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Correctly estimating the maximum lifespan of plant species is a necessary component of demographic and life-history studies, which, in turn, are needed for understanding climatic impacts. Arboreal monocotyledons, which can grow to >30 m in height and >5 m in trunk perimeter, are difficult to age because they do not undergo seasonal dormancy; hence, their longevity has been estimated using various size-related methods. In this study, we tested radiocarbon (14C) dating with Accelerator Mass Spectrometry (AMS) as an additional tool for determining the age of two iconic monocotyledons: the Canary Island palm and the dragon tree. A total of 25 samples were collected from the basal stem of four palms and five dragon trees on Gran Canaria and Tenerife and then processed using the most advanced 14C-AMS analysis available. Calibration curves provided by the "IntCal group" were used to determine the oldest possible age of each sample, and 16 of them were found to be "modern", i.e., formed after the 1950s. Nine samples that were either collected from exterior, but lignified, palm tissues or from interior, and lignified, dragon tree tissues suggested ages > 300 years. Given the constant improvement of 14C-AMS tools, they can contribute to the further refinement of existing scientific knowledge on Macaronesian charismatic megaflora. [ABSTRACT FROM AUTHOR]

Premise: Life span varies greatly across plants, with some species being capable of extreme longevity. Yet even long‐lived individuals are susceptible to climatic events, fire, and other challenges. We examined rare mortality events and their causes in two long‐lived palmettos over four decades. Methods: We monitored the survival of the clonal Serenoa repens and non‐clonal, Florida‐endemic Sabal etonia from 1981 to 2022 in four habitats along an elevational gradient within the globally imperiled Florida scrub ecosystem. We considered several challenges to palmetto survival, including extreme fires, shading due to lack of fire, droughts, periods of high precipitation, and possible pathogens. Results: Survival of palmettos was remarkably high, and mortality was infrequent (Serenoa: cumulative, 5.7%; annualized, 0%–0.68%; Sabal: cumulative, 3.5%; annualized, 0%–0.43%). Mortality was highest in higher‐elevation habitats with greater soil drainage, and smaller palmettos were more likely to die. When subjected to extreme fire, Serenoa suffered greater mortality than Sabal. Mortality in long‐unburned habitats with increased shading rivaled that which occurred with extreme fire. There was no evidence of mortality due to lethal bronzing palm disease. Conclusions: Both palmettos had exceptionally low mortality rates, which, coupled with earlier work showing slow rates of transition from seedling to adult and remarkable adult longevity, suggest notably low rates of population turnover. Observed mortality in long‐unburned habitats suggests the importance of fire‐management planning with prescription burning. Lengthy age to reproduction and/or dependency on clonal propagation limits migration or genetic adaptation to altered conditions caused by climate change. [ABSTRACT FROM AUTHOR]

Correctly estimating the maximum lifespan of plant species is a necessary component of demographic and life-history studies, which, in turn, are needed for understanding climatic impacts. Arboreal monocotyledons, which can grow to >30 m in height and >5 m in trunk perimeter, are difficult to age because they do not undergo seasonal dormancy; hence, their longevity has been estimated using various size-related methods. In this study, we tested radiocarbon (14C) dating with Accelerator Mass Spectrometry (AMS) as an additional tool for determining the age of two iconic monocotyledons: the Canary Island palm and the dragon tree. A total of 25 samples were collected from the basal stem of four palms and five dragon trees on Gran Canaria and Tenerife and then processed using the most advanced 14C-AMS analysis available. Calibration curves provided by the “IntCal group” were used to determine the oldest possible age of each sample, and 16 of them were found to be “modern”, i.e., formed after the 1950s. Nine samples that were either collected from exterior, but lignified, palm tissues or from interior, and lignified, dragon tree tissues suggested ages > 300 years. Given the constant improvement of 14C-AMS tools, they can contribute to the further refinement of existing scientific knowledge on Macaronesian charismatic megaflora.

Identifying to what degree inherent characteristics of plant species and their variation in response to their environment regulate the temporal stability of plant populations is important to understand patterns of species coexistence and the stability of ecosystems. Longevity is a key characteristic of plant life history and an important component of demographic storage, but age is usually unknown for herbaceous species.In a 12‐year‐old biodiversity experiment (Jena Experiment) comprising 80 grassland communities with six levels of plant species richness (1, 2, 4, 8, 16 and 60 species) and four levels of functional groups richness (1, 2, 3 and 4 functional groups), we studied populations of 38 dicotyledonous forb species (N = 1,683 plant individuals). The sampled individuals represented three plant functional groups (legumes, small herbs and tall herbs) and two different growth forms (species with long‐lived primary roots and clonal species with rhizomes/stolons). We assessed the age of plant individuals by means of growth ring analysis and related the age of plant populations to their temporal stability in terms of peak biomass production.On average, plant species richness did not affect the mean age of the populations or the maximum age of individuals found in a population. Age of herbs with taproots increased and age of herbs with clonal growth decreased with increasing species richness, cancelling out each other when growth forms were analysed together. Mean population age was lowest for small herbs and highest for tall herbs, while legumes had an intermediate population age. Herbs with a taproot were on average older than herbs with a rhizome. Across all species‐richness levels, populations with older individuals were more stable in terms of biomass production over time.Synthesis. Our study shows for the first time across multiple species that the longevity of forbs is affected by the diversity of the surrounding plant community, and that plant longevity as an important component of demographic storage increases the temporal stability of populations of grassland forb species. [ABSTRACT FROM AUTHOR]

Monocarpic plants have a single reproductive phase, in which their longevity is developmentally programmed by molecular networks. In the reproductive phase of Arabidopsis thaliana, the inflorescence meristem (IM) maintains a central pool of stem cells and produces a limited number of flower primordia, which result in seed formation and the death of the whole plant. In this study, we observed morphological changes in the IM at cellular and intracellular resolutions until the end of the plant life cycle. We observed four biological events during the periods from 1 week after bolting (WAB) till the death of stem cells: (1) the gradual reduction in the size of the IM, (2) the dynamic vacuolation of IM cells, (3) the loss of the expression of the stem cell determinant WUSCHEL (WUS), and (4) the upregulation of the programmed cell death marker BIFUNCTIONAL NUCLEASE1 (BFN1) in association with the death of stem cells. These results indicate that the stem cell population gradually decreases in IM during plant aging and eventually is fully terminated. We further show that the expression of WUS became undetectable in IM at 3 WAB prior to the loss of CLAVATA3 (CLV3) expression at 5 WAB; CLV3 is a negative regulator of WUS. Moreover, clv3 plants showed delayed loss of WUS and lived 6 weeks longer compared with wild-type plants. These results indicated that the prolonged expression of CLV3 at 4–5 WAB may be a safeguard that inhibits the reactivation of WUS and promotes plant death. Finally, through transcriptome analysis, we determined that reactive oxygen species (ROS) are involved in the control of plant longevity. Our work presents a morphological and physiological framework for the regulation of plant longevity in Arabidopsis.

