Flowering Phenology Research Articles

Long-term trends and influence of climate and land-use changes on pollen profiles of a Mediterranean oak forest

Climate change is disrupting phenology and interaction patterns of natural ecosystems, but also human activities that modify land-uses have a direct impact, especially on species distribution and loss of biodiversity. The objective of this study is to evaluate the impact of climate and land-use changes on phenology and airborne pollen spectrum in a Mediterranean natural area, dominated by Quercus Forest and ‘dehesa’, in the South of the Iberian Peninsula. 61 different pollen types were identified over a 23-year period (1998–2020), mainly from trees and shrubs, such as Quercus, Olea, Pinus or Pistacia, and from herbaceous plants, such as Poaceae, Plantago, Urticaceae or Rumex. A comparison of pollen data from the first years of the study (1998–2002) up recent years (2016–2020), showed a substantial decrease in the relative abundance of pollen from autochthonous species associated with natural areas, such as Quercus or Plantago. However, the relative abundance of the pollen from cultivated ones such as Olea and Pinus, which is used for reforestation has increased. Regarding flowering phenology trends, our analyses revealed variations between −1.5 and 1.5 days per year. Taxa showing an advance phenology were Olea, Poaceae and Urticaceae, whereas Quercus, Pinus, Plantago, Pistacia or Cyperaceae experienced delayed pollination.Meteorological trends in the area generally resulted in an increase in both minimum and maximum temperatures, along with a decrease in precipitations. Changes in pollen concentration and phenology were correlated with changes in air temperatures and precipitation, although the positive or negative influence varied for each pollen type. The results suggest that climate change together with those motivated by land cover changes lead by human activities are having an impact on the phenology and pollen concentration, with the related consequences on pollination and therefore biodiversity more concerning in threatened areas as the Mediterranean Basin.

Climate change impacts flowering phenology in Gongga Mountains, Southwest China

Flowering phenology of plants, which is important for reproductive growth, has been shown to be influenced by climate change. Understanding how flowering phenology responds to climate change and exploring the variation of this response across plant groups can help predict structural and functional changes in plant communities in response to ongoing climate change. Here, we used long-term collections of 33 flowering plant species from the Gongga Mountains (Mt. Gongga hereafter), a biodiversity hotspot, to investigate how plant flowering phenology changed over the past 70 years in response to climate change. We found that mean flowering times in Mt. Gongga were delayed in all vegetation types and elevations over the last 70 years. Furthermore, flowering time was delayed more in lowlands than at high elevations. Interestingly, we observed that spring-flowering plants show earlier flowering times whereas summer/autumn plants show delayed flowering times. Non-synchronous flowering phenology across species was mainly driven by changes in temperature and precipitation. We also found that the flowering phenology of 78.8% plant species was delayed in response to warming temperatures. Our findings also indicate that the magnitude and direction of variation in plant flowering times vary significantly among species along elevation gradients. Shifts in flowering time might cause trophic mismatches with co-occurring and related species, affecting both forest ecosystem structure and function.

Pollination ecology of an important medicinal plant Hellenia speciosa (J.Koenig) S.R.Dutta of Asiatic tropics

Abstract. Samanta A, Bera B, Karmakar P. 2023. Pollination ecology of an important medicinal plant Hellenia speciosa (J.Koenig) S.R.Dutta of Asiatic tropics. Biodiversitas 24: 3152-3161. Plants often show various floral traits that help them to achieve reproductive fitness. Floral adaptive traits help to maximize the possibility of outcrossing, even for clonally propagated plants. Furthermore, seed setting through successful pollination increases genetic diversity in clonal populations. This present study aimed to describe the flowering phenology, flower biology, pollinators, and breeding system of Hellenia speciosa, a perennial herb with rhizomes from the Costaceae family. According to our study, a pollen-ovule ratio of 210:1 indicates that the plant tends to facultative autogamy; however, the plant exhibits traits such as a large landing labellum for pollinators, bilabiate floral architecture, nototribic blossoms, a prominent nectar guide, abundant floral nectar (27.64±2.661 µL/flower), and high seed set through xenogamy (68.6± 3.07 standard error) to improve reproductive success through outcrossing. Here, the plant is pollinated by two hymenopteran members, namely Xylocopa auripennis and Amegilla zonata. Despite its ample nectar production, the plant is hardly visited by any honey bee species. GCMS analysis of floral nectar found 2-hexanol and derivatives of xylose were probably responsible for pollinator specificity and honey bee exclusion events, respectively.

