Leaf venation networks evolved along several functional axes, including resource transport, damage resistance, mechanical strength, and construction cost. Because functions may depend on architectural features at different scales, network architecture may vary across spatial scales to satisfy functional tradeoffs. We develop a framework for quantifying network architecture with multiscale statistics describing elongation ratios, circularity ratios, vein density, and minimum spanning tree ratios. We quantify vein networks for leaves of 260 southeast Asian tree species in samples of up to 2 cm2 , pairing multiscale statistics with traits representing axes of resource transport, damage resistance, mechanical strength, and cost. We show that these multiscale statistics clearly differentiate species' architecture and delineate a phenotype space that shifts at larger scales; functional linkages vary with scale and are weak, with vein density, minimum spanning tree ratio, and circularity ratio linked to mechanical strength (measured by force to punch) and elongation ratio and circularity ratio linked to damage resistance (measured by tannins); and phylogenetic conservatism of network architecture is low but scale-dependent. This work provides tools to quantify the function and evolution of venation networks. Future studies including primary and secondary veins may uncover additional insights.
In this paper, we present a new method to recognise the leaf type and identify plant species using phenetic parts of the leaf; lobes, apex and base detection. Most of the research in this area focuses on the popular features such as the shape, colour, vein, and texture, which consumes large amounts of computational processing and are not efficient, especially in the Acer database with a high complexity structure of the leaves. This paper is focused on phenetic parts of the leaf which increases accuracy. Detecting the local maxima and local minima are done based on Centroid Contour Distance for Every Boundary Point, using north and south region to recognise the apex and base. Digital morphology is used to measure the leaf shape and the leaf margin. Centroid Contour Gradient is presented to extract the curvature of leaf apex and base. We analyse 32 leaf images of tropical plants and evaluated with two different datasets, Flavia, and Acer. The best accuracy obtained is 94.76% and 82.6% respectively. Experimental results show the effectiveness of the proposed technique without considering the commonly used features with high computational cost.
Land surface temperature is predicted to increase by 0.2 °C per decade due to climate change, although with considerable regional variability, and heatwaves are predicted to increase markedly in the future. These changes will affect where crops can be grown in the future. Understanding the thermal limits of plant physiological functioning and how flexible such limits are is thus important. Here, we report on the measurements of a core foliar thermotolerance trait, T50, defined as the temperature at which the maximum quantum yield (Fv/Fm) of photosystem II declines by 50%, across nine different Malaysian Hevea brasiliensis clones. We explore the relative importance of interclonal versus intraclonal variation in T50 as well as its association with leaf and hydraulic traits. We find very low variation in T50 within individual clones (mean intraclonal coefficient of variation (CoV) of 1.26%) and little variation across clones (interclonal CoV of 2.1%). The interclonal variation in T50 was lower than for all other functional traits considered. The T50 was negatively related to leaf mass per area and leaf dry matter content, but it was not related to hydraulic traits such as embolism resistance (P50) or hydraulic safety margins (HSM50). The range of T50 observed (42.9-46.2 °C) is well above the current maximum air temperatures Tmax,obs (T50 - Tmax,obs >5.8 °C), suggesting that H. brasiliensis is likely thermally safe in this south-east Asian region of Malaysia.
Artemisia vulgaris L. belongs to Asteraceae, is a herbal plant that has various benefits in the medical field, so that its use in the medical field can be explored optimally, the plant must be thoroughly identified. This study aims to identify A. vulgaris both in terms of descriptive morpho-anatomy and DNA barcoding using BLAST and phylogenetic tree reconstruction. The morpho-anatomical character was observed on root, stem, and leaf. DNA barcoding analysis was carried out through amplification and alignment of the rbcL and matK genes. All studies were conducted on three samples from Taman Husada (Medicinal Plant Garden) Graha Famili Surabaya, Indonesia. The anatomical slide was prepared by the paraffin method. Morphological studies revealed that the leaves of A. vulgaris both on the lower-middle part and on the upper part of the stem have differences, especially in the character of the stipules, petioles, and incisions they have. Meanwhile, from the study of anatomy, A. vulgaris has an anomocytic type of stomata and its distribution is mostly on the ventral part of the leaves. Through the BLAST process and phylogenetic tree reconstruction, the plant sequences being studied are closely related to several species of the genus Artemisia as indicated by a percentage identity above 98% and branch proximity between taxa in the reconstructed phylogenetic tree.
