Pollen Counts Research Articles

GAMYB transcription factor LoMYB65 from lily plays a vital role in pollen development

Lily (Lilium spp.) is an important horticultural crop, but its use is limited due to serious pollen contamination problems. There are many studies on pollen development in model plants, but few on flower crops such as lilies. Gibberellin (GA) is a large class of hormones and plays an important role in plant vegetative growth and reproductive development. GAMYB is a group of the R2R3-MYB family upregulated by gibberellin, and plays an important role in anther development. Here, we isolated a novel GAMYB, named LoMYB65, from lily, which was closely related to the AtMYB65 and AtMYB33 in Arabidopsis. Fluorescence quantitative PCR results showed that LoMYB65 was mainly expressed in lily anthers. LoMYB65 could be activated by 288 μmol · L−1 GA3 treatment and the LoMYB65 protein was located in the nucleus and cytoplasm, and had transactivation in yeast and tobacco leaf cells. The conserved motif within 226 amino acids of the C-terminal of LoMYB65 contributed to its transactivation. Overexpression of LoMYB65 caused dwarf phenotype, unnormal tapetum development, less seeds of siliques in transgenic Arabidopsis plants, the transgenic plants showed partly male sterile. Simultaneously, silencing of LoMYB65 with VIGS (Virus Induced Gene Silencing) in lily anthers caused unnormal pollen development and reduced the pollen amount. Overexpression of LoMYB65 in Arabidopsis and silencing of LoMYB65 in lily resulted in decreased pollen counts, so we speculate that LoMYB65 may be dose-dependent. Overall, these findings suggest that LoMYB65 may play an important role in anther development and pollen formation in lily. LoMYB65 may provide a useful candidate gene for pollenless breeding of lily.

Representation of the Hyrcanian forest (northern Iran) in modern pollen rain revealed by palynological and DNA-metabarcoding data

We studied the modern pollen rain in two different landscapes from Hyrcanian lowland forests up to the slopes of the Alborz Mountains in Gilan province for the first time. Pollen traps were installed for one year and moss samples were collected along two altitudinal transects from 100 to 1800 m and from 100 to 2300 m elevations. The results of pollen counting and environmental DNA barcoding (metabarcoding) of the collected pollen and moss samples were compared from 32 locations. In total, 81 vascular plant species from 36 families were identified by metabarcoding, and 68 taxa belonging to 39 families were identified by pollen counting. The pollen counting results reflect mainly wind-pollinated families, such as Betulaceae and Fagaceae while results from metabarcoding of the rbcL and ITS2 loci were more in line with the vegetation around the pollen traps and the moss samples. Furthermore, this study showed that the rbcL region is able to identify more taxa than the ITS2 region, while applying both markers provides higher confidence. Also using both metabarcoding and pollen data provides a better local and regional vegetation representation.

Relationship Between Annual Airborne Pollen Levels and Occurrence of Parkinson Disease, Amyotrophic Lateral Sclerosis, Myasthenia Gravis, Multiple Sclerosis, Spinocerebellar Degeneration, Huntington’s Disease, Shy-Drager Syndrome, Moyamoya Disease and Creutzfeldt- Jakob Disease Based on the National Registry Database of Specific Intractable Disease in Japan, 1974-2014: A Retrospective Study