Inter- and intra-annual variation in the pulsed flowering phenology of the columnar cactus Pilosocereus leucocephalus and its relation to temperature, rainfall and plant size

Floral phenology involves the initiation and development of ecological and physiological processes (e.g. pollination, germination, etc.) that contribute to the successful recruitment of a plant species. However, aspects related to the inter and intra-annual variation of flowering patterns have been poorly studied, including pulsed flowering, which is a rare phenology in angiosperm plants with only three cases known in the family Cactaceae. Here, we analyzed the pulsed flowering phenology of the columnar cactus Pilosocereus leucocephalus between and within years and its relation to rainfall, environmental temperature, and plant size. We recorded the number of receptive flowers displayed by an initial population of 82 individual plants for five consecutive years in central Veracruz, Mexico. We calculated and compared 14 descriptors of the phenological pattern and found variation in flower production both within and between years; however, across years, the phenological pattern was consistently extended, pulsed, slightly synchronous, and with a low reproductive potential. Flower production was positively correlated with the maximum temperature of the fifteenth day before anthesis and poorly correlated with rainfall at the study site. The accumulated flower number over five years was positively related to cactus size. Overall, our results support the idea that the pulsed floral phenology of this cactus is a result of resource limitation that forces individuals to rest and restore the resources needed for flower production.

Flowering Phenology of Olive Cultivars in Two Climate Zones with Contrasting Temperatures (Subtropical and Mediterranean)

The large amount of olive cultivars conserved in germplasm banks can be used to overcome some of the challenges faced by the olive growing industry, including climate warming. One effect of climate warming in olive is the difficulty to fulfill the chilling requirements for flowering due to mild winter temperatures. In the present work, we evaluate seven olive cultivars for their adaptation to high winter temperatures by comparing their flowering phenology in the standard Mediterranean climate of Cordoba, Southern Iberian Peninsula, with the subtropical climate of Tenerife, Canary Islands. Flowering phenology in Tenerife was significantly earlier and longer than in Cordoba. However, genotype seems to have little influence on the effects of the lack of winter chilling temperatures, as in Tenerife. This was found even though the cultivars studied had a high genetic distance between them. In fact, all the cultivars tested in Tenerife flowered during the three-year study but showed asynchronous flowering bud burst. ‘Arbequina’ showed an earlier day of full flowering compared with the rest of the cultivars. The results observed here could be of interest to refine the phenological simulation models, including the length of the flowering period. More genetic variability should be evaluated in warm winter conditions to look for adaptation to climate warming.

Fire reduces eucalypt forest flowering phenology at the landscape-scale

Plant phenology describes the timing of reproductive events including flowering and fruiting, which for many species are affected by fire disturbance. Understanding phenological responses to fire provides insights into how forest demographics and resources may shift alongside increasing fire frequency and intensity driven by climate change. However, isolating the direct effects of fire on a species' phenology and excluding potential confounders (e.g. climate, soil) has been difficult due to the logistical challenges of monitoring species-specific phenological events across myriad fire and environmental conditions. Here, we use CubeSat-derived crown-scale flowering data to estimate the effects of fire history (time since fire and fire severity over a 15-year time span) on flowering of the eucalypt Corymbia calophylla across a Mediterranean-climate forest (814km2) in southwest Australia. We found that fire reduced the proportion of flowering trees at the landscape-scale, and flowering recovered at a rate of 0.15 % (±0.11% SE) per year. Further, this negative effect was significant due to high crown scorch fires (>20% canopy scorch), yet there was no significant effect from understory burns. Estimates were obtained using a quasi-experimental design which identifies the effect of time since fire and severity on flowering by comparing proportional flowering within target fire perimeters (treatment) and adjacent past fire perimeters (control). Given the majority of fires studied were managed fuel reduction burns, we applied the estimates to hypothetical fire regimes to compare flowering outcomes under more or less frequent prescribed burning. This research demonstrates the landscape-scale effects of burning on a tree species' reproduction, which could broadly impact forest resiliency and biodiversity.