Background: Recent evidence suggests that some flavonoid compounds obtained from crude methanol extract of mistletoe leaves ( Dendrophthoe pentandra L. Miq), also known as Benalu Duku (BD), have antimicrobial effects. Thus, the plant has the potential to eliminate viruses that may cause outbreaks in chicken farms. This study aimed to prove the in vitro ability of flavonoid compounds, namely quercetin-like compounds (QLCs), to eliminate field viruses, specifically the Newcastle disease virus (NDV). Methods: This research was performed in two stages. An in vitro test was used with a post-test of the control groups designed at a significance of 0.05. BD leaves (5 kg) were extracted using a maceration method with methanol and then separated into hexane, chloroform, ethyl acetate, and methanol fractions. The final extracted products were separated using semi-preparative high-performance liquid chromatography (HPLC) to obtain QLCs. The QLCs were identified and compared with quercetin using HPLC, proton and carbon nuclear magnetic resonance spectrometry, Fourier transform infrared spectrophotometry, and ultra-performance liquid chromatography-mass spectrometry. The activity of QLCs was tested in vitro against the NDV at a virulency titer of 10 -5 Tissue Culture Infectious Dose 50% (TCID50) and in chicken kidney cell culture. Results: Solutions of 0.05% (w/v) QLCs were discovered to have antiviral activity against NDVs, with an average cytopathogenic effect antigenicity at a 10 -5 dilution (p<0.05). Conclusions: QLCs from flavonoids from the leaves of BD have antiviral bioactivity against NDVs and may have the potential to be developed as medicinal compounds for the treatment of other human or animal viral infections.
Rattan is an important climbing palm taxon in Malaysian tropical rain forests. Many rattan species have unique structures directly associated with certain ant species. In this study, four rattan species (Daemonorops lewisiana, Calamus castaneus, Daemonorops geniculata and Korthalsia scortechinii) were inspected and documented in a field survey concerning their relationships with several ant species. We noticed that two rattan species (D. lewisiana and C. castaneus) were more likely to be associated with ants compared to their neighbouring rattan (Plectomia griffithii). However, D. lewisiana and C. castaneus did not directly provide shelters for ant colonies, but possessed unique structures: upward-pointing spines and funnel-shaped leaves, which are equipped to collect more litter than P. griffithii. To test our litter collecting hypothesis, we measured the inclination of spines from the stem. Our results showed the presence of ant colonies in the litter-collecting rattans (D. lewisiana and C. castaneus), which was significantly higher compared to a non-litter-collecting rattan (P. griffithii). We propose a complex and novel type of adaptation (litter-collection and provision of nesting materials) for rattans, which promotes interactions between the rattan and ants through the arrangements of leaves, leaflets, and spines. In return, the rattan may benefit from ants' services, such as protection, nutrient enhancement, and pollination.
Six varieties of Ficus deltoidea Jack (Moraceae) showed leaf morphological variations through quantitative measurement on different plant parts. There were significant differences among six varieties studied by plant parts. The varieties studied include var. deltoidea Corner, var. angustifolia (Miq.) Corner, var. trengganuensis Corner, var. bilobata Corner, var. intermedia Corner, and var. kunstleri (King) Corner. The upper, middle and lower plant parts showed morphological variations in terms of leaf length, leaf width, leaf area and petiole length. Qualitative parameters also showed trends in morphological variations in terms of leaf shape, leaf base, leaf apex and leaf attachment. However, some qualitative parameters were not the recommended parameters to differentiate among varieties. On the other hand, leaf heterophylly has occurred in F. deltoidea because foliage of the young plant was different from the mature plant. Leaf heterophylly was observed in leaf shape and leaf apex parameters, whereby leaves from the lower plant parts were different from the upper and middle parts. The heterophylly in leaf shape was detected in varieties angustifolia, bilobata, intermedia and trengganuensis, whilst six varieties of F. deltoidea showed leaf apex heterophylly
This study was conducted to examine the variabilities in the chronology of vegetative and reproductive development of weedy rice (Oryza spp.) in comparison with commercial varieties. Data at different growth stages of 14 weedy rice morphotypes and 4 commercial rice varieties were recorded and analysed. Plant height of all weedy rice morphotypes were observed to be significantly higher compared to the commercial varieties at every growth stages; increase in height was between 10-37 cm for weedy rice morphotype, for every 2 weeks. Initial tillering ability at 14 days after planting (DAP) was higher in weedy morphotypes, however all the commercial rice varieties produced significantly higher number of tillers throughout the rest of the vegetative phases. Correlation between plant height and tiller number detected that taller plants produce fewer tillers than shorter plants. Higher leaf area index (LAI) of all weedy morphotypes except PWR01 at early growth stages indicated the vigorous growth of the morphotypes. Weedy rice morphotypes showed a wide range of anthesis and maturity duration. Accessions from the same weedy rice morphotypes were more heterogeneous in the flowering, anthesis and maturity period than the commercial varieties. These traits enables identification of weedy rice morphotypes at their different growth stages in the field.