Background: In Japan, pollen counts increased between 1977 and 1987, including three peaks (1978- 1980, 1982, 1984-1986) coinciding with triphasic Kawasaki disease (KD) outbreaks. Epidemiological findings have been then extensively accumulated that KD and related specific intractable diseases such as systemic vasculitis, collagen diseases, inflammatory bowel diseases, idiopathic dilated cardiomyopathy and further various cancers may be correlated to pollen exposure (PE). Methods and results: To elucidate the effects of PE on outbreaks of neurological intractable diseases (NIDs), we evaluated the annual occurrence of disorders in relation to pollen counts using data from a national database. Specifically, we evaluated the occurrence of Parkinson disease (PD), amyotrophic lateral sclerosis (ALS), Myasthenia Gravis (MG), multiple sclerosis (MS), spinocerebellar degeneration (SCD), Huntington’s disease (HUNTG), Shy-Drager syndrome, moyamoya disease and CreutzfeldtJakob disease (CJD). During 1975–2014, the 1984-86 peak of pollen scatter was the earliest big peak with which simultaneous increase in occurrence of PD, ALS, MG, MS, SCD and HUNTG coincided. Furthermore, simultaneous outbreaks of each NID coincided with subsequent ten peaks of pollen scatter till 2014. Our results showed statistically significant correlations for PD, ALS, MG, MS and SCD between the annual number of newly registered patients (nRPs) in the patient-registry year and annual pollen levels in the same patient-registry year. Significant correlations were also shown between the number of nRPs in the patient-registry year and annual pollen levels measured 3 years (PD), 6 years (PD, MG, MS, MMD), 9 years (PD, MS, MMD, CJD), 14 years (PD, CJD), and 16 years MG, MS, HUNTG and MMD before the patient-registry year. Conclusion: We assume that cumulative effects of PE during a decade or more before the diagnosis of NIDs might possibly trigger onset of NIDs when cumulative effects of PE as environmental stress overwhelmed immunoreactive threshold.

Exercise-induced bronchoconstriction is associated with air humidity and particulate matter concentration in preschool children.

Long-term exposure to air pollution is connected to asthma morbidity in children. Exercise-induced bronchoconstriction (EIB) is common in asthma, and the free running test outdoors is an important method for diagnosing asthma in children. It is not known whether momentary air pollution exposure affects the results of outdoor exercise tests in children. We analyzed all reliable exercise challenge tests with impulse oscillometry in children (n = 868) performed between January 2012 and April 2015 at Tampere University Hospital. Pollutant concentrations (PM2.5 , NO2 , and O3 ) at the time of the exercise test were collected from public registers. We compared the pollutant concentrations with the proportion and severity of EIB and adjusted the analyses for air humidity and pollen counts. Pollution levels were rarely high (median PM2.5 6.0 µg/m3 , NO2 12.0 µg/m3 , and O3 47.0 µg/m3 ). The relative change in resistance at 5 Hz after exercise did not correlate with O3 , NO2 or PM2.5 concentrations (p values 0.065-0.884). In multivariate logistic regression, we compared the effects of PM2.5 over 10 µg/m³, absolute humidity (AH) over 10 g/m³ and alder or birch pollen concentration over 10 grains/m³. High (over 10 g/m3 ) AH was associated with decreased incidence (OR 0.31, p value 0.004), and PM2.5 over 10 µg/m³ was associated with increased incidence (OR 1.69, p value 0.036) of EIB. Even low PM2.5 levels may have an effect on EIB in children. Of the other properties of air, only AH was associated with the incidence of EIB.

Genome-Wide Identification of MIKCc-Type MADS-Box Family Gene and Floral Organ Transcriptome Characterization in Ma Bamboo (Dendrocalamus latiflorus Munro).

Most bamboos die after flowering, and the molecular mechanisms responsible for flowering is poorly understood. The MIKCc-type MADS-box family gene is involved in the flowering process. To explore the mechanism of the MIKCc-type MADS-box gene and phytohormone regulation in the flowering of Dendrocalamus latiflorus Munro (D. latiflorus), characterized by extremely rapid growth and widely cultivated woody bamboo, we initially did a genome-wide analysis of the MIKCc-type MADS-box gene in D. latiflorus. In the meantime, transcriptome analysis was performed using the floral organs. A total of 170 MIKCc-Type MADS-Box genes were identified and divided into 15 categories. The cis-acting element analysis in promoters regions revealed that MIKC-type MADS-box family genes were associated with hormones, including auxin, abscisic acid (ABA), gibberellin (GA) and jasmonic acid (JA), which was found at 79, 476, 96, 486 sites and cover 61, 103, 73, 128 genes. Genome synteny analysis showed subgenome AA and BB were better than CC and obtained 49, 40, 39 synteny genes compared with Oryza sativa (O. sativa). In transcriptome analysis of floral organs, the enriched pathway from DEGs included circadian, vernalization and gibberellin pathways associated with the flowering process. We found that the jasmonic acid synthesis gene is highly expressed in the pistil, which may be the cause of Ma bamboo pollen abortion. The expression profile showed that most MIKC-type MADS-box genes exhibited high expression in flower organs. The consequences of this study will provide insight into the irregular flowering and low pollen counts of Ma bamboo.