Flowering phenology of species with similar flower colours in species-rich communities

Within a community, co-occurring plant species are expected to diverge in floral display or flowering phenology to decrease interspecific competition and thus increase intraspecific pollination. However, co-occurring species can also benefit from floral signal standardisation (similar colour signals among flowers of different species) because it facilitates pollinator attraction. Considering the interaction of flower colour display and flowering phenology, we investigated the visual similarity of rewarding flowers among species from highly diverse tropical and temperate vegetation types. For six groups of co-occurring, closely related bee-pollinated species with similar floral displays from Brazilian campo rupestre (51 species) and Spanish Mediterranean vegetation (30 species), we first investigated whether flower colours can be discriminated by bees based on colour locus distance in the bee vision hexagon. We then tested whether flowering phenology overlapped or was segregated. We found that within both vegetation regions, flower colour was generally not distinguishable within groups by bees. The small perceptual distance of colour loci in the bee visual space did not enable discrimination. The flowering periods of the Mediterranean species overlapped, while the Brazilian campo rupestre species tended to have segregated phenologies. Mediterranean species may benefit from the increased standardisation of signals displayed during the short flowering season, while the sequential flowering phenology of campo rupestre species may decrease interspecific competition and help maintain a recognizable signal for bees over time, favouring flower constancy. We concluded that the standardisation of the floral colour signal within these two species-rich plant communities is advantageous for most of the species studied, despite having different flowering phenologies.

Intraspecific Variation in Functional Traits of Medicago sativa Determine the Effect of Plant Diversity and Nitrogen Addition on Flowering Phenology in a One-Year Common Garden Experiment.

Nitrogen deposition and biodiversity alter plant flowering phenology through abiotic factors and functional traits. However, few studies have considered their combined effects on flowering phenology. A common garden experiment with two nitrogen addition levels (0 and 6 g N m-2 year-1) and five species richness levels (1, 2, 4, 6, and 8) was established. We assessed the effects of nitrogen addition and plant species richness on three flowering phenological events of Medicago sativa L. via changes in functional traits, soil nutrients, and soil moisture and temperature. The first flowering day was delayed, the last flowering day advanced, and the flowering duration shortened after nitrogen addition. Meanwhile, the last flowering day advanced, and flowering duration shortened along plant species richness gradients, with an average of 0.64 and 0.95 days change per plant species increase, respectively. Importantly, it was observed that plant species richness affected flowering phenology mainly through changes in plant nutrient acquisition traits (i.e., leaf nitrogen and carbon/nitrogen ratio). Our findings illustrate the non-negligible effects of intraspecific variation in functional traits on flowering phenology and highlight the importance of including functional traits in phenological models to improve predictions of plant phenology in response to nitrogen deposition and biodiversity loss.

The influence of climate warming on flowering phenology in relation to historical annual and seasonal temperatures and plant functional traits.

Climate warming has the potential to influence plant flowering phenology which in turn can have broader ecological consequences. Herbarium collections offer a source of historical plant data that makes possible the ability to document and better understand how warming climate can influence long-term shifts in flowering phenology. We examined the influence of annual, winter, and spring temperatures on the flowering phenology of herbarium specimens for 36 species collected from 1884-2015. We then compared the response to warming between native and non-native, woody and herbaceous, dry and fleshy fruit, and spring vs summer blooming species. Across all species, plants flowered 2.26 days earlier per 1°C increase in annual average temperatures and 2.93 days earlier per 1°C increase in spring onset average temperatures. Winter temperatures did not significantly influence flowering phenology. The relationship of temperature and flowering phenology was not significantly different between native and non-native species. Woody species flowered earlier than herbaceous species only in response to increasing annual temperatures. There was no difference in the phenological response between species with dry fruits and those fleshy fruits for any of the temperature periods. Spring blooming species exhibited a significantly greater phenological response to warming yearly average temperatures than summer blooming species. Although herbarium specimens can reveal climate change impacts on phenology, it is also evident that the phenological responses to warming vary greatly among species due to differences in functional traits such as those considered here, as well as other factors.

