heterostylous Nyctanthes arbor‐tristis L.

AbstractHeterostyly is a specialized reproductive system associated with self‐ and intramorph incompatibility. It reinforces the intermorph breeding system in heterostylous plant species. However, distyly has not been comprehensively studied in Nyctanthes arbor‐tristis. The present study demonstrates the floral traits, breeding system, fruit and seed set, and morph ratio in distylous N. arbor‐tristis. The length of style and filament showed reciprocal herkogamy between long style (L‐morph) and short style (S‐morph). Flower size, corolla tube size, stamen and anther length, ovary length, and pollen diameter were larger in S‐morph. However, the style was longer in L‐morph. Our results demonstrated strongly incompatible self‐ and intramorph pollination combinations. The intermorph pollination was compatible, showing normal pollen tube growth throughout the style and ovary. The embryo formation was also higher in intermorph interaction. Moreover, the fruit setting was higher when the intermorph plants grew in the vicinity of natural conditions. Collectively, all data indicate that N. arbor‐tristis is a distylous species with a self‐incompatible breeding system, resulting in less seed formation in nature.