Effects of fiber electrostatic cling and moisture regain on timothy grass pollen attraction

The purposes of this study are to determine if there is a relationship between fabric parameters such as electrostatic charge and moisture regain on the attraction of Timothy grass pollen, and to determine the effects of various fabric treatments on their pollen attraction. Half of the fabrics were treated with acidic acid (vinegar), basic (ammonia), and fabric softener. Both untreated and treated fabrics were exposed to Timothy grass pollen. The pollen counts of both untreated and treated fabrics were then determined. The results showed that untreated wool was found to be the least attraction to Timothy grass pollen while nylon was the most attracted to this pollen. The relationship between electrostatic cling time and pollen attraction was not established in the fibers studied except nylon, which had the highest cling time and the highest pollen count. When examining the relationship between fiber moisture regain and their pollen attraction, the results showed that other than wool, which had the highest MR and the lowest pollen count, no consistency was found between the MR and pollen count for the rest of the fibers tested. For fabric treatments, the results showed that dilute acidic acid was found to be most effective in reducing the pollen counts in all fiber fabrics except made no change in wool. Fabric softener was found to be the least effective treatment in lowering the fabric pollen attraction on all fiber fabrics except nylon.

Exploring the effects of seasons, diurnal cycle, and heights on airborne pollen load in a Southeast Asian atmospheric condition.

Aeropollen can induce detrimental effects, particularly in respiratory airways. Monitoring local aeropollen is essential for the management of pollen allergic patients in each area. However, without resources for constant monitoring, pollen counts are subjected to biases imposed by the choices of sampling season, time of collection, and location. Therefore, the effects of these factors must be better understood. This study investigated the dynamics of aeropollen types through seasonal variation, diurnal cycle and different heights from the ground in Bangkok, Thailand. Aeropollen samples were collected for 12 months at the Faculty of Science, Mahidol University in Bangkok, using a RotoRod Sampler®. For the investigation of diurnal effect, pollen was collected at 7 a.m., 10 a.m., 1 p.m., 4 p.m., and 7 p.m. For the study of height effect, data were collected at 2, 10, and 18 meters above ground. This is the first study of the effects of diurnal cycle and height variation on airborne pollen count in Southeast Asia. The results showed the highest concentration of aeropollen was observed in November, which was at the beginning of the northeast monsoon season in Bangkok, whereas the lowest concentration was recorded in July (rainy season). Interestingly, the lowest airborne pollen concentration recorded in July was greater than the high level of most standards. Grass pollen was found as the major aeropollen. The highest total pollen concentration was detected at 1 p.m. The maximum pollen quantity was detected at 10 meters from the ground. However, the total aeropollen concentration was extremely high (>130 grains/m3) at all elevated heights compared to other studies that mostly found at lower height (approximately 1-2 m above ground). The result suggested that pollen concentrations of most pollen types increased as height increased. This study also illustrated the correlation between aeropollen quantity and local meteorological factors. This aeropollen survey reported that pollen concentration and diversity were affected by seasonal variation, diurnal cycle, and height from the ground. Understanding these relationships can help with predictions of aeropollen type and quantity.

Aeroallergen Monitoring by the National Allergy Bureau: A Review of the Past and a Look Into the Future

Monitoring aeroallergens has a long history within the American Academy of Allergy, Asthma & Immunology. The Aeroallergen Network of the National Allergy Bureau is composed mainly of members of the American Academy of Allergy, Asthma & Immunology, whose objectives are to enhance the knowledge of aerobiology and its relationship to allergy, increase the number of certified stations, maintain the standardization and quality of aerobiology data, improve the alert and forecast reporting system, and increase ties with other scientific entities inside and outside the United States. The public has a keen interest in pollen counts and pollen forecasts, as do many health professionals in the allergy community. In this review, we explore the past, present, and future of allergen monitoring with a focus on methods used for sampling, the training of those performing the analysis, and emerging technologies in the field. Although the development of automated samplers with machine intelligence offers great promise for meeting the goal of a fully automated system, there is still progress to be made regarding reliability and affordability.