Temperature Induced Flowering Phenology of Olea ferruginea Royle: A Climate Change Effect

Studies from different parts of the world have generated pieces of evidence of climate change’s effects on plant phenology as indicators of global climate change. However, datasets or pieces of evidence are lacking for the majority of regions and species, including for the climate-sensitive Himalayan biodiversity hotspot. Realizing this gap in information, and the wide-ranging implications of such datasets, we integrated real-time field observations and long-term herbarium records to investigate the changes in the spring flowering phenology of Olea ferruginea Royle, commonly known as the Indian Olive, in response to the changing climate in the western Himalayas. We attempted to create phenological change model using the herbarium records and field observations after recording the current dates of flowering and overall temperature trends from the study area over the last four decades from the five regional meteorological observatories of the Jammu province managed by Indian Meteorological Department (IMD) in Jammu and Kashmir. When considering current flowering dates along with herbarium information (years 1878–2008) for O. ferruginea, our Generalized Additive Model (GAM) showed 15–21 days-early flowering over the last 100 years significantly (p < 0.01). Results of the Mann–Kendall test showed increasing trends of TMin for all seasons significantly (p < 0.05) for Jammu province whereas TMax was only for the spring season. The increasing TMin of spring, summer, and autumn seasons also influenced the flowering phenology of O. ferruginea significantly (p < 0.01). By demonstrating the integrated use of methodological tools for finding long-term phenological changes in response to climate change, this work bridges knowledge gaps in phenological research from the developing world in general and the Himalayas in particular.

Study on the Phenology of Three Fruit Trees Species in Purwodadi Botanical Gardens, East Java, and Its Relationship with Mesoclimates

Nowadays the study of phenology has taken an important contribution to climate change research. Therefore this study observed local fruit trees species collected in the Purwodadi Botanical Gardens (PBG); they were Flacourtia rukam (Zoll & Moritzi), Limonia acidissima L., and Manilkara kauki (L) Dubard. We used fruit phenology data from 2014 to 2018 as secondary data to describe the changes. We also observed the weekly phenology of flowering and fruiting for three years from 2019 to 2022. At the same time, mesoclimates components included precipitation, maximum and minimum temperature were daily recorded by the PBG weather station measurement. Data pairs were then analyzed by using a structural modeling of WarpPLS to determine the relationship among mesoclimates and phenology variables. Research showed that phenology of flowering and fruiting of F. rukam, L. acidisissima, and M. kauki was significantly shifted from 2014 to 2022, along with changes in rainfall patterns, maximum and minimum temperatures in the PBG. Based on the Friedman test, it was shown that the maximum and minimum temperatures significantly changed (p<0.05). Five months of mesoclimates were significant predictors and affected before the measurement of phenological flowering and fruiting of three species. High precipitation significantly reduced maximum temperature, and increased minimum temperature. The high precipitation reduced the probability of flowering and fruiting initiation, except for those of L. acidissima. Increasing maximum temperature reduced flower and fruit set of F. rukam and L. acidisissima, while it reduced flowering of L. acidissima. Furthermore, minimum temperature induced flowering, except in L. acidissima.

Sipping on Nectar: Butterflies and Flowers in Oak Savannas on Vancouver Island, British Columbia

