Plant Age Research Articles

Exploring the influences of resource limitation and plant aging on pollen development in Azorella nivalis Phil. (Apiaceae), a long‐lived high‐Andean cushion plant

Abstract Angiosperm pollen, the male gametophyte, plays a crucial role in facilitating fertilization by protecting and transporting male sperm cells to the female pistil. Despite their seemingly simple structure, pollen grains undergo intricate development to produce viable sperm cells capable of fertilizing the egg cell. Factors such as resource limitation and plant aging can disrupt normal pollen development and affect pollen performance. We investigated the influence of plant resources and aging on pollen developmental failure in Azorella nivalis Phil., an exceptionally long‐lived high‐Andean species that grows in a stressful alpine environment. Leveraging the modular nature of plants, we aimed to identify intra‐individual sources of variation in pollen developmental failure. By using pollen viability and variation in viable pollen grain size as indicators of pollen developmental performance, we assessed whether proxies of plant resource availability and aging influenced these pollen traits at the inter‐individual, inter‐flower and intra‐flower levels. Our findings revealed decreased pollen viability in putative resource‐depleted flowers and in shoots that experienced higher levels of meristematic divisions from the zygote (i.e., greater cell depth). Additionally, we observed increased variability in the size of viable pollen grains in resource‐depleted anthers. Our study suggests that resource availability and shoot aging are critical determinants shaping pollen development in long‐lived plants at the intra‐individual level. These findings contribute to our understanding of how differences in male fitness can arise in plants, with implications for their evolutionary trajectory.

Selection of Superior Clones of Cedrela odorata L. at Early Age in an Asexual Seed Orchard for Genetic Improvement

The selection of plant age in forest species is crucial in a genetic improvement program, as time is a key factor in decision-making. This study aimed to evaluate the variation in clonal growth of Cedrela odorata L. to identify clones with superior performance at an early age. The orchard was established in September 2014, utilizing a completely randomized block design with a planting distance of 4 x 4 m. The experiment comprised 70 clones (ortets), each with 35 replicates (ramets), totaling 2,450 ramets. Selection was based on four key traits: total height (th), clear stem height (csh), normal diameter (nd), and crown diameter (cd). These variables were used to calculate the percentage gain or loss in performance for each clone relative to the population mean. A principal component analysis, analysis of variance (ANOVA), Tukey test (p≤0.05), and cluster analysis were performed to assess the data. The results identified 16 out of the 70 clones as having superior traits. The superior clones included 53-CoSFcoChan07, 2-CoGua344, 15-CoB191, 19-CoKal126, 22-CoKal142, 41-CoTux558, 35-CoTez642, 56-CoTez539, 45-CoTez549, 49-CoTez540, 50-CoTez540, 59-CoTux555, 62-CoCar5, 30-CoBac02, 48-CoTez544, and 10-CoKal16. The average traits of these superior clones were 8.0±0.4 m for total height, 2.6±0.1 m for clear stem height, 0.13±0.0 m for normal diameter, and 4.1±0.2 m for crown diameter, representing a 15% increase over the population mean.

Analisis Faktor-Faktor yang Memengaruhi Pendapatan Petani Mangga (Mangifera indica L.) di Desa Sumberjaya Kecamatan Tempuran Kabupaten Karawang

Mango is one type of fruit that has high economic value and is popular in many countries, including Indonesia. According to data from BPS Karawang Regency, Tempuran District is one of the largest mango producers in Karawang Regency. The decline in mango fruit production in Tempuran Subdistrict is one of the problems in mango fruit cultivation which causes a lack of net income received by mango farmers. The purpose of this study is to determine the effect of land area, total production, selling price, labor, production costs, plant age and number of plants simultaneously and partially on the income of mango farmers. This research was conducted in Sumberjaya Village, Tempuran District, Karawang Regency. The research method used in this research is descriptive quantitative. The research data used are primary data and secondary data. Primary data used was obtained from interviews using a questionnaire. Secondary data used was obtained from books, journals, previous research reports and data from the Central Bureau of Statistics of Karawang Regency and related agencies. The sample was determined using the proportionate stratified random sampling method. The data analysis technique used was multiple linear regression analysis using SPSS 22. The results showed that the variables of land, amount of production, selling price, labor, production costs, plant age and number of plants had a significant influence simultaneously on the income of mango farmers. The variables of land, amount of production, and selling price partially have a significant positive effect. The variables of labor and production costs partially have a significant negative effect. The variables of plant age and number of plants partially do not have a significant influence on the income of mango farmers.