Cofactors, age at onset, allergic comorbidities and gender are different in patients sensitized to omega-5 gliadin and Pru p 3

Aim of this study is to clarify the impact of cofactors on allergic reactions in patients sensitized to LTP and ω-5-gliadin. We retrospectively examined the charts of our outpatients from January 2015 to July 2019 and identified 157 patients seen for urticaria/angioedema or anaphylaxis after a meal, in presence or absence of cofactors and sensitized to LTPs (Pru p 3 and/or Tri a 14) and/or ω-5-gliadin (Tri a 19). we compared LTPs-positive patients and those sensitized to Tri a 19 in order to assess the difference in cofactors involved and in frequency of clinical presentation. Our data show that exercise is the most frequent cofactor in FDEIAn and the involvement of exercise, alcohol and multiple cofactors was more frequently found in males than in females. We found that exercise, pollen counts peaks and multiple cofactors were more often related to anaphylaxis than mild reactions. Finally, we performed a comparison between patients LTPs+ and Tri a 19+ that showed in the latter group a lower frequency of allergic comorbidities, a higher median age at the onset of symptoms and frequency of alcohol exposure. Our data show that the search for possible cofactors involved in food allergy is essential not only for diagnostic purposes, but also for risk assessment strategies.

Aeropalynology of Parthenium hysterophorus L. in Relation to Meteorological Parameters from Srinagar Valley of Garhwal Himalaya, Uttarakhand

Parthenium hysterophorus (congress grass) is a harmful weed and its pollen grains are important allergens. Due to its minute size and allergenic activity, this particular type of pollen is selected for the study. The aeropalynological survey was conducted for the year 2019 at Chauras Campus, Hemvati Nandan Bahuguna Garhwal University, Srinagar, Uttarakhand. It is located on the right bank of the Alaknanda river (30°13’35.81”N & 78°48’11.05”E; 560 m amsl). A Rotarod sampler was used for air sampling. The maximum pollen count was observed in July. To evaluate the correlation matrix in R software, correlations (Pearson’s and Spearsman’s) between pollen count and meteorological parameters have been calculated. Back trajectory analysis has also been done using NOAA HYSPLIT MODEL.

Prenatal diagnosis and management of fetal arhinia during pregnancy in order to optimize neonatal outcome

Objectives: To discuss the prenatal diagnosis and management of fetal arhinia in order to optimize neonatal outcome Methods: This is a case report and discussion of the clinical management of fetal arhinia and review of appropriate literature Results: A fetus with arhinia diagnosed prenatally by ultrasound was managed optimally for neonatal outcome Conclusion: Prenatal diagnosis of arhinia is a rare congenital malformation that requires consultation and delivery at a specialized children’s hospital with the capability of immediate respiratory support at delivery..

Relationship Between Annual Airborne Pollen Levels And Occurrence Of Thyroid, Skin, Esophagus, Kidney And Ovary Cancers, And Leukemia, Multiple Myeloma And All Cancers: A Retrospective Study Based On The National Registry Database Of Cancer Incidence In Japan, 1975–2015

Background: In Japan, pollen counts increased between 1977 and 1987, including three peaks (1978- 1980, 1982, 1984-1986) coinciding with Kawasaki disease (KD) outbreaks. Epidemiological findings have been gradually accumulated that KD and related specific intractable diseases and further cancers may be correlated to pollen exposure (PE). Methods and results: To elucidate the effects of PE on occurrence of thyroid, skin, esophagus, kidney and ovary cancers, and leukemia, multiple myeloma and all cancers, we evaluated the annual onsets of malignant tumors in relation to pollen counts using data from a national database. Increased rates of these cancers were observed during pollen counts increasing period between 1977 and 1987. Significant correlations were observed between the annual number of newly registered patients (nRPs) and the annual pollen levels (PL) measured with a lag of 2 years for skin and kidney cancers, 4 years for thyroid cancer, 6 years for skin, esophagus cancers, leukemia and multiple myeloma, 8 years for thyroid cancer, and 2,3 and 6 years for all cancers. Peaks of number of thyroid cancer in 2013, 1990 and 1980 are discussed about as compared with other cancers regarding effect of radioactive pollutants occurred from three nuclear plant accidents. Conclusion: Data suggest newly that the cumulative effects of PE within 2,3,4,6,8 years prior to diagnosis might possibly trigger incidence of eight cancers and malignant tumors.