Monocarpic plants have a single reproductive phase, in which their longevity is developmentally programmed by molecular networks. In the reproductive phase of Arabidopsis thaliana , the inflorescence meristem (IM) maintains a central pool of stem cells and produces a limited number of flower primordia, which result in seed formation and the death of the whole plant. In this study, we observed morphological changes in the IM at cellular and intracellular resolutions until the end of the plant life cycle. We observed four biological events during the periods from 1 week after bolting (WAB) till the death of stem cells: (1) the gradual reduction in the size of the IM, (2) the dynamic vacuolation of IM cells, (3) the loss of the expression of the stem cell determinant WUSCHEL (WUS), and (4) the upregulation of the programmed cell death marker BIFUNCTIONAL NUCLEASE1 (BFN1) in association with the death of stem cells. These results indicate that the stem cell population gradually decreases in IM during plant aging and eventually is fully terminated. We further show that the expression of WUS became undetectable in IM at 3 WAB prior to the loss of CLAVATA3 (CLV3) expression at 5 WAB; CLV3 is a negative regulator of WUS. Moreover, clv3 plants showed delayed loss of WUS and lived 6 weeks longer compared with wild-type plants. These results indicated that the prolonged expression of CLV3 at 4–5 WAB may be a safeguard that inhibits the reactivation of WUS and promotes plant death. Finally, through transcriptome analysis, we determined that reactive oxygen species (ROS) are involved in the control of plant longevity. Our work presents a morphological and physiological framework for the regulation of plant longevity in Arabidopsis. [ABSTRACT FROM AUTHOR]

Copyright of Bioscience Journal is the property of Bioscience Journal and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Objective: To characterize morphological and reproductive aspects of Chascolytrum subaristatum (Lam.) Desv., in the Entre Ríos province, Argentina. Materials and Methods: A comparative analysis was carried out of two observation periods, in which the inflorescences and seeds of Ch. Subaristatum were attended. In March, 2016, caryopses collected the previous year were planted. At the beginning of spring, 10 plants were evaluated during 2016 and 2017. he beginning of flowering, maturity and harvest moment, number of inflorescences, nodes and paracladia, and number of spikelets, were recorded. In addition, the weight, moisture and germination of anthecia with caryopses, were determined. The results between harvests, relative to the number of nodes and anthecia, were compared through the mean difference test for independent samples. The chi square test was applied for the homogeneity of proportions. Results: The structural morphology of the inflorescence in both years showed low variability. The percentage of inflorescences increased 37 % in the second year with regards to the first. The results of weight, moisture and germination of the caryopses showed significant differences between the harvest years (p ≤ 0,05). Non-deep physiological dormancy was observed, which was overcome after dry storage. Conclusions: Regarding the relation of the inflorescence with the productive aspects, harvest and seed quality, to manage the grassland appropriately, and to avoid grazing at the moment of development of the reproductive tillers, is suggested. In the Entre Ríos region, seed production is possible, and varies according to the conformation of the inflorescence, plant age and harvest year. [ABSTRACT FROM AUTHOR]

Objective: To characterize morphological and reproductive aspects of Chascolytrum subaristatum (Lam.) Desv., in the Entre Ríos province, Argentina. Materials and Methods: A comparative analysis was carried out of two observation periods, in which the inflorescences and seeds of Ch. Subaristatum were attended. In March, 2016, caryopses collected the previous year were planted. At the beginning of spring, 10 plants were evaluated during 2016 and 2017. he beginning of flowering, maturity and harvest moment, number of inflorescences, nodes and paracladia, and number of spikelets, were recorded. In addition, the weight, moisture and germination of anthecia with caryopses, were determined. The results between harvests, relative to the number of nodes and anthecia, were compared through the mean difference test for independent samples. The chi square test was applied for the homogeneity of proportions. Results: The structural morphology of the inflorescence in both years showed low variability. The percentage of inflorescences increased 37 % in the second year with regards to the first. The results of weight, moisture and germination of the caryopses showed significant differences between the harvest years (p ≤ 0,05). Non-deep physiological dormancy was observed, which was overcome after dry storage. Conclusions: Regarding the relation of the inflorescence with the productive aspects, harvest and seed quality, to manage the grassland appropriately, and to avoid grazing at the moment of development of the reproductive tillers, is suggested. In the Entre Ríos region, seed production is possible, and varies according to the conformation of the inflorescence, plant age and harvest year. [ABSTRACT FROM AUTHOR]

This research was aimed at assessing the impact of different doses of nutrients on growth and flower quality of the Asiatic hybrid Lilium ((Lilium × elegans Thunb.) cv. 'Fangio') under the soilless culture. Five nutrient (fertigation) regimes were applied (T1: daily, T2: twice a week, T3: weekly, T4: twice a month and T5: control). Increasing the nutrient supply increased chlorophyll content index (SPAD, 45-93%), leaf area (30-55%), number of flowers per plant (25-67%) and substrate electrical conductivity (EC: 28-300%) compared to control. Although T3 (weekly nutrient supply) had lower shoot N, P, K+ and Ca+2 concentrations than T1, this regimen increased the number of flower buds by 20% and flower longevity by 56% compared to T1. Overall, weekly nutrient application is effective at maintaining flower quality and yield in the 'Fangio' lily, and compares favourably with programs in which fertigation is more frequent and the level of total applied nutrients is higher.

The ability of proteins to aggregate to form well-organized β-sheet rich amyloid fibrils is increasingly viewed as a general if regrettable property of the polypeptide chain. Aggregation leads to diseases such as amyloidosis and neurodegeneration in humans and various mammalian species but is also found in a functional variety in both animals and microbes. However, there are to our knowledge no reports of amyloid formation in plants. Plants are also the source of a large number of aggregation-inhibiting compounds. We reasoned that the two phenomena could be connected and that one of (many) preconditions for plant longevity is the ability to suppress unwanted protein aggregation. In support of this, we show that while protein extracts from the sugar maple tree Acer saccharum fibrillate readily on their own, this process is efficiently abolished by addition of small molecule extracts from the same plant. Further analysis of 44 plants showed a correlation between plant longevity and ability to inhibit protein aggregation. Extracts from the best performing plant, the sugar maple, were subjected to chromatographic fractionation, leading to the identification of a large number of compounds, many of which were shown to inhibit aggregation in vitro. One cautious interpretation is that it may have been advantageous for plants to maintain an efficient collection of aggregation-inhibiting metabolites as long as they do not impair metabolite function. From a practical perspective, our results indicate that long-lived plants may be particularly appropriate sources of new anti-aggregation compounds with therapeutic potential.

Biological seed coating is a new technique of seed treatment through which biological agents are coated over the seed surface for effective control of seed and soil-borne pathogens. In this study, pigeonpea seed was biologically coated with Pseudomonas fluorescens, Rhizobium spp. and Phosphorus solubilizing bacteria (PSB) using biofriendly polymer and sugar syrup as adjuvants. The shelf life of bioagents and seed quality parameters was studied during six months of storage period. The colony units of Pseudomonas increased with biofriendly polymer either as individual or in consortia with biofertilizers. Six months after treatment, more colony units of Pseudomonas fluorescens were recorded on the surface of biologically coated seed of pigeonpea with biofriendly polymer as an adjuvant compared to sugar syrup. Seeds coated with Pseudomonas and PSB using biofriendly polymer recorded high seed germination and seedling vigour compared to sugar syrup. The observations reveal that there is a possibility of coating seed with biological agents using biofriendly polymer immediately after processing or before packaging without affecting the shelf life of bioagents and seed quality. Thus, the biologically coated pigeonpea seed in advance of cropping season can go a long way in minimizing risk associated with on farm seed treatment. [ABSTRACT FROM AUTHOR]