Assessing vertical seed dispersal through seed oxygen isotope ratios of Japanese larch (Larix kaempferi)

AbstractVertical seed dispersal, involving seed movement to higher or lower elevations, plays a vital role in plant adaptation to rising temperatures. However, its assessment has been limited owing to labor‐intensive processes. A recently developed method exploits the negative correlation between elevation and seed oxygen isotope ratios (18O/16O; hereafter δ18O) for efficient evaluation of vertical seed dispersal. Nevertheless, it remains unclear whether this method is suitable for conifers and whether plant size and age introduce noise into δ18O values, which would affect vertical seed dispersal estimations. In this study, we investigated the association between elevation and seed δ18O values of Japanese larch (Larix kaempferi) and explored the relationship among these oxygen isotope ratios, tree height, diameter at breast height (DBH), and age. Notably, we found a negative correlation between elevation and seed δ18O values of L. kaempferi but failed to detect any influence of tree height, DBH, and age on these oxygen isotope ratios. These findings suggest this method's potential for accurately estimating vertical seed dispersal across diverse plant lineages.

Impacts of groundwater depth and tree age on the non-structural carbohydrates of Haloxylon ammodendron

Nonstructural carbohydrates (NSCs) are important substrates for plant growth and metabolism, and their concentration reflects the plant's ability to adapt to environmental changes. Although the response of NSCs to changes in water availability has been extensively studied, it is still not fully understood whether this response is modulated by tree ages and organs. This study investigates Haloxylon ammodendron (C.A. Mey.) Bunge ex Fenzl, the dominant species in the Gurbantunggut Desert in the Uyghur Autonomous Region of China. Utilizing the natural topographic conditions characterized by a gradual increase in groundwater depth from the desert edge to the interior, we collected samples of different age classes of H. ammodendron along a groundwater depth gradient of 3, 7, 10, and 14 meters. We measured the total concentrations of non-structural carbohydrates (NSCs) and their components soluble sugar (SS) and starch (ST) in the assimilative twigs and stems. The results showed that the assimilative twigs of H. ammodendron exhibited higher NSC concentrations at the site with the deepest groundwater, while the other three sites showed similar NSC concentrations. Furthermore, as groundwater depth increased, the concentrations of SS in the assimilative twigs increased, whereas ST concentrations decreased. Similarly, the concentrations of SS in the stems also increased at sites with deeper groundwater. The NSC concentrations in the assimilative twigs were significantly affected by groundwater depth, while variations in stem NSC were primarily driven by plant age. In younger trees, higher soluble sugars concentrations in the stem may enhance water transport efficiency, whereas older trees tend to store more NSC to alleviate drought stress. Overall, elevated nonstructural carbohydrate concentrations contributed to greater drought resilience in H. ammodendron. These results suggest that different age classes of H. ammodendron exhibit distinct physiological responses to decreasing groundwater depth. The varying requirements for soluble sugars and starch in H. ammodendron help to partially mitigate the adverse effects of reduced groundwater accessibility. These findings provide important insights into the physiological adaptations of H. ammodendron in arid environments and offer a scientific basis for future ecological restoration and management strategies.

Effects of biological and environmental filtering on the community assembly of two grasslands in southern Mexico