This study was designed to evaluate the phenolic content and antioxidant activity of ethanolic extracts from T. catappa leaves obtained by different intervals of sonication.
Nepenthes ampullaria is a unique carnivorous tropical pitcher plant with the detritivorous capability of sequestering nutrients from leaf litter apart from being insectivorous. The changes in the protein composition and protease activity of its pitcher fluids during the early opening of pitchers (D0 and D3C) were investigated via a proteomics approach and a controlled protein depletion experiment (D3L). A total of 193 proteins were identified. Common proteins such as pathogenesis-related protein, proteases (Nep [EC:3.4.23.12], SCP [EC:3.4.16.-]), peroxidase [EC:1.11.1.7], GDSL esterase/lipase [EC:3.1.1.-], and purple acid phosphatase [EC:3.1.3.2] were found in high abundance in the D0 pitchers and were replenished in D3L samples. This reflects their importance for biological processes upon pitcher opening. Meanwhile, prey-inducible chitinases [EC:3.2.1.14] were found in D0 but not in D3C and D3L samples, which suggests their degradation in the absence of prey. Protease activity assays demonstrated the replenishment of proteases in D3L with similar levels of proteolytic activities to that of D3C samples. This supports a feedback mechanism and signaling in the molecular regulation of endogenous protein secretion, turnover, and activity in Nepenthes pitcher fluids. Furthermore, we also discovered several new enzymes (XTH [EC:2.4.1.207], PAE [EC:3.1.1.98]) with possible functions in cell wall degradation that could contribute to the detritivory habit of N. ampullaria.
Populations of the Bornean gliding lizard, Draco cornutus, differ markedly in the colour of their gliding membranes. They also differ in local vegetation type (mangrove forest versus lowland rainforest) and consequently, the colour of falling leaves (red and brown/black in mangrove versus green, brown and black in rainforest). We show that the gliding membranes of these lizards closely match the colours of freshly fallen leaves in the local habitat as they appear to the visual system of birds (their probable predators). Furthermore, gliding membranes more closely resembled colours of local fallen leaves than standing foliage or fallen leaves in the other population's habitat. This suggests that the two populations have diverged in gliding membrane coloration to match the colours of their local falling leaves, and that mimicking falling leaves is an adaptation that functions to reduce predation by birds.
Pennywort (Centella asiatica) is a herbaceous vegetable that is usually served in the form of fresh-cut vegetables and consumed raw. Fresh-cut vegetables are in high demand as they offer convenience, have fresh-like quality and are potentially great for therapeutic applications. However, it could be the cause of foodborne outbreaks. Pulsed light is known as a decontamination method for minimally processed products. The aim of this study was to determine the influence of pulsed light in combination with acidic electrolysed water on the sensory, morphological changes and bioactive components in the leaves of pennywort during storage. A combination of soaking with acidic electrolysed water (AEW) at pH 2.5 and pulsed light (PL) treatment (1.5 J/cm2) was tested on the leaves of pennywort. After treatment, these leaves were refrigerated (4 ± 1 °C) for two weeks and evaluated on the basis of sensory acceptance, the visual appearance of the epidermal cell and bioactive compounds. In terms of sensorial properties, samples treated with the combined treatment were preferred over untreated samples. The combination of AEW and PL 1.5 J/cm2 was the most preferred in terms of purchasing and consumption criteria. Observations of the epidermal cells illustrated that PL treatment kept the cell structure intact. The bioactive phytocompounds found in the leaves of pennywort are mainly from the triterpene glycosides (asiaticoside, madecassoside, asiatic acid and madecassic acid) and are efficiently preserved by the combined treatment applied. In conclusion, the combination of acidic electrolysed water and pulsed light treatment is beneficial in retaining the sensory quality and bioactive compounds in the leaves of Pennywort during storage at 4 ± 1 °C.