Plant–disperser relationship is a mutual approach that regulates the species composition and habitat diversity. Here, we unfold the dispersal profile of India and provide comprehensive information on plant–disperser relationships, emphasising on plant longevities (annual, biennial, and perennial), plant life forms (tree, shrub, herb, liana), and vegetation types. The floral data were collected from a national database, and the dispersal information of 3301 geo-tagged plant species was gathered. The plant dispersal types were mainly (1) abiotic (hydrochory—water, anemochory—wind) and (2) biotic (endozoochory—internal gut, epizoochory—adherence to external surface, anthropochory—human, ornithochory—bird, myrmecochory—insect, and chirepterochory—bat) that included five dispersal modes, i.e. monochory (single), dichory (double), trichory (triple), quadrichory (four), and quintuchory (five). The generalised linear model was utilised to evaluate plant–disperser relationships. Monochory could explain variances of 56.8%, 51.2%, and 45.1% in perennials, annuals, and biennials, and 45.3%, 46.3%, 39.4%, and 47.7% for trees, shrubs, herbs, and lianas, respectively. Monochory has more significant influence on all major vegetation types, with at least 40% variance explanation. Anemochory, the dispersal by wind factor, was found to exercise by most plants. The life form wise analytics revealed inclination of multiple modes of dispersal for herbs with abiotic factors might be due to lighter weight, followed by trees with biotic dispersers could be owing to large size seeds. The same trend was reported from herb-dominant grassland where abiotic factors mostly contribute to dispersal, whereas the tree-dominant vegetation types exhibit dispersal primarily due to biotic means. This study provides a synoptic diagnosis to understand the dispersal profile of India, which has been an understudied domain. [ABSTRACT FROM AUTHOR]

Summary: Floral longevity is a critical component of floral display, yet there is a conspicuous paucity of empirical research on its evolution within species. Evolutionary models of floral longevity are grounded in resource allocation theory and propose that selection acts on heritable variation to optimize longevity in light of competing floral construction and maintenance costs. Key assumptions remain untested within wild species.We measured maximum floral longevity alongside protandry, flower size, flower number and flowering rate across families of the monocarpic herb Sabatia angularis grown under high and low resources. We evaluated genetic variation, plasticity and correlations between display traits, including fundamental resource–allocation trade‐offs and their interactions with resource availability.All display traits showed significant genetic variation. Resource availability influenced mean floral longevity and flower number, with genetic variation in these responses. Importantly, both floral longevity–flower number and flower number–size trade‐offs were significant and stronger under low resources.This study reinforces the application of resource allocation theory to floral display trait evolution. Our work highlights the context‐dependency of trade‐offs and the potential importance of plasticity in resource allocation, with plants investing in the construction of new flowers at faster rates when resources are high rather than in the maintenance of longer‐lived flowers. [ABSTRACT FROM AUTHOR]

The ability of proteins to aggregate to form well-organized β-sheet rich amyloid fibrils is increasingly viewed as a general if regrettable property of the polypeptide chain. Aggregation leads to diseases such as amyloidosis and neurodegeneration in humans and various mammalian species but is also found in a functional variety in both animals and microbes. However, there are to our knowledge no reports of amyloid formation in plants. Plants are also the source of a large number of aggregation-inhibiting compounds. We reasoned that the two phenomena could be connected and that one of (many) preconditions for plant longevity is the ability to suppress unwanted protein aggregation. In support of this, we show that while protein extracts from the sugar maple tree Acer saccharum fibrillate readily on their own, this process is efficiently abolished by addition of small molecule extracts from the same plant. Further analysis of 44 plants showed a correlation between plant longevity and ability to inhibit protein aggregation. Extracts from the best performing plant, the sugar maple, were subjected to chromatographic fractionation, leading to the identification of a large number of compounds, many of which were shown to inhibit aggregation in vitro. One cautious interpretation is that it may have been advantageous for plants to maintain an efficient collection of aggregation-inhibiting metabolites as long as they do not impair metabolite function. From a practical perspective, our results indicate that long-lived plants may be particularly appropriate sources of new anti-aggregation compounds with therapeutic potential. [ABSTRACT FROM AUTHOR]

The aim - to evaluate lifespan (full cycle) and ontogeny stage durations of nine alpine short-lived North- West Caucasus plants.Methods. For calculation we used a new method which was developed and suggested earlier by us. This method is based on a discrete ontogeny description and on the probability theory and random processes. The data on the monitoring of the marked individuals were collected during six years.Results. We found out that the lifespan of Anthyllis vulneraria is 2.6±0.3 years (hereinafter “±” is Standard error), Draba hispida – 4.5±0.3, Murbeckiella huetii – 4.6±1.1, Carum meifolium – 7.8±1.4, Eritrichium caucasicum – 9.1±1.4, Trifolium badium – 10.3±2.6, Sedum tenellum – 11±2.05, Androsace albana – 12.1±2.5, Minuartia recurva – 22.9±4.5. Also we demonstrated the matrix population models for studied plants, which show the probability of transition of individuals from one ontogeny stage to another in time interval (in our experiment – 1 year).Conclusion. Mortality of seedlings and juvenile plants, except Murbeckiella huetii, is around and more than 50%. Two years is the minimal amount of time that is necessary for full cycle of short-lived alpine plants, as it was shown for Anthyllis vulneraria, Murbeckiella huetii и Trifolium badium. A 3-12 years lifespan was calculated for other studied species. Persistence of Eritrichium caucasicum and Androsace albana populations provided by resistance of adult vegetative plants.

Correctly estimating the maximum lifespan of plant species is a necessary component of demographic and life-history studies, which, in turn, are needed for understanding climatic impacts. Arboreal monocotyledons, which can grow to >30 m in height and >5 m in trunk perimeter, are difficult to age because they do not undergo seasonal dormancy; hence, their longevity has been estimated using various size-related methods. In this study, we tested radiocarbon ( 14 C) dating with Accelerator Mass Spectrometry (AMS) as an additional tool for determining the age of two iconic monocotyledons: the Canary Island palm and the dragon tree. A total of 25 samples were collected from the basal stem of four palms and five dragon trees on Gran Canaria and Tenerife and then processed using the most advanced 14 C-AMS analysis available. Calibration curves provided by the "IntCal group" were used to determine the oldest possible age of each sample, and 16 of them were found to be "modern", i.e., formed after the 1950s. Nine samples that were either collected from exterior, but lignified, palm tissues or from interior, and lignified, dragon tree tissues suggested ages > 300 years. Given the constant improvement of 14 C-AMS tools, they can contribute to the further refinement of existing scientific knowledge on Macaronesian charismatic megaflora.

The article shares ways on how to appreciate the wonder of ancient trees and landscapes. Topics mentioned include the use of speculating noticing while traveling to learn the relations between plants and soils, a description of the ancient tree stump, and the importance of the care of farmers in the survival and longevity of trees.

The article offers insights into the status of urban forest in Calgary, Alberta. Topics mentioned include the city's total number of trees on private and public lands, total public assets of urban forests located in parks and green spaces, the key factors that may contribute to tree survival and longevity, the tree species diversity, and the role of community engagement and educational campaigns about trees in the growth of urban canopy.