AbstractQuestionsCommunity assembly is envisaged as filters that preclude some species in the regional pool from invading local communities. We tested whether the large floristic differences between adjacent calcicole and calcifuge grasslands are explained by either of five filters: environment (soil) or positive or negative interactions with plants and with soil biota.LocationSouthern Mexico.MethodsWe conducted a reciprocal‐transplant experiment with 20 species that were introduced to both habitats under three conditions: intact local community, without plants, and in sterilized plots. Each of the five filters mentioned above predict unique patterns in the performance (survival and growth) of plants in the six treatments. Thus, we used multimodel inference to determine which filters (patterns) were consistent with the evidence.ResultsWe detected at least one filter operating on all but four species. Survival data showed frequent support for environmental filtering, with interactions (mostly positive) playing a secondary role; however negative interactions became as frequent as environmental filtering when growth was considered.ConclusionsThe large physicochemical differences between the soils of both grasslands explain the high frequency of environmental filtering. Soils differed in nutrient availability, but also had toxic concentrations of different elements. Survival was strongly influenced by early mortality, while size was measured at the end of the experiment. It is thus likely that the differences between analyses based on survival and size reflect an ontogenetic change from positive to negative interactions. Other plants frequently facilitate seedlings, but this interaction often turns competitive over time. Soil mutualists provide nutrients that seedlings cannot access, but antagonists build up in the rhizosphere as plants age. Unlike studies that infer filters from extant plants in communities or from successful invasions, our approach provides direct evidence on which filters cause species to be absent from communities.

Elephant Grass Cultivar BRS Capiaçu as Sustainable Biomass for Energy Generation in the Amazon Biome of the Mato Grosso State

Sustainable biomasses are vital to ensure preservation of the Amazon biome within the Mato Grosso State whilst enabling energy generation for the region and its population. Here, the potential of the elephant grass cultivar BRS Capiaçu as an alternative to replace native forest wood as biomass for energy generation is investigated, considering the whole process from plant cultivation to biomass characterisation in terms of productivity of green and dry mass per hectare; density, moisture, ash, volatile and fixed carbon content, as well as higher heating value (HHV). MANOVA indicates that the effects of plant parts and age on density and proximate analysis parameters are influenced by the plant parts and age interaction, whereas HHV can be considered similar between them. The cultivar BRS Capiaçu showed suitable energetic values (17,922 < HHV < 18,918 kJ.kg−1) compared to that of native Amazon wood. Energetic results combined with cultivation outputs of high productivity (dry mass production of 44.1 tonnes.ha−1 at 180 days) with a short cutting interval (3 months), adaptation to the region’s climate and soil, and the possibility of cultivation in areas currently consolidated for agriculture demonstrate the potential of BRS Capiaçu as biomass to reduce native wood usage and deforestation rates.

Effects of Harvest Time and Acacia crassicarpa Age on the Physicochemical Characteristics of Apis mellifera L. Honey in Tropical Indonesian Forests

The comprehensive understanding of the physicochemical profile of monofloral honey derived from Acacia crassicarpa, specifically in the Indonesian tropical forest ecosystem, has not been fully explored. The physicochemical characteristics of honey significantly influence its quality and consumer acceptance. Harvest time and the age of Acacia plants, which are suspected to affect honey’s physicochemical properties, are this study’s focal points. Our objective is to analyze the impact of harvest time and Acacia age on the physicochemical characteristics of honey. Using a complete randomized block design, treatments were administered at 14, 21, and 30 days of harvest within three Acacia age groups: 3, 8, and 18 months. The honey composition was assessed following the Indonesian National Standard 8664:2018 procedure. The statistical analysis determined the optimal harvest period for honey by assessing its physicochemical properties and comparing them to the Indonesian National Standard 8664:2018 procedure (SNI 8664:2018 standards). One-way analysis of variance evaluated the effects of harvest time and plant age on composition, followed by a least significant difference tests to identify significant differences between harvest times. Results indicate a significant influence of harvest time and Acacia age on all honey composition variables, including diastase enzyme activity, hydroxymethylfurfural content, moisture level, sugar content, and acidity (P<0.01). Our findings suggest optimal honey harvest at 30 days, aligning with the 8th and 18th months of A. crassicarpa. Most variables met SNI 8664:2018 standards, except acidity levels. Further investigation is needed to discern the causes of acidity in Apis mellifera honey from Indonesian peat swamp forests.

Highest Occurring Vascular Plants from Ladakh Provide Wood Anatomical Evidence for a Thermal Limitation of Cell Wall Lignification.