Detecting cassava leaf disease is challenging because it is hard to identify diseases accurately through visual inspection. Even trained agricultural experts may struggle to diagnose the disease correctly which leads to potential misjudgements. Traditional methods to diagnose these diseases are time-consuming, prone to error, and require expert knowledge, making automated solutions highly preferred. This paper explores the application of advanced deep learning techniques to detect as well as classify cassava leaf diseases which includes EfficientNet models, DenseNet169, Xception, MobileNetV2, ResNet models, Vgg19, InceptionV3, and InceptionResNetV2. A dataset consisting of around 36,000 labelled images of cassava leaves, afflicted by diseases such as Cassava Brown Streak Disease, Cassava Mosaic Disease, Cassava Green Mottle, Cassava Bacterial Blight, and healthy leaves, was used to train these models. Further the images were pre-processed by converting them into grayscale, reducing noise using Gaussian filter, obtaining the region of interest using Otsu binarization, Distance transformation, as well as Watershed technique followed by employing contour-based feature selection to enhance model performance. Models, after fine-tuned with ADAM optimizer computed that among the tested models, the hybrid model (DenseNet169 + EfficientNetB0) had superior performance with classification accuracy of 89.94% while as EfficientNetB0 had the highest values of precision, recall, and F1score with 0.78 each. The novelty of the hybrid model lies in its ability to combine DenseNet169's feature reuse capability with EfficientNetB0's computational efficiency, resulting in improved accuracy and scalability. These results highlight the potential of deep learning for accurate and scalable cassava leaf disease diagnosis, laying the foundation for automated plant disease monitoring systems.
The current study aimed to explore the phytochemical composition of guava (Psidium guajava) leaves extract and to assess its antimicrobial activity. This was done by in vitro assays, such as agar well diffusion assay and minimum inhibitory concentration (MIC) and in vivo antimicrobial testing in broiler chickens experimentally infected with Salmonella gallinarum (SG). Phytochemical screening showed the presence of flavonoids, tannins, terpenoids, phenols, and saponins. The zone of inhibition (ZOI) of guava leaves extract against SG according to the agar well diffusion assay was concentration-dependent. MIC was found to be 6.25 mg/mL. In the case of the in vivo study, 150 day-old broiler chicks were obtained and separated into five groups (A, B, C, D, and E). Group A was the control group that was not infected. Group B (preventive) was treated with the extract on days 4, 5 and 6 and then inoculated with SG (3×108 CFU/mL) on day 7. Group C: SG was infected but untreated. On day 7, group D was inoculated with SG and once clinical symptoms were experienced, the extract of guava leaves was used on days 11, 12 and 13. On day 7, Group E was inoculated and on days 11, 12 and 13 the standard antibiotic ciprofloxacin was administered. Hematological and serum biochemical evaluations on days 7, 14, and 21 demonstrated that guava leaves extract exerted a potent antimicrobial effect against Salmonella gallinarum, with efficacy comparable to the standard antibiotic ciprofloxacin in the in vivo model. All treated groups had their severity of gross and histopathological changes reduced by guava leaves extract. It is interesting to note that the conventional antibiotic ciprofloxacin was less effective in in vitro and in vivo analyses. The conclusion was that guava leaves extract is a strong antimicrobial agent against Salmonella gallinarum in broiler chickens.
Papaya ringspot virus (PRSV) is a plant virus transmitted by aphids that has spread throughout many countries, including Malaysia, causing yield losses and economic impacts to the papaya industry worldwide. PRSV infection in papaya-distinctive ring-shaped patterns on papaya leaves resulted in stunted growth and reduced fruit quality. Management strategies such as the use of resistant varieties, cultural practices, and vector control are employed to mitigate the spread of PRSV. However, the evolution of new virus strains and the uncertainties posed by climate change pose ongoing challenges for the management of PRSV worldwide. Therefore, in this present study, we aim to confirm the presence of PRSV in symptomatic papaya leaves, to depict the current status of PRSV in Malaysia. Using reverse-transcription PCR (RT-PCR) targeting PRSV partial nuclear inclusion b protein (NIb) and coat protein (CP), 13 out of 40 papaya leaves collected were found positive for the PRSV strain-P (PRSV-P). Nucleotide analysis revealed a high similarity with strains from Taiwan and India, showing 96.83%, 97.03%, and 97.03% identity with the Taiwan strains (DQ340771, AY027810) and the India strain (KJ755852), respectively. Compared to the CP gene of Malaysian isolates reported in 2016 (EU082207), several nonsynonymous mutations have been discovered suggesting genetic diversity within the PRSV population in Malaysia. Overall, this study confirms the current circulation of PRSV infection in Malaysia since it was first identified in Johore in 1991. The re-occurrence of PRSV-P in this study highlights the need for continuous monitoring and targeted management strategies to prevent the further spread of PRSV-P in Malaysia.