HOURLY VARIATION OF POLLEN COUNTS

<h3>Introduction</h3> Patients with pollen allergies need to be aware about the time of day when they are exposed to the higher pollen levels. <h3>Methods</h3> we first evaluated the accuracy of the pollen measurements of an automated real-time pollen imaging sensor (APS–300) to that of the Rotorod sampler with manual counting at the Atlanta Allergy and Asthma Clinic (AAAC) located ∼30 km northwest of downtown Atlanta (i.e. the Marietta site). We then investigated the diurnal variability of pollen levels at all three of our study sites (Marietta, Emory ∼ 7 km northeast of downtown Atlanta, and SouthFace at downtown Atlanta) from 24 March to 31 March 2021, which measured the highest pollen levels during our study period. We also averaged the hourly pollen concentrations during this week to reduce day-to-day fluctuations due to weather conditions. <h3>Results</h3> Analysis of data collection knows that real-time pollen monitoring measured lower pollen levels between 4 am to noon and then a gradual increase with the peak pollen counts at approximately 2 PM to 9 pm. <h3>Conclusions</h3> Hourly pollen counts are difficult to measure but the automated real-time imaging sensor enables accurate hourly counts. Clinical implication is that patients with pollen allergy should plan their outdoor activities in the morning when the pollen counts are lowest.

Relationship among airborne pollen, sensitization, and pollen food allergy syndrome in Asian allergic children.

Causes of pediatric pollen food allergy syndrome (PFAS) differ depending on airborne pollen levels in a particular region. We aimed to analyze airborne pollen counts, IgE sensitization rates, and PFAS incidence among children with allergies in South Korea and Japan. This cross-sectional study included children aged 5-17 years with allergies in 2017. Airborne pollen samples were collected from Busan in South Korea, and Fukuoka and Tochigi in Japan. Questionnaires were used to assess bronchial asthma, seasonal allergic rhinitis, atopic dermatitis, food allergy, and PFAS. The serum IgE specific to Dermatophagoides pteronyssinus, pollen, tomato, and peach were investigated. In total, 57, 56, and 20 patients from Busan, Fukuoka, and Tochigi, respectively, were enrolled. Airborne Japanese cedar and cypress pollen were predominant in Fukuoka and Tochigi, whereas pine and alder pollen were predominant in Busan. Children with allergies in Fukuoka and Tochigi had a significantly higher sensitization rate to Japanese cedar, cypress, juniper, orchard grass, ragweed, Japanese hop, and tomato compared with children in Busan. In Fukuoka and Tochigi, where Japanese cedar and cypress pollen were frequently scattered, high sensitizations among allergic children were observed. The sensitization rate was not affected by the pollen count in alder, grass, ragweed, and Japanese hop. In multivariable analysis, only alder sensitization was found to be associated with PFAS (odds ratio: 6.62, 95% confidence interval: 1.63-26.87, p = 0.008). In patients with PFAS in Busan and Tochigi, peach associated with birch allergen Bet v 1 was a causative food item for PFAS. Moreover, PFAS was associated with ragweed and Japanese hop pollen sensitization in Fukuoka. Regardless of pollen counts, alder pollen sensitization was associated with PFAS in children. Ragweed and Japanese hop pollen sensitization were associated with PFAS, particularly among children in southern Japan.