As an evolutionary achievement of almost all terrestrial plants, lignin biosynthesis is essential for various mechanical and physiological processes. Possible effects of plant cell wall lignification on large-scale vegetation distribution are, however, not yet fully understood. Here, we present double-stained, wood anatomical stem measurements of 207 perennial herbs (Potentilla pamirica Wolf), which were collected between 5550 and 5850 m asl on the north-western Tibetan Plateau in Ladakh, India. We also measured changes in situ root zone and surface air temperatures along the sampling gradient and applied piecewise structural equation models to assess direct and indirect relationships between the age and size of plants, the degree of cell wall lignification in their stems, and the elevation at which they were growing. Based on the world's highest-occurring vascular plants, the Pamir Cinquefoils, we demonstrate that the amount of lignin in the secondary cell walls decreases significantly with increasing elevation (r = -0.73; p < 0.01). Since elevation is a proxy for temperature, our findings suggest a thermal constrain on lignin biosynthesis at the cold range limit of woody plant growth.

Kajian Beberapa Status Hara Pada Areal Replanting Tanaman Karet (Hevea brasiliensis) di Kebun Aek Nabara Utara Kecamatan Bilah Hulu

Rubber plants (Hevea brasiliensis) will experience a decrease in production as plants age and the nutrient content in the soil decreases. This study aims to find out the chemical properties of soil on plantations of rubber crops that are converted into palm and coconut crops. The research was conducted from Februari 2023 to Agustus 2024 at the palm coconut plantation of PTPN III Aek Nabara North Garden in Labuhanbatu district and analyzed in the Land Laboratory of the Faculty of Agriculture of the University of Northern Sumatra. The methods used are observation methods, field sampling, and analysis in the laboratory to obtain quantitative data. Observation parameters include soil pH, C-organic, Total Nitrogen, Available P, Cation Interchange Capacity, and Base Fulness. The results of the survey showed that the level of soil fertility at the site of the research was included in the low category. The main limiting factor that causes the low fertility of the soil is the low content of organic material in the soil. In order to improve the fertility status of the ground at the research site for further planting, it is necessary to make efforts such as irrigation and fertilization, as well as the addition of organic materials, to make the availability of nutrients for plants more affordable. Keywords: replanting area, rubber plants, conversion, soil fertility, quantitative data

Nursery production, acclimatization, and orchard transplantation of Argania spinosa: Evaluating the impact of costs and plant age

The depletion of the argan area over time underscores the importance of enhancing the quality of argan seedlings to support regeneration. Key factors such as seedling age and nursery techniques including shade, substrate, and container play a crucial role in improving seedling quality and ensuring successful transplantation. Our study assessed the impact of seedling age, shading, substrate composition, and container volume on argan seedling production during the nursery phase and their influence in the transplantation phase. The findings revealed 40% shade covering in 12- and 18-month-old seedlings exhibited the most growth potential, while unshaded compartments were suitable for 6-month-old seedlings. Substrates S1, S3 and S6 respectively, resulted in the highest quality seedlings overall, with S1 being the most effective for 6-month-old seedlings, and S3 and S6 showing more impact for 12- and 18-month-old seedlings. Furthermore, the use of larger containers contributed to the production of high-quality seedlings. Field results showed lower mortality rates across different seedling ages (3.1% to 9.3%) and revealed no significant difference among the combinations, except for seedlings produced under 40% shade, where the S3C3 combination followed by S1C2 in the 6-month nursery production period demonstrated the highest relative growth rate in shoot length. The relative growth rate in diameter reported its highest value in the S1C2 combination of 18-month and 6-month-old seedlings. A cost benefit analysis was carried out, which revealed that the cost-effective combination was S1C2, followed by S3C3 for 6-month-old nursery age under the 40% compartment.

Mitigating Salinity Stress in Cotton (Gossypium hirsutum L.) with K-humate and Iron Oxide Nanoparticles

Salinity stress poses a major challenge to plant growth and development, causing problems like osmotic stress, ion toxicity, and nutrient imbalances. These issues lead to reduced photosynthesis and early aging of plants. In this study, we explored the potential of potassium humate (Kh) and iron oxide nanoparticles (Fe (II,III) oxide-NPs) to help cotton plants (Gossypium hirsitum L.) cope with saline conditions. We examined various growth parameters such as plant height, leaf number, fresh and dry weights of leaves and roots, leaf area, chlorophyll content (SPAD values), and relative water content (RWC). Our findings showed that salinity stress significantly decreased plant height, leaf number, fresh leaf weight, dry leaf weight, leaf area, and RWC. However, the application of Fe (II,III) oxide-NPs and Kh helped mitigate these negative effects. Notably, the combination of Fe (II,III) oxide-NPs and Kh resulted in the highest plant height under saline conditions. Kh alone was particularly effective in increasing leaf number and fresh leaf weight, even under stress. In conclusion, both Fe (II,III) oxide NPs and Kh proved to be effective in enhancing cotton plant resilience to salinity stress, highlighting their potential use in sustainable agriculture in saline and arid regions. These insights can help develop strategies to improve plant growth and yield under challenging environmental conditions.

