2020
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Item Diverse organizations of actin and nuclei underpin the evolution of indeterminate growth in Chytridiomycota and Dikarya(Canadian Science Publishing, 2020-12-12) Dee, Jaclyn Marie; Berbee, MaryIndeterminate growth, as in the hyphae of the “Humongous Fungus” of Michigan requires sustained nuclear migration and cell wall remodeling. We compare actin organization and patterns of nuclear positioning among four distantly related, indeterminate species of phylum Chytridiomycota: Cladochytrium replicatum, Physocladia obscura, Nowakowskiella sp., and Polychytrium aggregatum. We combined light microscopy, nuclear staining with DAPI, and actin staining with rhodamine phalloidin to analyze actin distribution and nuclear migration during somatic growth in the four Chytridiomycota species. Actin formed plaques, filaments, cables and perinuclear shells in patterns that varied across the four species. All four species initiated indeterminate growth by extending branching, anucleate rhizomycelium,Item What are the genomic consequences for plastids in a mixotrophic orchid (Epipactis helleborine)?(Canadian Science Publishing, 2020-11-28) Valencia-D., Janice; Whitten, William Mark; Neubig, Kurt MThe chloroplast (plastid) controls carbon uptake, so its DNA sequence and function are highly conserved throughout the land plants. But for those that have alternative carbon supplies, the plastid genome is susceptible to suffer mutations in the photosynthetic genes and overall size reduction. Fully mycoheterotrophic plants receive organic carbon from their fungi partner, do not photosynthesize and also do not exhibit green coloration (or produce substantial quantities of chlorophyll). Epipactis helleborine (L.) Crantz exhibits all trophic modes from autotrophy to full mycoheterotrophy. Albinism is a stable condition in individuals of this species and does not prevent them from producing flowers and fruits. Here we assemble and compare the plastid genome of green and albino individuals. Our results show that there is still strong selective pressure in the plastid genome. Therefore, the few punctual differences among them, to our knowledge, do not affect any normal photosynthetic capability in the albino plant. These findings suggest that mutations or other genetically controlled processes in other genomes, or environmental conditions, are responsible for the phenotype.Item Phytohormone requirements of pollination drop secretion in Ginkgo biloba ovules(Canadian Science Publishing, 2020-12-18) Che, Wanqing; Mao, Danyang; Jiang, Bei; Lu, Zhaogeng; Wang, LiSecretion of the pollination drop (PD) plays a crucial role in the sexual reproduction of gymnosperms. However, the molecular mechanism regulating PD secretion has not been reported. In our study, we successfully constructed cDNA libraries in ovules between PD secretion and PD withdrawal stages, and identified 2975 differentially expressed genes (DEGs). These genes were involved in biosynthesis of secondary metabolites, fatty acid biosynthesis, fatty acid metabolism and hormone-related pathways. We especially identified DEGs related to jasmonic acid (JA) metabolism and signal transduction, including Gb_39942 (SDP1), Gb_03931 (OPR2), and Gb_18696 (4CLL4), which are all upregulated at the stage of PD secretion in Ginkgo biloba. Gb_17431 (TIF3B) and Gb_17432 (TIF9), which encode the negative regulator JAZ protein, are downregulated during this period. We also found that KO1 (Gb_05787 and Gb_38576) and GA20ox1 (Gb_16591), which are related to gibberellin (GA) synthesis, had increased expression, whereas Gb_17754, encoding the GA receptor GID1, is downregulated at the PD secretion. From these results, we predicted that JA and GA may play important roles in the regulation of PD secretion in G. biloba ovules.Item First report of Phyllactinia chubutiana, nom. cons. on Vallesia glabra (Apocynaceae) in Mexico(Canadian Science Publishing, 2020-12-18) Flix-Gastlum, Rubn; Leyva-Madrigal, Karla Yeriana; Quiroz-Figueroa, Francisco Roberto; Rodriguez-Mora, Norma; Maldonado-Mendoza, Ignacio Eduardo; Espinosa-Matas, Silvia; Mora-Romero, Guadalupe ArleneA new record of the powdery mildew Phyllactinia chubutiana, nom. cons. (= Oidium insolitum, Ovulariopsis insolita) was documented on pearl