Abstract: Domestication of desert‐adapted perennials has been proposed as an alternative to increase cropping intensity in low input environments. However, selection for high yield in perennial crops provokes indirect changes in plant resource use. These changes might alter how nitrogen is acquired, allocated, used and stored, thus affecting plant longevity and yield stability. Using the perennial forb Physaria as a model, we compared the pattern of N allocation, use and conservation of high‐yield accessions (Y), and stable yield accessions (S), with their wild counterpart (W). We found a negative relationship between seed yield and N conservation capacity and their associated traits. The shift of strategy provoked by high yield selection implies changes in N allocation and a decrease in nitrogen use efficiency and conservation capacity at plant‐ and leaf‐level. S accessions also increase allocation to seeds, although they kept the N use and conservation traits of their wild counterparts, remaining in an intermediate position between the Y and W accessions profiles. The shift of strategy provoked by high yield selection implies a decrease in nitrogen use efficiency and conservation capacity that may be behind the loss of longevity and yield on subsequent years. Wild and stable accessions were more conservative and show traits that promote nitrogen conservation. These are key traits that should not be lost during the selection process if breeders want to achieve the adequate ideotype of perennial crop for arid systems. [ABSTRACT FROM AUTHOR]

An experiment was conducted to study the effect of different concentrations of silver thiosulphate (STS) on flower longevity of Clarkia pulchella Pursh. The buds were subjected to 0.1, 0.25, 0.5, 0.75 and 1 mM of STS for 1 h pulse treatment. A separate set of flowers kept in distilled water was designated the control group. STS treatment resulted in improved flower longevity besides maintaining higher fresh and dry mass, water content and floral diameter. Conversely, total phenols, lipid peroxidation and lipoxygenase (LOX) activity decreased. The flowers treated with STS showed a significant increase in the activity of antioxidant enzymes such as superoxide dismutase (SOD), catalase (CAT) and ascorbate peroxidase (APX). Amongst various grades used, 0.5 mM STS was found to be most effective in enhancing the flower longevity by 1.5 days. The present study reveals that STS maintains lower LOX activity, thereby increased membrane stability index by improving the activity of antioxidant enzymes. [ABSTRACT FROM AUTHOR]

The aim of this study was to evaluate some biological activities of tomato as well as lycopene and to consider a new nutraceutic value for this fruit regarding to the protection against genetic damage and as a chemopreventive agent. Genotoxicity, DNA‐protection against hydrogen peroxide, and lifespan properties of tomato and lycopene were assessed through wing spot test and longevity assay using the Drosophila in vivo model. Additionally, chemopreventive activity was investigated through cytotoxicity, DNA‐fragmentation comet and annexin V FITC/PI assays using HL60 in vitro model. Results showed that: (i) tomato and lycopene are not genotoxic and protect against H2O2‐induced damage; (ii) with respect to the lifespan, tomato and lycopene are harmless at the lowest concentration; (iii) tomato is cytotoxic in a dose‐dependent manner, but not lycopene; (iv) tomato and lycopene do not induce internucleosomal DNA‐fragmentation although they induce significant clastogenic activity at low level in the leukemia cells. To sum up, tomato is a good candidate to be considered as a nutraceutical substance. Furthermore, synergistic action among other components within tomato matrix could be the cause of the health effects observed in this vegetable, which are not fully explained by lycopene. Environ. Mol. Mutagen. 59:427–437, 2018. © 2018 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]

Copyright of Canadian Journal of Plant Science is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Background and Aims Pollen grains of flowering plants display a fascinating diversity of forms, including diverse patterns of apertures, the specialized areas on the pollen surface that commonly serve as the sites of pollen tube initiation and, therefore, might play a key role in reproduction. Although many aperture patterns exist in angiosperms, pollen with three apertures (triaperturate) constitutes the predominant pollen type found in eudicot species. The aim of this study was to explore whether having three apertures provides selective advantages over other aperture patterns in terms of pollen survival, germination and reproductive success, which could potentially explain the prevalence of triaperturate pollen among eudicots. Methods The in vivo pollen germination, pollen tube growth, longevity and competitive ability to sire seeds were compared among pollen grains of Arabidopsis thaliana with different aperture numbers. For this, an arabidopsis pollen aperture series was used, which included the triaperturate wild type, as well as mutants without an aperture (inaperturate) and with more than three apertures. Key Results Aperture number appears to influence pollen grain performance. In most germination and longevity experiments, the triaperturate and inaperturate pollen grains performed better than pollen with higher aperture numbers. In mixed pollinations, in which triaperturate and inaperturate pollen were forced to compete with each other, the triaperturate pollen outperformed the inaperturate pollen. Conclusions Triaperturate pollen grains might provide the best trade-off among various pollen performance traits, thus explaining the prevalence of this morphological trait in the eudicot clade. [ABSTRACT FROM AUTHOR]

Common lilac ( Syringa vulgaris L.) is a popular ornamental shrub which under natural conditions of the temperate zone blooms for ca three weeks in May. Forcing procedures may extend the flowering period to 6 months in autumn and winter. Temperatures required to begin the forcing cycle range from 37 °C in November to 16 °C in March. Forcing lilac at 15 °C in November is also effective but longer than in the standard method, used by most growers. This study compared vase life and certain senescence-related processes in cut flowers of common lilac harvested from shrubs flowering under different conditions, i.e. outdoors under ambient temperature, forced in a greenhouse under 37 °C (the standard method) or 15 °C (the alternative method), and held in water or two vase solutions containing either nanosilver (NS) or 8-hydroxiquinoline citrate (8-HQC) as biocides and supplemented with 2% sucrose. The highest influence on vase life of cut lilacs had growing conditions. The vase life of cut lilacs obtained by the alternative forcing method – regardless of a holding solution – was significantly higher than those obtained by the standard forcing or blooming naturally. The highest H 2 O 2 content and proteolytic activity were usually observed in flowers collected from stems held in water. MDA content varied depending on flowering conditions and holding solutions. Its relatively low content was observed in the alternatively forced lilacs held in both preservatives which also prolonged the vase life relative to water, decreased the H 2 O 2 content and delayed nuclei degradation in petals. The activity of chosen antioxidant enzymes varied depending on the flowering conditions and generally remained unaffected by the preservatives. The effects of nanosilver with sucrose on cut lilac senescence were comparable to the action of the standard preservative containing 8-HQC, therefore this solution may also be recommended as an efficient preservative delaying senescence and prolonging vase life of cut lilacs. [ABSTRACT FROM AUTHOR]

This research was aimed at assessing the impact of different doses of nutrients on growth and flower quality of the Asiatic hybrid Lilium ((Lilium x elegans Thunb.) cv. 'Fangio') under the soilless culture. Five nutrient (fertigation) regimes were applied (T1: daily, T2: twice a week, T3: weekly, T4: twice a month and T5: control). Increasing the nutrient supply increased chlorophyll content index (SPAD, 45-93%), leaf area (30-55%), number of flowers per plant (25-67%) and substrate electrical conductivity (EC: 28-300%) compared to control. Although T3 (weekly nutrient supply) had lower shoot N, P, K+ and Ca+2 concentrations than T1, this regimen increased the number of flower buds by 20% and flower longevity by 56% compared to T1. Overall, weekly nutrient application is effective at maintaining flower quality and yield in the 'Fangio' lily, and compares favourably with programs in which fertigation is more frequent and the level of total applied nutrients is higher. [ABSTRACT FROM AUTHOR]