Unveiling Fusaria mycoflora associated with natural occurrence of lisianthus wilt and stem rot in Central-highland Vietnam.

Wilt and stem rot (WSR) is an emerging syndrome threatening cut lisianthus (Eustoma russellianum) production in Lam Dong province, Vietnam. The disease was observed in all 13 inspected commercial lisianthus greenhouses across major lisianthus cultivation areas in Lam Dong, including Da Lat, Lac Duong, Don Duong, and Duc Trong, with incidence increasing with plant age, ranging from 7.5 to 32.4%. Infected plants displayed stunting, wilting, stem rot and blight, and dieback, with predominance of wilt and stem rot. The disease showed polycyclic behavior, with symptoms shifting from random or scattered in young plants to clustered patterns after the initial flower cutting. Forty-one Fusaria-like fungal isolates recovered from diseased lisianthus plants were identified as Fusarium vanleeuwenii (28 isolates), Neocosmospora solani (11 isolates), and F. annulatum (2 isolates) based on morphological observations and phylogenetic analysis of the internal transcribed spacer (ITS) region and translation elongation factor 1-alpha (TEF-1α) genes. The composition of Fusaria species varied across sites, with F. vanleeuwenii being consistently present. Pathogenicity tests confirmed that isolates of F. vanleeuwenii Li-Fo9511, N. solani Li-Fs4311, and F. annulatum Li-Fp3051 caused typical stem rot in in-vitro assays. In-planta assays showed wilting in seedlings starting two weeks post-infection, with a remarkable increase in disease incidence and severity between five and six weeks, particularly for F. vanleeuwenii Li-Fo9511. The pathogens were re-isolated and morphologically confirmed, fulfilling Koch's postulates. This is the first report of F. vanleeuwenii, N. solani, and F. annulatum as pathogens of lisianthus WSR in Vietnam, highlighting the need for effective control strategies.

Morpho-Anatomical Variations in Sisymbrium irio L. Plants Raised from Seeds Treated with γ Radiation.

This study determines the effect of γ irradiation on seed germination, growth, and morpho-anatomical traits of the Sisymbrium irio L. (London rocket) plant. Seeds irradiated with 2.5, 5, 10, 15, and 20 kGy of γ radiation showed a reduced germination percentage (13.68-56.84%) with reference to the control, showing an inverse relationship with radiation dose. Observations recorded at preflowering, flowering, and postflowering stages of plant growth showed a significant (P < 0.05%) dose-dependent decline in many growth parameters, such as root length, shoot length, shoot dry weight, number of leaves, and pods per plant, due to the radiation effect. However, root dry weight, leaf length, leaf dry weight, number of branches, and number of flowers per plant increased at the lowest dose (2.5 kGy) and then declined steadily with the increasing level of radiation. Likewise, several anatomical features (length of fibers and vessel elements, diameter of vessel elements, proportion of cortex, and vasculature in the stem) showed a consistent decrease with increasing γ irradiation in treated plants compared with the control. However, the pith area and the number of vessels per microscopic field decreased significantly with the lowest radiation dose (2.5 kGy) and then increased gradually with higher doses at each ontogenetic stage. The vulnerability factor in the control as well as treated plants increased with increasing plant age. In treated plants, vulnerability was higher under the effect of low-level radiation than in the control, but it showed an inverse relationship with the increasing level of radiation, thus being the lowest at 20 kGy radiation dose. Mesomorphy also showed an almost similar variation pattern with reference to the radiation dose.