Photo 1. View of a Garry oak savanna field site in Camrose Park, Victoria, BC, Canada. Oak savannas in the region are characterized by rocky outcroppings, a dense understory of forbs, and an open canopy of mostly Garry oak trees (Quercus garryana) mixed in with Douglas Firs (Pseudotsuga menziesii) and Arbutus (Arbutus menziesii). In front of the treeline, the nectar-less yellow flowers of invasive Scotch Broom (Cytisus scoparius) can be seen. Photo credit: Stephanie A. Rivest. Photo 2. Examples of flowering plants recorded in Garry oak savannas around Victoria, BC. Western Buttercup (top left panel: Ranunculus occidentalis) and Sea Blush (top right panel: Plectritis congesta) are native to the region, while Himalayan Blackberry (bottom right panel: Rubus armeniacus) and Cornflower (bottom right panel: Centaurea cyanus) are non-native. Photo credit: Stephanie A. Rivest. Photo 3. A native Propertius Duskywing (Erynnis propertius) butterfly foraging for nectar on a native White Brodiaea (Triteleia hyacinthine) flower in an oak savanna in Victoria, BC. Photo credit: Stephanie A. Rivest. Photo 4. A native Painted Lady (Vanessa cardui) butterfly foraging for nectar on a native Oceanspray (Holodiscus discolor) flower in an oak savanna in Victoria, BC. Photo credit: Stephanie A. Rivest. Photo 5. A native Lorquin's Admiral (Limenitis lorquini) perched on a researcher's hand during a field survey of an oak savanna in Victoria, BC. The butterfly's proboscis explores the researcher's skin, hoping to collect the sodium from sweat. Photo credit: Stephanie A. Rivest. Source paper: These photographs illustrate the article “Flowering phenology influences butterfly nectar foraging on non-native plants in an oak savanna” by Stephanie A. Rivest, E.M. Wolkovich, and Heather M. Kharouba published in Ecology. https://doi.org/10.1002/ecy.4004

Banker Plant Bonuses? The Benefits and Risks of Including Brassicas in Field Margins to Promote Conservation Biocontrol of Specialist Pests in Oilseed Rape.

European agri-environment schemes include the use of flower-rich field margins to promote on-farm biodiversity, but species mixtures rarely include Brassicaceae. As pests of oilseed rape (OSR; Brassica napus) and their parasitoids are mostly brassica specialists, including brassica 'banker plants' in the mixtures would help support these important biocontrol agents and improve pest control throughout the crop rotation. We assessed the potential of six brassicaceous plants (replicated plots grown in the field) to enhance populations of parasitoids of OSR pests whilst minimising proliferation of their pest hosts. Fodder radish (Raphanus sativus) facilitated high production of parasitoids of the pollen beetle pest (Brassicogethes aeneus) but may proliferate Ceutorhynchus weevil pests due to low parasitism. Turnip rape (B. rapa) and the B. rapa hybrid 'Tyfon' showed potential to perform a trap cropping function for pests, but their early flowering phenology resulted in B. aeneus larvae escaping parasitisation, potentially assisting proliferation of this pest. Forage rape B. napus exhibited similarly high B. aeneus parasitoid production characteristics to R. sativus but did not potentiate problems with other pests, indicating that it would be a favourable banker plant option. Careful selection of plants in field margin mixtures is therefore needed to maximise their benefits and ideally the whole crop pest-beneficial complex needs to be studied, as focus on a single major pest risks unintended consequences with other pest problems.

Seasonality in the equatorial tropics: Flower, fruit, and leaf phenology of montane trees in the highlands of Southwest Uganda

AbstractPhenology influences many forest functions and can inform forest conservation and management, yet representative phenological data for most common tropical forest tree species remain sparse or absent. Between June 2011 and December 2013, we investigated flowering, fruiting, and leafing patterns in the Bwindi Impenetrable National Park, a montane forest located near the equator in Uganda, drawing on 16,410 observations of 530 trees of 54 species located between 2066 and 2527 m in elevation. The park's climate is equatorial with two wet and dry seasons each year. Flowering and fruiting were strongly seasonal while patterns in leafing were less pronounced. Flower occurrence peaked at the beginning of the short dry season followed by a pronounced trough during the beginning and the middle of the short wet season. Fruit occurrence had a pronounced peak during high rainfall months in March through April with most fruits ripening during drier months in May through July. Fruit scarcity was observed for a 4‐month period spanning September to December and most flushing of leaves noted at the end of the wet season in November and December. Our binomial generalized linear mixed models indicated that flowering and fruiting were negatively associated with temperature and that leafing activity was positively associated with rainfall and temperature. These findings are consistent with the insolation‐ and water‐limitation hypotheses suggesting that the seasonally varying availability of resources such as light, water, and nutrients determines these phenological patterns. Ideally, prolonged, multi‐year community‐level studies would be supported so as to better characterize the influence of climate and of climate variability.