Background: Soil seed banks play an important role in regeneration in many ecosystems and contribute to ecosystem resilience in disturbed environments. This is especially true for the Braziliancampo rupestre, a fire-prone ecosystem that harbours a large number of endangered endemic species. Aims: We aimed to determine the persistence in the soil seed bank, through the evaluation of thein situlongevity, of seeds from four species of Velloziaceae, an endemic-rich and dominant family in thecampo rupestrevegetation. Methods: Seeds of four sympatric and commonVelloziaspecies were collected and placed in bags, which were buried in their natural area of occurrence. The germination capacity of the buried seeds was regularly evaluated under controlled light and temperature conditions over a 5-year period. Results: Noin situestablishment was observed for any of the buried seeds. All species retained high germinability throughout the burial, except forV. glandulifera, whose germinability was reduced by 60%. The reduction in germinability ofV. glanduliferawas positively correlated with seed size and mass. Conclusions: Seeds of the studied species ofVelloziaare capable of persisting in soil over time while maintaining high germinability. Seed traits appear to be important for seed bank persistence. [ABSTRACT FROM PUBLISHER]

On-spot persistence, space occupancy, and recovery after damage are key plant functions largely understudied. Traits relevant to these functions are difficult to assess because of their relationships to plant modularity. We suggest that developing collection protocols for these traits is feasible and could facilitate their inclusion in global syntheses. [ABSTRACT FROM AUTHOR]

Pronounced strategy shifts along ontogeny have been observed in several tree species, mainly because of the trend to maximize growth during the seedling stage, which constitutes the most vulnerable part of the tree's life cycle. Our aim here was to analyze the ontogenetic changes in crown characteristics and light capture patterns in three Quercus species: the evergreens Quercus ilex and Quercus suber and the deciduous Quercus faginea co-occurring in a Mediterranean open woodland. The seedlings were distributed in the large clearings among the adults and received full sunlight. We constructed three-dimensional models of the aerial parts of seedlings and mature trees of the three species, using the YplantQMC program. Large differences between growth stages were observed for all variables. The seedlings exhibited smaller branch sizes and crown densities than those observed in the adult trees. Leaf angles to horizontal also tended to increase during ontogeny, whereas leaf dispersion and the observed distances between leaves tended to decrease. The amount of photosynthetic radiation absorbed per unit leaf area throughout the growing season was lower in adult specimens than in young specimens. Changes in absorption efficiency during ontogeny were more intense for the species with longer leaf life span at maturity. We conclude that more intense ontogenetic shifts in species with longer leaf life span reflect the priority change from the maximization of short-term productivity at the seedling stage to maximizing leaf longevity during the adult stage. [ABSTRACT FROM AUTHOR]

Floral longevity (FL) determines the balance between pollination success and flower maintenance. While a longer floral duration enhances the ability of plants to attract pollinators, it can be detrimental if it negatively affects overall plant fitness. Longerlived leaves display a positive correlation with their dry mass per unit area, which influences leaf construction costs and physiological functions. However, little is known about the association among FL and floral dry mass per unit area (FMA) and water maintenance traits. We investigated whether increased FL might incur similar costs. Our assessment of 11 species of Paphiopedilum (slipper orchids) considered the impact of FMA and flower water-maintenance characteristics on FL. We found a positive relationship between FL and FMA. Floral longevity showed significant correlations with osmotic potential at the turgor loss and bulk modulus of elasticity but not with FA. Neither the size nor the mass per area was correlated between leaves and flowers, indicating that flower and leaf economic traits evolved independently. Therefore, our findings demonstrate a clear relationship between FL and the capacity to maintain water status in the flower. These economic constraints also indicate that extending the flower life span can have a high physiological cost in Paphiopedilum. [ABSTRACT FROM AUTHOR]

This work contributes to the understanding of plant cell responses to extreme water stress when it is applied at different intensity and duration. Fern spores are used to explore survival at relative humidity (RH) < 85% because their unicellular nature eliminates complexities that may arise in multicellular organisms from slower drying and variable responses of different cell types. Fern spore cytoplasm solidifies between 30 and 60% RH and spores survive this transition, but subsequently lose viability. We characterized the kinetics of viability loss in terms of the fluid to solid transition using concepts of water activity (i.e., sorption) and glass transition (Tg), two concepts that dominate studies of food and pharmaceutical stability. For all fern species studied, longest survival times were observed in spores placed at about 10–25% RH and mortality rates increased sharply above and below this moisture level. A RH of 10–25% corresponds well to sorption behavior parameters and is below the glass transition, measured using differential scanning calorimetry. Though response to RH was similar among species, the kinetics of deterioration varied considerably among species and this implies differences in the structure or mobility of molecules within the solidified cytoplasm. Our work suggests that desiccation damage occurs in desiccation tolerant cells, and that it is expressed as a time-dependent response, otherwise known as aging. [ABSTRACT FROM AUTHOR]

With increased drought events affecting forests globally, little is known about their future impact on Africa’s forests. In particular, we need to gain a better understanding of how key African forest species will respond to drought stress. In this study, we investigated functional traits and physiological responses to drought of the light-demanding pioneer species Maesopsis eminii Engl. The study involved an experiment on potted M. eminii seedlings with three different drought treatments in which sap flow (SF), stem diameter variation (SDV) and stomatal conductance (g s ) were measured. Whereas low g s rates (39 ± 30 mmol m −2 s −1 ) and pronounced SF-VPD (vapour pressure deficit) and g s -VPD hysteresis loops during well-watered conditions indicated conservative stomatal control on water loss, nocturnal sap flow implied M. eminii is not able to completely block transpiration. At the onset of drought, the pioneer seedlings retained high stem diameter growth despite highly reduced soil moisture (>−0.95 ± 0.03 MPa) and SF rates, indicating that growth was prioritised. Contribution of stored stem water to daily water use was limited both during drought and control conditions, which was confirmed by the absence of time lags between photosynthetic active radiation (PAR)-SDV, PAR-SF and SDV-SF in all treatments. Below a soil water potential of −0.95 ± 0.03 MPa, leaves were gradually shed, but diurnal and nocturnal SF did not turn zero, and absolute stem diameter kept decreasing for the entire experimental period (115 days), portraying that M. eminii seedlings can survive only limited drought periods. In sum, this study demonstrated that species-specific traits, as opposed to species ecological strategy, govern drought performance. For M. eminii , its leaf traits proved pivotal to its drought performance. [ABSTRACT FROM AUTHOR]

Tuberose cut flowers, available as loose flowers, were treated with gamma (γ) irradiation and generally regarded as safe (GRAS) preservative solutions for extension of shelf life. The flowers were packaged in low-density polyethylene bags, heat sealed and stored at 23 ± 2°C, 80% relative humidity (RH) and 4 ± 1°C, 40% RH, respectively. The flowers stored at these two temperature regimes were subjected to sensory evaluation and biochemical analyses. From these assessments, the longest shelf life of tuberose flowers was found to be 8 days at 23 ± 2°C, 80% RH (compared to 4 days for control) and 24 days at 4 ± 1°C, 40% RH (compared to 8 days for control) using combination treatment of low dose γ-irradiation (0.02 kGy) and preservative solutions (4% sucrose and 0.02% CaCl2). Ethanolic extract of tuberose flowers of the most shelf stable set (stored at 4 ± 1°C), i.e. at the end of 24 days, showed antimicrobial potency against the common skin pathogenStaphylococcus aureus(ATCC 25923 and MDR strains), suggesting utility of the senesced tuberose flowers for therapeutic applications. This preservation technique would promote export of tuberose flowers by extension of their shelf lives and allow utilization of these flowers, post senescence. [ABSTRACT FROM PUBLISHER]