Analysis of plant physiological responses based on leaf color changes through the development and application of a wireless plant sensor

Optical sensing has been used to monitor the physiological responses of plants noninvasively and in real-time. In this study, we developed a low-cost plant sensor that performed a spectroscopic measurement at eight wavelengths in the visible region. The sensor head of the system was attached directly to the underside of the leaf, not blocking the light, and eliminating correction work because of the constant distance between the sensor head and the sample. The collected data was shared in the cloud via a network, thereby enabling remote monitoring. The characteristics of the plant sensor as a spectral photometer were validated, with major wavelengths also showing good correlations with those of a conventional spectrometer. The reflectance of 620 nm in this sensor detected plant aging indicator chlorophyll, and 550 nm detected stress indicator xanthophyll. In the field test, these plant physiological responses, seasonal leaf color changes and environmental stresses, were observed remotely. The results indicate that the novel spectroscopic measurement from the underside of the leaf is effective to realize accurate and stable measurement of the plant leaf. The plant sensor can be a powerful tool in the field of agriculture and ecological study by realizing simultaneous, multi-point and remote monitoring at a low cost.

Remotely Piloted Aircraft for Evaluating the Impact of Frost in Coffee Plants: Interactions between Plant Age and Topography

An accurate assessment of frost damage in coffee plantations can help develop effective agronomic practices to cope with extreme weather events. Remotely piloted aircrafts (RPA) have emerged as promising tools to evaluate the impacts caused by frost on coffee production. The objective was to evaluate the impact of frost on coffee plants, using vegetation indices, in plantations of different ages and areas of climatic risks. We evaluated two coffee plantations located in Brazil, aged one and two years on the date of frost occurrence. Multispectral images were collected by a remotely piloted aircraft, three days after the occurrence of frost in July 2021. The relationship between frost damage and these vegetation indices was estimated by Pearson’s correlation using simple and multiple linear regression. The results showed that variations in frost damage were observed based on planting age and topography conditions. The use of PRA was efficient in evaluating frost damage in both young and adult plants, indicating its potential and application in different situations. The vegetation index MSR and MCARI2 indices were effective in assessing damage in one-year-old coffee plantations, whereas the SAVI, MCARI1, and MCARI2 indices were more suitable for visualizing frost damage in two-year-old coffee plantations.

The Time Is Ripe: Olive Drupe Maturation Can Be Simply Evidenced by a Miniaturized, Portable and Easy-to-Use MicroNIR Green Sensor

The analytical study described in this work, based on NIR spectroscopy with a handheld device, allowed the development of a chemometric prediction model that has been validated for the objective evaluation of the ripening of olive drupes. The miniaturized, portable NIR spectrometer is proposed here as an easy-to-use sensor able to estimate the best harvesting time for ripening of olive drupes. The MicroNIR/chemometrics approach was developed for on-site identification of olive drupe ripening directly on plants, avoiding collection and successive laboratory analysis steps. A supporting parallel characterization by chromatographic techniques validated the spectroscopic prediction. The novelty of this approach consists in the possibility of investigating the olive drupe maturation point by collecting spectra in the near-infrared region and processing them using a chemometric model. The fast and accurate device allows one to easily follow the spectrum profile changes of olive drupes during ripening, thus preserving the fruits from being harvested too early or too late. The results of this study demonstrate the possibility of using the MicroNIR/chemometrics approach to determine the optimal ripening time of olives regardless of the plant variety, age and cultivation location. The results consequently demonstrated that the MicroNIR/chemometrics approach can be proposed as a new method to perform on-site evaluation of ripening by a single-click device. It can be conveniently used by any operator, who does not necessarily have to be expert but must simply be trained to use spectroscopy and a prediction model.

Impacts of paternal latitudinal origin on herbivore response strategies in Lythrum salicaria