Amorphophallus bufo is a rarely studied plant in Malaysian tropical rainforests. We measured the spectral reflectance of different developmental stages of A. bufo (seedlings, juveniles and adults), background soil/ debris and leaves from other neighboring plant species. Results show that the leaves of A. bufo seedling have a similar reflectance curve as the background soil and debris. Adults and juveniles of A. bufo are similar to other neighboring plants' leaf colors. We hypothesize that the cryptic coloration of A. bufo seedlings plays an important role in camouflage and that the numerous black spots on the surface of the petioles and rachises, may serve as a defensive mimicry against herbivores.
Anoectochilus sp. and Ludisia discolor are known as Jewel orchids. Both species are terrestrial wild orchids that grow in shaded areas of forests. The Jewel orchids are renowned for the beauty of their leaves, which are dark-green laced with silvery or golden veins. The orchids are used as a cure in various parts of Asia. Overharvesting and anthropogenic disturbances threaten the existence of the Jewel orchids in the wild, necessitating human intervention in their survival. An understanding of the structure and adaptations of a plant may assist in its survival when propagated outside of its habitat. In this study, ex vitro leaves of Anoectochilus sp. and L. discolor were subjected to freehand sectioning, and then inspected through brightfield and fluorescence microscopy. The study indicated that all parts of both plants presented typical monocotyledonous characteristics except the leaves. The leaves displayed dorsiventrality with distinct palisade and spongy mesophyll layers. The spongy mesophyll layer contained cells which fluoresced a bright red when exposed to ultraviolet, blue, and green light wavelengths, hinting at the presence of anthocyanins for photoprotection. Cyanidin was detected in the leaves of L. discolor, as enumerated through high performance liquid chromatography (HPLC). The observations indicated that Anoectochilus sp. and L. discolor are well-adapted to live under shaded conditions with minimal exposure to light.
Oil palm is grown in tropical soils with low bioavailability of Pi. A cDNA clone specifically expressed under phosphate-starvation condition in oil palm roots was identified as a high-affinity phosphate transporter (EgPHT1). The deduced amino acid sequence has 6 transmembrane domains each at the N- and C-termini separated by a hydrophilic linker. Comparison of promoter motifs within 1500 bp upstream of ATG of 10 promoters from high- and low-affinity phosphate transporter from both dicots and monocots including EgPHT1 was performed. The EgPHT1 promoter was fused to β-glucuronidase (GUS) reporter gene and its activity was analysed by histochemical and fluorometric GUS assays in transiently transformed oil palm tissues and T3 homozygous transgenic Arabidopsis plants. In response to Pi-starvation, no GUS activity was detected in oil palm leaves, but a strong inducible activity was observed in the roots (1.4 times higher than the CaMV35S promoter). GUS was specifically expressed in transgenic Arabidopsis roots under Pi deficiency and starvation of the other macronutrients (N and K) did not induce GUS activity. Eight motifs including ABRERATCAL (abscisic-acid responsive), RHERPATEXPA7 (root hair-specific), SURECOREATSULTR11 (sulfur-deficiency response), LTRECOREATCOR15 (temperature-stress response), MYB2CONSENSUSAT and ACGTATERD1 (water-stress response) as well as two novel motifs, 3 (TAAAAAAA) and 26 (TTTTATGT) identified through pattern discovery, occur at significantly higher frequency (p
Rattan spines are most often regarded as an identification trait and perhaps as a physical protection structure. In this study, we study the spinescence traits from five different species rattan: Daemonorops lewisiana, Daemonorops geniculata, Calamus castaneus, Plectomia griffithii, and Korthalsia scortechinii. We tested length, width, angle, strength, spine density, cross-section surface, spine color, and leaf trichomes (only for D. lewisiana, C. castaneus and D. geniculata). We also tested whether the spines were capable of deterring small climbing mammals (for Plectomia griffithii and Calamus castaneus) by using a choice selection experiment. Due to a variety of spine traits, we could not categorize whether any species is more or less spinescent than the others. We suggest that spines have a much more significant role than merely as a physical defense and work together with other rattan characteristics. This is also evidenced by our choice selection experiment, in which the spines on a single stem donot deter small climbing mammals. However, this is a work in progress, and we have outlined several alternative methods to be used in future work.