PILOT STUDY OF MODIFIED ROTATING ARM IMPACTOR FOR USE IN AEROBIOLOGICAL STUDIES

<h3>Introduction</h3> Utilized in aerobiological studies, the Rotarod Sampler (IQVIA) remains the gold standard in determining volumetric ambient airborne pollen concentration. However, utilization comes at the cost of high energy consumption, start-up and maintenance fees, and variable air patterns generated by rotating I-rods. We present a prototype to address the aforementioned issues: a battery-powered rotating arm impactor utilizing slides as opposed to rods. <h3>Methods</h3> The Rotorod Sampler Model 40 and prototype were situated in the same area and height, equipped with two rods and two slides coated with silicone grease, respectively. 7 atmospheric samples were collected and counted at various intervals over an 18-day period in June 2022, and directly compared. <h3>Results</h3> The prototype was created using 3D printing, with a 24 × 24 -millimeter exposure of each slide for sample collection. The prototype's speed was set at 10 revolutions per minute (RPM), while the Rotarod Sampler was set at 2400 rpm and utilized standard 31 × 1-millimeter sampler rods. Prototype battery needed to be replaced on days 2 and 18, and consequently may have impacted results. Mean pollen count and standard deviation of Rotarod Sampler was 124.2 and 40, and 23.4 and 10.6 for the prototype. The correlation coefficient was 0.61, signifying moderate positive association between pollen counts obtained from the Rotarod Sampler and prototype. <h3>Conclusion</h3> Though our prototype has a larger surface area, it collected significantly less pollen than the Rotarod Sampler. A moderate correlation between the two devices was observed, though increases in the RPM of the prototype should be considered for future evaluation.

Grass pollen exposure is associated with higher readmission rates for pediatric asthma.

Pediatric asthma hospital readmission is a burden on the individual and costly for Australian hospitals. Grass pollen's role, a known trigger for asthma admissions, is unexamined in readmissions. We examined the association between grass pollen and pediatric asthma readmission. The Victorian Admitted Episodes Dataset was used to identify all primary admissions with a principal diagnosis of asthma in children aged 2-18 years between 1997 and 2009. Readmissions were defined as subsequent admissions within 28 days of index admission discharge. Generalized additive models were used to assess associations between readmission, grass pollen season, and daily grass pollen counts, lagged and cumulative. Models were further stratified by sex and age group. Mean daily readmission was higher during grass pollen season than other times of the year, incidence rate ratio (IRR) 1.44 (95% CI, 1.03, 2.02) and for children aged 2-5 years, IRR 1.99 (1.26, 3.14). Same day grass pollen was nonlinearly associated with daily readmission for the 13-18 age group between 110 and 256 grains/m3 , p < .01. Lag 2 grass pollen was nonlinearly associated with daily readmissions overall (p=.03), boys (p=.01), and younger age groups 2-5 (p=.02) and 6-12 (p < .001). Grass pollen exposure was associated with higher readmission rates for pediatric asthma. Treatment plans prior to discharge could be implemented to reduce the likelihood of readmission by younger children during the pollen season.

Modeling past and future spatiotemporal distributions of airborne allergenic pollen across the contiguous United States.

Exposures to airborne allergenic pollen have been increasing under the influence of changing climate. A modeling system incorporating pollen emissions and atmospheric transport and fate processes has been developed and applied to simulate spatiotemporal distributions of two major aeroallergens, oak and ragweed pollens, across the contiguous United States (CONUS) for both historical (year 2004) and future (year 2047) conditions. The transport and fate of pollen presented here is simulated using our adapted version of the Community Multiscale Air Quality (CMAQ) model. Model performance was evaluated using observed pollen counts at monitor stations across the CONUS for 2004. Our analysis shows that there is encouraging consistency between observed seasonal mean concentrations and corresponding simulated seasonal mean concentrations (oak: Pearson = 0.35, ragweed: Pearson = 0.40), and that the model was able to capture the statistical patterns of observed pollen concentration distributions in 2004 for most of the pollen monitoring stations. Simulation of pollen levels for a future year (2047) considered conditions corresponding to the RCP8.5 scenario. Modeling results show substantial regional variability both in the magnitude and directionality of changes in pollen metrics. Ragweed pollen season is estimated to start earlier and last longer for all nine climate regions of the CONUS, with increasing average pollen concentrations in most regions. The timing and magnitude of oak pollen season vary across the nine climate regions, with the largest increases in pollen concentrations expected in the Northeast region.