Ethylene is one of many factors that affect the quality, appearance and longevity of miniature roses. In this study RT-PCR is used to compare the expression of ethylene biosynthetic genes and ethylene signal transduction genes at different stages of flower development in the two cultivars ‘Vanilla’ and ‘Lavender’, which show low and high ethylene-sensitivity, respectively, and their F1 offspring. The genes for the ethylene receptors RhETR1, RhETR2 and RhETR3, the genes for the receptor-associated signaling proteins RhCTR1 and RhCTR2, the genes for the transcription factors RhEIN3 and RhEIL, and the genes for the ACC synthases RhACS1 and RhACS2 each had an expression pattern that varied between the tested plants and tissues, but could not be correlated with the ethylene sensitivity of the plants. RhETR1, RhETR2 , RhETR3 and RhEIN3 were, e.g., expressed more in ‘Vanilla’ than in ‘Lavender’ in most, but not all, of the investigated tissues, but were in general not expressed more in progeny with low sensitivity than in progeny with high sensitivity. No expression was detected for the 4 other genes that were investigated, i.e. genes for RhETR4, RhACS3, RhACS4 and RhACS5. It is concluded that the precise transcriptional activities of the tested genes do not appear to be crucial in determining the ethylene sensitivity of miniature roses. It therefore appears likely that transcription of other genes involved in ethylene signal transduction, posttranscriptional or posttranslational control, or crosstalk with other signal transduction pathways may be important for the degree of ethylene sensitivity of miniature roses. [ABSTRACT FROM AUTHOR]

Vascular plants display a huge variety of longevity patterns, from a few weeks for several annual species up to thousands of years for some perennial species. Understanding how longevity variation is structured has long been considered a fundamental aspect of the life sciences in view of evolution, species distribution, and adaptation to diverse environments. Unlike animals, whose organs are typically formed during embryogenesis, vascular plants manage to extend their life by continuously producing new tissues and organs in apical and lateral directions via proliferation of stem cells located within specialized tissues called meristems. Stem cells are the main source of plant longevity. Variation in plant longevity is highly dependent on the activity and fate identity of stem cells. Multiple developmental factors determine how stem cells contribute to variation in plant longevity. In this review, we provide an overview of the genetic mechanisms, hormonal signaling, and environmental factors involved in controlling plant longevity through long-term maintenance of stem cell fate identity., (Copyright © 2023 The Author(s). Published by Elsevier Inc. All rights reserved.)

Photoperiod is an important factor influencing many biological processes including population dynamics of many insect species in temperate zones. To determine the population response of Chrysoperla nipponensis under altered conditions (high temperature and short photoperiod) and to test whether the short photoperiod was suitable for artificial storage, the life table data of C. nipponensis were collected at 25 ×C under a long photoperiod, 15:9h (L:D), and a short photoperiod, 9:15h (L:D) and analyzed using the age-stage, two-sex life table approach. We found that C. nipponensis developed faster under the long photoperiod than under the short photoperiod. The shorter developmental time, higher fecundity, and higher proportion of females found during the long photoperiod resulted in higher intrinsic and net reproductive rates, but a shorter mean generation time and life expectancy compared to those reared during the short photoperiod. Individuals reared under the short photoperiod also had a high reproductive value. Population projection demonstrated that C. nipponensis reared at the long photoperiod would complete four generations in 150 d, while reared under the short photoperiod would just be entering the second generation. Our results demonstrated that the different fitness values obtained for C. nipponensis individuals by varying photoperiod lengths, were readily distinguishable when using the age-stage, twosex life table. High winter temperatures would be detrimental to a diapausing population, and diapause induced by the short photoperiod would be beneficial to the storage of natural enemies. [ABSTRACT FROM AUTHOR]

Background and Aims Plasticity of floral traits in response to pollination can enable plants to maximize opportunities for pollen import and export under poor pollination conditions, while minimizing costs under favourable ones. Both floral longevity and display are key traits influencing pollination. While pollination-induced flower wilting is widely documented, we lack an understanding of the multifactorial complexity of this response, including the influence of other pollination components, costs of extended longevity and subsequent impacts on floral display. Methods Plasticity of floral longevity was experimentally evaluated in Sabatia angularis in response to multiple pollination factors: pollen addition, removal, and source (self, single-donor outcross, multiple-donor outcross) and timing of pollination. Effects of pollen quantity were further evaluated by exploiting variation in autonomous self-pollen deposition. Delayed pollination costs were tested comparing seed set from early versus late pollinations. Finally, I compared floral display metrics (peak floral display, time to peak flower, flowering duration, mean flowering rate) between experimentally pollinated and control plants. Key Results Floral longevity was highly plastic in response to pollen addition and its timing, and the response was dose-dependent but insensitive to pollen source. Pollen removal tended to extend floral longevity, but only insofar as it precluded pollination-induced wilting via autonomous self-pollination. Under delayed pollination, the wilting response was faster and no cost was detected. Pollination further led to reduced peak floral displays and condensed flowering periods. Conclusions Floral longevity and display plasticity could optimize fitness in S. angularis, a species prone to pollen limitation and high inbreeding depression. Under pollinator scarcity, extended floral longevities offer greater opportunities for pollen receipt and export at no cost to seed set, reproductive assurance via autonomous self-pollination and larger, more attractive floral displays. Under high pollinator availability, shortened longevities lead to smaller displays that should lower the risk of geitonogamy. [ABSTRACT FROM AUTHOR]

The aim of this study was to determine the effect of sous vide packaging on the shelf life of maple pea (Pisum sativum var. arvense L.) spread. Pea spreads were made of ground re-hydrated cooked maple peas 'Bruno' (Pisum sativum var. arvense L.), to which salt, citric acid, oil, and spices were added. Pea spread was stored in polyamide/polyethylene (PA/PE) film pouches, packaged in vacuum and hermetically sealed. Pea spread pouches were heat treated in a water bath, then rapidly cooled in ice-water and stored at 4.0 ± 0.5 °C. Sous vide was applied in three different heat regimens +(65.0; 80.0 and 100.0) ± 0.5 °C with cooking times 5, 10, 15, 20, 25, and 30 min at a constant temperature. Total plate count was determined according to ISO 4833-1:2014 on Plate Count Agar and Enterobacteriaceae determination was performed in accordance with ISO 21528-2:2004 on Violet Red Bile Glucose Agar. Total plate count in pea spread without thermal treatment was 3.41 log10 CFU g-1, in all sous vide packaged pea spread samples microbial contamination was significantly lower (p < 0.05). Enterobacteriaceae were not detected in any samples. It is possible to extend the shelf life of sous vide maple pea spread up to 14 weeks when stored at 4.0 ± 0.5 °C. [ABSTRACT FROM AUTHOR]