Preadapted to adapt: underpinnings of adaptive plasticity revealed by the downy brome genome

Bromus tectorum L. is arguably the most successful invasive weed in the world. It has fundamentally altered arid ecosystems of the western United States, where it now found on an excess of 20 million hectares. Invasion success is related to avoidance of abiotic stress and human management. Early flowering is a heritable trait utilized by B. tectorum, enabling the species to temporally monopolize limited resources and outcompete the native plant community. Thus, understanding the genetic underpinning of flowering time is critical for the design of integrated management strategies. To study flowering time traits in B. tectorum, we assembled a chromosome scale reference genome for B. tectorum. To assess the utility of the assembled genome, 121 diverse B. tectorum accessions are phenotyped and subjected to a genome wide association study (GWAS). Candidate genes, representing homologs of genes that have been previously associated with plant height or flowering phenology traits in related species are located near QTLs we identified. This study uses a high-resolution GWAS to identify reproductive phenology genes in a weedy species and represents a considerable step forward in understanding the mechanisms underlying genetic plasticity in one of the most successful invasive weed species.

Phenology and Diversity of Weeds in the Agriculture and Horticulture Cropping Systems of Indian Western Himalayas: Understanding Implications for Agro-Ecosystems.

Weeds are a major threat to agriculture and horticulture cropping systems that reduce yield. Weeds have a better ability to compete for resources compared to the main crops of various agro-ecosystems and act as a major impediment in reducing overall yield. They often act as energy drains in the managed agroecosystems. We studied weed infestation for five different agro-ecosystems in the part of Indian Western Himalayas represented by paddy, maize, mustard, apple and vegetable orchards. Systematic random sampling was done to record flowering phenology and diversity of weeds during the assessment period 2015-2020. We recorded 59 weed species, taxonomically distributed among 50 genera in 24 families. The Asteraceae family has the most species (15% species), followed by Poaceae (14% species), and Brassicaceae (12% species). The Therophytes were the dominant life form followed by Hemicryptophytes. The majority of the weeds were shown to be at their most blooming in the summer (predominantly from June to July). The Shannon index based diversity of weeds ranged from 2.307-3.325 for the different agro-ecosystems. The highest number of weeds was in the horticulture systems (apple > vegetable) followed by agriculture fields (maize > paddy > mustard). Agriculture and horticulture cropping systems were distinguished using indicator species analysis, which was supported by high and significant indicator values for a number of species. Persicaria hydropiper, Cynodon dactylon, Poa annua, Stellaria media, and Rorippa palustris had the highest indicator value in agriculture cropping systems, while Trifolium repens, Phleum pratense, and Trifolium pratense had the highest indicator value in horticulture cropping systems. We found that eleven weed species were unique to apple gardens followed by nine in maize, four in vegetables, two in mustard and one in paddy fields. Spatial turnover (βsim) and nestedness-resultant components (βsne) of species dissimilarity revealed dissimilarity lower than 50% among the five cropping systems. The study is expected to assist in formulating an appropriate management strategy for the control of weed infestation in the study region.

Flowering phenology of African pear (Dacryodes edulis (G. Don)HJ Lam) under Nigerian ecological conditions

A-three-year trial of flowering phenological characteristics of 150 African pear tree were studied in South-South and South-East Nigeria to study the flowering phenology of African pear (Dacryodes edulis) under Nigerian Ecological conditions. Five States were selected, three locations in each State, ten mature African pear trees were selected and tagged for data collection. Also, meteorological data were collected for three years. The surveyed trees were monitored till flowering time. Data were collected on start of flower formation, peak of flowering, days to anthesis, average temperature and rainfall during the months of flowering. Data collected were analysed using analysis of variance and percentages were calculated where appropriate. Result obtained indicated that there were variations in the time of flowering. African pear had peak flowering in January in Imo, Rivers and Delta States for 2013-2015, while Abia and Enugu had their peak flowering for the same period in February and March, respectively. African pear flowered between the temperatures of 27.0oC to 29.5oC. Rainfall ranged from 0.00mm to 137.50mm. The flowering season was affected mainly by temperature. Time of inflorescence flower bud formation to anthesis lasted for 2-5 days, but majority took 3-4 days to reach anthesis. In the study, under Nigerian ecological condition, African pear flowered when the temperature was high and when humidity was low. The planting of African pear that flowers around January and February should be encouraged because they had the highest yield and potential to ripe during hunger period.