Climate change and allergic diseases: An overview.

Climate change has been regarded as a threat to the human species on the earth. Greenhouse gasses are leading to increased temperatures on Earth besides impacting the humanity. These atmospheric conditions have shown to alter the release pattern of pollens and can change the timing and magnitude of pollen release with flowering plants. As pollen is responsible for respiratory allergies in humans, so climate change can adversely affect human health in susceptible individuals. In this review, we highlight the association between climate change, increased prevalence and severity of asthma, and related allergic diseases. Increased air pollution can alter the production of local and regional pollen. This altered pattern depends on bioclimatic parameters. As simulated with a pollen-release model and future bioclimatic data, warmer temperatures lead to an increased pollen count in some specific locations and for longer periods. Thus, anticipation of a future allergic disease burden can help public health agencies in planning to develop strategies in mitigating the unprecedented health challenges expected in future years.

Multiporate Pollen of Poaceae as Bioindicator of Environmental Stress: First Archaeobotanical Evidence from the Early–Middle Holocene Site of Takarkori in the Central Sahara

This paper reports on the most ancient unusual morphological trait of the apertures of Poaceae pollen found in archaeological layers. In Poaceae, high levels of hybridization, polyploidy, apomixis, and multiporate pollen are often related. Multiple genomes in polyploids are critical for the adaptation of plant species to stresses and could be revealed by anomalies in pollen development. Therefore, the paleoenvironmental research can gain great benefits from identifying polyploids in past contexts by observing anomalous pollen morphology during pollen counts. The occurrence of multiporate pollen in Poaceae has also been related to special features of the ecology of the species showing this anomaly, as well as to climatic and environmental stresses experienced by Poaceae living in a given region. Multiporate and bi- or tri-porate instead of monoporate pollen grains have been observed in samples taken from Takarkori rockshelter, an archaeological site in southwestern Libya (central Sahara) that has been occupied between ~10,200 and ~4650 cal BP. Multiporate pollen was found in organic sands and coprolites of ovicaprines. On the basis of archaeobotanical research, this work aims to investigate whether the presence of supernumerary pores in Poaceae pollen may be an effect of both climatic/hydrological changes and continued anthropogenic pressure on the wild grasses living in the region. The presence of multiporate pollen reveals that Poaceae that lived in central Sahara tackled several kinds of stress during the early and middle Holocene. The Takarkori pollen record suggests that climate change could have played a major role in the early Holocene, while human pressure became stronger during the middle Holocene. The change in environmental conditions determined adaptive responses of polyploid grasses even in the form of multiporate pollen.

PREVALENCE OF AIRBORNE POLLEN GRAINS AND FUNGAL SPORES IN A CITY OF THAR DESERT, INDIA

Monitoring of bioaerosols i.e., pollen grains and fungal spores, was undertaken for two consecutive years in a city of Thar Desert- Bikaner, using Gravity Slide Method. A total of 32 different pollen taxa were identified with Annual Pollen Integral (API) of 890 pollen grains per sq. cm in the first year and 906 pollen grains per sq. cm in the second year. The pollen count of non-arboreal plants was much more than that of the arboreal plants. The most prominent annual average pollen percentage was credited to Poaceae (25.91%), followed by Chenopodiaceae/Amaranthaceae (17.57%), Papilionaceae (7.86%) and Cyperaceae (5.95%) among non-arboreal plants: and to Prosopis juliflora (14.84%) amongst arboreal taxa. Two peak seasons were observed in both the years i.e., February to April and August to October for both pollen grains as well as fungal spores. 32 types of airborne fungal spores were reported from the atmosphere of Bikaner during the study. A total number of 6717 fungal spores per sq. cm were counted in the first year and 7117 spores per sq. cm in the second year. The commonest fungal spores encountered were of the species of Cladosporium, followed by Alternaria and Curvularia with annual mean percentage of 24.95%, 23.02% and 11.53 respectively.