Plants have evolved different strategies to withstand and respond to herbivore stress. The two main strategies plants employ under herbivore stress are known as tolerance and induced resistance. Tolerance is the ability to maintain high fitness despite experiencing high levels of herbivore damage. While induced resistance typically involves changing the concentrations of internal secondary metabolites as a response to initial herbivory and to prevent further damage. These strategies can lead to fitness differences between populations that vary by latitudinal origin. Previous studies have focused on the occurrence of herbivore response in general, whereas this study will make a direct comparison between response types and their fitness implications. Our study investigates whether eastern North American populations of Lythrum salicaria respond differently to herbivore stress. F1 crosses between L. salicaria individuals with different parental latitudinal ranges were grown in a common garden under two experimental herbivory treatments (pesticide sprayed vs. no pesticide) at the Queen’s University Biological Station. To identify differences in herbivore tolerance, we measured plant growth and development over 13 weeks and quantified herbivore damage, caused by the biocontrol beetle Galerucella calmariensis. A 48-hour feeding assay was then conducted to identify differences in herbivore resistance between populations. This assay provided beetles with a choice between young and old L. salicaria leaves from each experimental treatment. Our preliminary analysis of the feeding assay showed differences in leaf damage between parental lines. The initial analysis also showed that older leaves generally experienced more damage than younger leaves over the course of the 48-hour period. These results indicate population differences in herbivory stress response and differences in stress response effectiveness that varies with plant age. This experiment showed that L. salicaria individuals have varying degrees of herbivore stress response and effectiveness. However, further analysis that includes reproductive outputs and developmental differences will be completed to clearly identify the type of strategies L. salicaria populations with different parental latitudinal origins employ in response to herbivore damage.

Physiological Age of Stock Plants Determines Phytohormonal Changes in Leafy Cuttings of Prunus subhirtella 'Autumnalis'

AbstractThe aim of this study was to investigate adventitious root formation in cuttings obtained from physiologically different old stock material. The ornamental cherry Prunus subhirtella ´Autumnalis´ was used for the experiment. We examined three stock plants, namely a physiologically mature stock plant (about 60 years old) and physiologically juvenile plants (21 years old), which were previously propagated by cuttings, semi-mature stock material and in vitro juvenile stock material. We also investigated the role of phytohormones in the induction phase of adventitious root (AR) formation depending on the physiological age of the stock plant and the time after cutting. High performance liquid chromatography coupled with mass spectrometry (HPLC–MS/MS) was used to identify and quantify the phytohormones. The difference in rooting and quality of the developed AR is observed between semi-mature stock and mature stock material. Cuttings from semi-mature plants rooted in 95.00% of cases, while cuttings from mature stock plants only rooted in 68.33%. The high concentration of strigolactones and jasmonic acid (JA) immediately after severance had an inhibitory effect on the development of adventitious roots, especially in cuttings of mature origin. The development of AR is positively influenced by the increase in indole-3-acetic acid (IAA) 4 h after cutting from the stock plant. Our results show that the formation of adventitious root formation depends on the concentration and ratio between different phytohormones.

Evaluation of phytotoxic potential in Asteraceae plant extracts for biological control of Echinochloa crus-galli and Echinochloa colona.

This study evaluates the phytotoxic potential of methanolic extracts from six Asteraceae species: Wedelia chinensis, Helianthus annuus, Cosmos bipinnatus, Tagetes erecta, Tithonia diversifolia, and Zinnia elegans. The extracts were tested at concentrations of 0.03, 0.1, 0.3, and 1.0 g/mL to assess their inhibitory effects on the radicle and hypocotyl lengths of Echinochloa crus-galli and Echinochloa colona. The two most potent species, C. bipinnatus and T. diversifolia, were further evaluated using extracts from their roots, stems, and leaves. Among these, C. bipinnatus leaf extracts showed the most significant phytotoxicity and were tested at 20, 40, and 60 days of plant age. At 0.03 g/mL, C. bipinnatus extract inhibited the hypocotyl and radicle lengths of E. colona by 23.01% and 56.45%, and E. crus-galli by 8.5% and 36.35%, respectively. At 1.0 g/mL, the extract inhibited the hypocotyl lengths of E. colona and E. crus-galli by 97.54% and 88.15%, and the radicle lengths by 93.52% and 99.99%, respectively. The 60-day-old C. bipinnatus leaf extract exhibited the highest inhibitory effect, correlating with the identification of key allelochemicals such as cinnamic acid, caffeic acid, coumaric acid, ferulic acid, 2-4 dimethohydroxy benzoic acid, and salicylic acid. These findings suggest that the 60-day-old C. bipinnatus leaf extracts have strong potential for use in the biological control of these weed species, offering a promising avenue for the development of natural herbicides.