Environment-specific selection alters flowering-time plasticity and results in pervasive pleiotropic responses in maize.

Crop genetic diversity for climate adaptations is globally partitioned. We performed experimental evolution in maize to understand the response to selection and how plant germplasm can be moved across geographical zones. Initialized with a common population of tropical origin, artificial selection on flowering time was performed for two generations at eight field sites spanning 25° latitude, a 2800 km transect. We then jointly tested all selection lineages across the original sites of selection, for the target trait and 23 other traits. Modeling intergenerational shifts in a physiological reaction norm revealed separate components for flowering-time plasticity. Generalized and local modes of selection altered the plasticity of each lineage, leading to a latitudinal pattern in the responses to selection that were strongly driven by photoperiod. This transformation led to widespread changes in developmental, architectural, and yield traits, expressed collectively in an environment-dependent manner. Furthermore, selection for flowering time alone alleviated a maladaptive syndrome and improved yields for tropical maize in the temperate zone. Our findings show how phenotypic selection can rapidly shift the flowering phenology and plasticity of maize. They also demonstrate that selecting crops to local conditions can accelerate adaptation to climate change.

Sympatric co-existence of two ecotypes of Impatiens noli-tangere (Balsaminaceae) with different morphology and flowering phenology.

In angiosperms, intraspecific variation of flowering phenology may affect reproductive isolation and, consequently, speciation. This study focused on Impatiens noli-tangere (Balsaminaceae), which is distributed over broad latitudinal and altitudinal ranges in Japan. We aimed to reveal the phenotypic mixture of two ecotypes of I. noli-tangere with different flowering phenology and morphological traits in a narrow contact zone. Previous studies have shown that I. noli-tangere has early- and late-flowering types. The early-flowering type makes buds in June and is distributed at high-elevation sites. The late-flowering type makes buds in July and is distributed at low-elevation sites. In this study, we analyzed the flowering phenology of individuals at an intermediate elevation site where the early- and late-flowering types grow in sympatry (contact zone). We found no individuals showing intermediate flowering phenology at the contact zone, and early- and late-flowering types were clearly distinguishable. We also found that the differences in many other phenotypic traits between the early- and late-flowering types were maintained, including the number of flowers produced (total number of chasmogamous and cleistogamous flowers), leaf morphology (aspect ratio, number of serrations), seed traits (aspect ratio), and flower bud formation positions on the plant. This study showed that these two flowering ecotypes maintain many different traits in sympatry.

Differences in flowering phenology and seed production of four morning glory (Ipomoea) species in Japan

AbstractThe spread of morning glory (Ipomoea spp.) in soybean fields in Japan has severely decreased soybean yield. Yet, current control measures do not control the proliferation of Ipomoea spp. As little is known about the flowering period and seed production among the different invading Ipomoea spp., it is challenging to create targeted control measures based on ecological characteristics. This study aimed to reveal the characteristics of the flowering phenology and seed production of four morning glory species, namely, Ipomoea coccinea L. (red morning glory), Ipomoea lacunosa L. (pitted morning glory), Ipomoea hederacea L. Jacq. var. integriuscula A. Gray (entireleaf morning glory), and Ipomoea triloba L. (three‐lobe morning glory). Between 2017 and 2019, the four selected study species were grown under similar conditions of soil quality, irrigation, and environmental influences and their flowering phenology and seed data were recorded. The flowering period ranged from 36 to 40 days, and the initial flowering of I. triloba was approximately 2 weeks later than the others. I. coccinea had the highest flowering number and seed production, followed by I. lacunosa, I. triloba, and I. hederacea var. integriuscula. The fruit setting rate of I. triloba decreased later in the reproductive stage but tended to increase as the daily mean temperature increased on each flowering day. Thus, we report that the flowering phenology and seed production differed greatly among the Ipomoea spp. These findings can provide crucial insights into designing targeted species‐specific control measures against the spread of Ipomoea spp. in Japan.