The consumption of fresh figs ( Ficus carica) has long been associated with longevity and health benefits. However, fresh figs are highly perishable. An alternative to extend the shelf life of this fruit might be the application of an edible film. Thus, in this study, fig fruits collected at two maturity stages (referred as stages III and IV) were coated with an alginate-chitosan bilayer edible (A-Ch BE) film and the main physiological and quality attributes were evaluated during storage at low temperature (6 °C) at 0, 3, 6, 9, 12, and 15 days of storage. Ethylene and CO productions were considered as physiological parameters, while firmness, color changes, weight loss, and visual infection were the quality attributes evaluated. The application of the film reduced CO production and increased ethylene emission, regardless of the maturity stage of the figs. Firmness for uncoated figs underwent a significant decrease during storage, exhibiting values lower than 1.0 N. On the contrary, for coated figs, firmness was not only maintained but also even increased up to 3 N, for figs of stage III, and up to 2.5 N for the more mature figs (stage IV). Furthermore, coated figs exhibited better external color retention (Δ E < 2), lower weight loss (∼8 %), and also lower visual fungal contamination (<5 %) than uncoated fruits during the 15 days of storage at 6 °C, regardless the maturity stage. Therefore, the results indicate that application of an A-Ch BE film not only can improve the overall quality of figs ( F. carica var. Mission) stored at 6 °C but is also able to extend their shelf life. [ABSTRACT FROM AUTHOR]

In each of two experiments, freshly harvested seeds of two cultivars of rice were dried and then rehydrated to different moisture levels. In experiment 1, seed equilibrium relative humidity (eRH) and moisture content (MC) were determined at each moisture level so that moisture desorption and adsorption isotherms could be constructed. Seed storage experiments were also carried out for seeds equilibrated at each moisture level, in sealed aluminium foil packets at 45°C. In experiment 2, storage experiments at 45°C were carried out on seeds dried to 12% MC and seeds dried to lower moisture levels and then rehydrated to 12% MC.The moisture adsorption isotherm was shifted to lower MC at a given eRH compared with the desorption isotherm. This hysteresis effect was seen both when seeds were dried to <6% MC and then allowed to adsorb moisture to different levels, and when seeds were dried to different levels (10, 8, 6 or 4% MC) and then allowed to adsorb moisture up to 12% MC. The log-log relationship between seed longevity, σ [the standard deviation of the normal distribution of seed deaths over time, as defined in the Ellis and Roberts (1980) seed viability equations] and seed storage MC did not vary depending on whether the seeds were desorbing or adsorbing moisture. The relationship between σ and eRH was better described by a log-log model than a log-linear model and did vary depending on whether seeds were desorbing or adsorbing moisture: at a given eRH, the longevity of adsorbing seeds was greater than that of desorbing seeds. The implications for seed storage are discussed. [ABSTRACT FROM AUTHOR]

Climate change will alter rainfall patterns. The effect of rainfall during seed development and maturation on wheat (Triticum aestivum L.) seed quality (ability to germinate normally; air-dry longevity in hermetic storage at 40°C with c. 15% moisture content) was investigated in field experiments (2011, 2012) by providing rain shelter or simulating additional rainfall. High ability to germinate was detected from mid seed filling until after harvest maturity. Subsequent longevity was more sensitive to stage of development. It increased progressively, reaching maximum values during maturation drying at 53–56 days after anthesis (DAA), 5–11 (2011) or 8–14 (2012) days beyond mass maturity; maximal values were maintained thereafter in 2011; longevity declined with further delay to harvest in 2012. Post-anthesis protection from rain had no major effect: in later harvests longevity was slightly greater than the control in each year, but in 2011 wetting treatments were also superior to the control. Wetting ears at all stages of development reduced longevity immediately, but considerable recovery in subsequent longevity occurred when seeds re-dried in planta for several days. The greatest damage to longevity from ear wetting occurred with treatments at about 56 DAA, with poorest recovery at 70 DAA (i.e. around harvest maturity) in absolute terms but at 56–70 DAA relative to gross damage. Hence, seed quality in a strongly dormant wheat variety was resilient to rain. Net damage was greatest from rain late in maturation. The phase of seed quality improvement in planta was dynamic with deterioration also occurring then, but with net improvement overall. [ABSTRACT FROM PUBLISHER]

An investigation was carried out with the postharvest mangoes (viz., the Langra and the Khirshapat) treating with different levels of Bavistin DF solution (namely, 250, 500, and 750 PPM ) for obtaining results on the reduction of postharvest losses, pattern of physical, biochemical changes as well as storability of postharvest mango. Data obtained from various biochemical analyses in terms of physicochemical properties and shelf life of postharvest mango, were recorded and statistically analyzed for comparison among the mean values using DMRT and LSD. The Khirshapat along with Bavistin DF at 750 PPM performed better in retardation of rapid augmentation of these compositions resulting in prolongation of shelf life. The Langra using 750 ppm of Bavistin DF was found to be excellent in lower diminishing tendency in terms of dry matter, ash, vitamin C followed by other treatment combination. [ABSTRACT FROM AUTHOR]

The tendency for flower longevity to increase with altitude is believed by many alpine ecologists to play an important role in compensating for low pollination rates at high altitudes due to cold and variable weather conditions. However, current studies documenting an altitudinal increase in flower longevity in the alpine habitat derive principally from studies on open-pollinated flowers where lower pollinator visitation rates at higher altitudes will tend to lead to flower senescence later in the life-span of a flower in comparison with lower altitudes, and thus could confound the real altitudinal pattern in a species´ potential flower longevity. In a two-year study we tested the hypothesis that a plastic effect of temperature on flower longevity could contribute to an altitudinal increase in potential flower longevity measured in pollinator-excluded flowers in high Andean Rhodolirium montanum Phil. (Amaryllidaceae). Using supplemental warming we investigated whether temperature around flowers plastically affects potential flower longevity. We determined tightly temperature-controlled potential flower longevity and flower height for natural populations on three alpine sites spread over an altitudinal transect from 2350 and 3075 m a.s.l. An experimental increase of 3.1°C around flowers significantly decreased flower longevity indicating a plastic response of flowers to temperature. Flower height in natural populations decreased significantly with altitude. Although temperature negatively affects flower longevity under experimental conditions, we found no evidence that temperature around flowers explains site variation in flower longevity over the altitudinal gradient. In a wetter year, despite a 3.5°C temperature difference around flowers at the extremes of the altitudinal range, flower longevity showed no increase with altitude. However, in a drier year, flower longevity increased significantly with altitude. The emerging picture suggests an increase in flower longevity along the altitudinal gradient is less common for potential flower longevity than for open-pollination flower longevity. Independently of any selection that may occur on potential longevity, plastic responses of flowers to environmental conditions are likely to contribute to altitudinal variation in flower longevity, especially in dry alpine areas. Such plastic responses could push flowers of alpine species towards shorter life-lengths under climate change, with uncertain consequences for successful pollination and plant fitness in a warming world. [ABSTRACT FROM AUTHOR]

NAD is a well-known co-enzyme that mediates hundreds of redox reactions and is the basis of various processes regulating cell responses to different environmental and developmental cues. The regulatory mechanism that determines the amount of cellular NAD and the rate of NAD metabolism remains unclear. We created Arabidopsis thaliana plants overexpressing the NAD synthase (NADS) gene that participates in the final step of NAD biosynthesis. NADS overexpression enhanced the activity of NAD biosynthesis but not the amounts of NAD+, NADH, NADP+ or NADPH. However, the amounts of some intermediates were elevated, suggesting that NAD metabolism increased. The NAD redox state was greatly facilitated by an imbalance between NAD generation and degradation in response to bolting. Metabolite profiling and transcriptional analysis revealed that the drastic modulation of NAD redox homeostasis increased tricarboxylic acid flux, causing the ectopic generation of reactive oxygen species. Vascular bundles suffered from oxidative stress, leading to a malfunction in amino acid and organic acid transportation that caused early wilting of the flower stalk and shortened plant longevity, probably due to malnutrition. We concluded that the mechanism regulating the balance between NAD synthesis and degradation is important in the systemic plant response to developmental cues during the growth-phase transition. [ABSTRACT FROM AUTHOR]

Mid- to very large-sized Douglas-fir ( Pseudotsuga menzieseii var. menziesii) that were lightly- to moderately-infected by dwarf mistletoe ( Arceuthobium douglasii ) were analyzed over a 14-year period to evaluate whether mechanical pruning could eradicate mistletoe (or at least delay the onset of severe infection) without significantly affecting tree vitality and by inference, longevity. Immediate and long-term pruning effects on mistletoe infection severity were assessed by comparing pruned trees ( n = 173) to unpruned trees ( n = 55) with respect to: (1) percentage of trees with no visible infections 14 years post-pruning, (2) Broom Volume Rating (BVR), and (3) rate of BVR increase 14 years post-pruning. Vitality/longevity (compared with unpruned trees) was assessed using six indicators: (1) tree survival, (2) the development of severe infections, (3) the development of dead tops, (4) tree-ring width indices, (5) Normalized Difference Vegetation Index (NDVI) from high-resolution multi-spectral imagery, and (6) live-crown ratio (LCR) and increment. Twenty-four percent of the pruned trees remained free of mistletoe 14 years post-pruning. Pruning is most likely to successfully eradicate mistletoe in lightly infected trees (BVR 1 or 2) without infected neighbors. Pruning significantly decreased mean BVR in the pruned versus the unpruned trees. However, the subsequent average rate of intensification (1.3–1.5 BVR per decade) was not affected, implying that a single pruning provides ∼14 years respite in the progression of infection levels. Post-pruning infection intensification was slower on dominant and co-dominants than on intermediate or suppressed trees. The success of mistletoe eradication via pruning and need for follow-up pruning should be evaluated no sooner than 14 years after pruning to allow for the development of detectable brooms. Based on six indicators, foliage from witches brooms contribute little to long-term tree vitality since removal appears to have little effect on resources available for tree growth and maintenance. In the severely pruned trees, tree-ring width was reduced for several years post-pruning, but then compensated with larger ring width in later years. Both NDVI and LCR increment were significantly higher for the pruned trees than the control trees, while the development of severe infections and/or dead tops was significantly (5× and 3×) higher for the controls. If possible, multiple indicators of tree vitality should be evaluated. Pruning can be worthwhile even if all the mistletoe is not removed, because mistletoe intensification is delayed. The impact of removing the brooms seems to be minimal, and post-pruning crowns had greater NDVI values. [ABSTRACT FROM AUTHOR]

The tacit assumption of functional ecology is that traits affect plant fitness. However, this link is mediated by demography, e.g. specific leaf area is not affecting changes in abundance directly but through vegetative multiplication or generative reproduction of plants − it means via demographic processes. We propose that in herbaceous perennials, architectural traits that capture shoot development constitute simple morphological surrogates of a number of demographic functions (shoot lifespan, lateral spread, multiplication rate). A shoot is a reiterated basic unit of a plant body in herbs and is easily recognizable as an individual. We propose that potential shoot lifespan (shoot cyclicity) may serve as a simple character relevant to demographic processes of clonal herbs while whole plant longevity plays a similar role for non-clonal herbs. Therefore we examined relationships of shoot and whole-plant lifespans with a key trait of the plant economic spectrum (specific leaf area, SLA) for a large set of Central European temperate zone herbs. We also investigated whether shoot and whole-plant lifespan are non-randomly distributed along environmental gradients, using indicator values and their distribution among plant community types. Finally, we analysed whether shoot cyclicity underlies differences in temporal turnover of plants in species-rich meadows. Our analyses showed that fast-growing species had shorter shoot and/or plant lifespan and preferred more productive environmental conditions, but the relationship was not strong. In addition, the two lifespan measures were independent of each other, indicating that shoot lifespan captures a rather different aspect of plant demography than whole-plant longevity. Turnover of perennial plants with annual shoots in meadow community was much higher than that of plants with long-lived shoots. Whole-plant and shoot lifespan constitute promising proxy variables for a mechanistic link between functional traits and community ecology in the temperate zone and deserves further attention. [ABSTRACT FROM AUTHOR]

The article highlights longevity experiments with common ragweed seeds in the soil seed bank from different origins in Germany, Slovenia, Hungary, Austria, and Denmark. Topics discussed include testing of the excavated seeds for viability by germination test, high variability in seed viability status of common ragweed samples, and steps in testing for viability of the buried common ragweed seeds.

The present experiment was conducted in the Department of Horticulture, Faculty of Agriculture, BAU, Kanke, Ranchi to study the effect of different media on rooting and survival of pear cuttings during the year 2014-15 under the chhotanagpur plateau region of Jharkand. It consisted of 15 treatments including control. All the treatments were replicated thrice in the experiment which was laid out in randomized block design. The media were soil (control), sand, FYM, leaf mould, vermicompost (each 100%), soil+sand, soil+FYM, soil+leaf mould, soil+vermicompost, sand+FYM, sand+leaf mould, sand+vermicompost, FYM+leaf mould, vermicompost+leaf mould and FYM+vermicompost (1:1) ratio. Basal portion of pear cuttings was dipped into 100 ppm IBA solution for 24 hours and then planted in nursery bed at a spacing of 15×10 cm2. The overall best performance was recorded in media soil+FYM (1:1) for most of the parameters. Numbers of roots cutting-1 (13.56), percentage (%) of rooted cuttings (69.70%), numbers of leaves (29.28), success percentage (92.59%) and survival percentage (78.18%). The media, soil+vermicompost (1:1) performed well for root length (21.90 cm) and shoot length (34.39 cm). Soil, when used alone as a growing medium showed the least response and provided unsatisfactory results for all the parameters. [ABSTRACT FROM AUTHOR]

The sample showing disease (sheath blight) symptoms in rice were collected from six states Gujarat, Karnataka, Pantnagar, Uttar Pradesh, Haryana and Punjab. The isolates (Gujarat, Karnataka, Pantnagar, Uttar Pradesh, Haryana and Punjab) of R. solani, were isolated on PDA plates were incubated for 5 days at 28±1 °C. Colony colour, growth pattern, and diameter growth showed great diversity in all the isolates. Based on the colony pigmentation, all the isolates were assigned into 4 groups: dark brown, dirty white, milky white and Yellowish brown. Isolates were grown on five different media; PDA was found the best media for growth and development in comparison to others. The maximum growth was found in two isolates, Gujarat and Karnataka (90 mm or 89.07) after 72 hrs. The maximum number of sclerotia was recorded in Gujarat isolate (125.33) followed by Karnataka (75.67) on Czapek's dox agar while the minimum number of sclerotia was observed in Pant Nagar (6.33) on yeast extract agar medium. The maximum weight of sclerotia was recorded in Gujarat isolate (194.02 mg) followed by Karnataka (186.79 mg) on PDA medium. The fourteen days old broth culture of oat meal broth of different isolate of R. solani significantly reduced the radical length and plumule length of the germinated seeds of Pusa Basmati-1 and Tetep as compared to check. Tetep showed the less reduction in germination per cent than Pusa Basmati-1, known as moderately resistant cultivar. The effect of Gujarat isolates was found the highly pathogenic than other isolates on seed germination of both the cultivar. [ABSTRACT FROM AUTHOR]