berry (Vallesia glabra). No teleomorph was observed. This novel record was identified as a member of Ovulariopsis based on the morphological characteristics of the anamorph (hyphae, conidiophores and conidia), and its hemi-endophytic mycelium in V. glabra correspond to P. chubutiana, nom. cons. A Phyllactinia-specific primer pair was designed for the ITS region of the nuclear rDNA. Phylogenetic analyses confirmed the identity of the powdery mildew specimens found in V. glabra in Sinaloa, Mexico. This is the first ever report of this powdery mildew in V. glabra, and the second report world-wide on a member of the Apocynaceae.Item Revisiting a DNA barcode survey of Haida Gwaii kelp: the quest for Eisenia arborea (Arthrothamnaceae, Laminariales)(Canadian Science Publishing, 2020-12-12) Bringloe, Trevor T; Brooks, Cody; Bruce, Meghann; Saunders, GaryEisenia arborea Areschoug is a temperate kelp first described from California, and commonly reported as far south as Mexico. Floristic surveys in cold-temperate waters of the Northeast Pacific, however, have revealed its presence on the Canadian archipelago of Haida Gwaii (at latitude 53.3799o N), last reported from the area in 2000 by Sloan and Bartier. Here, we present COI-5P data for E. arborea and confirm its presence at two sites on the west coast of Haida Gwaii in the years 2015 and 2018. These collections update a recently published list of genetically confirmed kelp species from Haida Gwaii. Our surveys suggest that northern populations of E. arborea are likely scattered throughout the western portions of the archipelago. The Haida Gwaii populations reported here represent potential monitoring sites for ecological and evolutionary investigations of E. arborea.Item Storage duration, light, temperature and salinity exposure influence germination of the glycophyte Rhanterium epapposum(Canadian Science Publishing, 2020-11-18) Bhatt, Arvind; Carn, Mara Mercedes; Gallacher, David; Souza-Filho, Paulo Roberto de MouraRegeneration of native species is the first priority for biodiversity conservation and restoration. To this end it is key to have seeds properly conserved in seed banks and knowledge of seed longevity and/or dormancy alleviation at different storage time intervals. In addition, understanding germination response of the stored seeds to environmental conditions improves the efficiency of restoration and rehabilitation projects. We investigated the influence of storage duration (1 to 5 years), light (0, 12 hours light), thermoperiod (night/day temperatures of 15/20 and 20/25C), and salinity (0, 100, 200 and 400 mM of NaCl) on seed germination of Rhanterium epapposum, a glycophytic species from the Arabian Peninsula. Seeds maintained viability after five years of storage indoors at room temperature. Three years of storage alleviated seed dormancy. Exposure to 12 hours light per day and 15/20C thermoperiods enhanced seed germination. Seeds were glycophytic; afteripened seeds exposed to salinity exhibited reduced germination that did not recover after salinity alleviation.Item Mycorrhizal colonisation in roots of Holcus lanatus (Yorkshire Fog) in a permanent pasture under conditions of reduced precipitation.(Canadian Science Publishing, 2020-11-18) Ayling, Sarah M; George, Belinda H.; Rogers, Jacqueline B.The UK climate is projected to become warmer, with more frequent hotter, drier summers. Many governments and international organisations are concerned about how climate change will affect food production and security. Mycorrhizal fungi are an essential part of agricultural systems and yet little is known about how climate change will affect mycorrhizal fungi. We investigated the effect of reduced precipitation on levels of arbuscular mycorrhizal (AM) colonisation in the top 10 cm of soil in the grass Holcus lanatus L. (Yorkshire Fog) in a permanent pasture in South Gloucestershire, UK. Incident rainfall was reduced, by approximately 50 %, using clear gutters supported on steel frames. Over three growing seasons we observed little difference in levels of AM colonisation and numbers of intra-root fungal structures between the roots of H. lanatus grown with reduced or full incident rainfall. Time of year when water stress occurred had a stronger effect on levels of colonisation than the absolute amount of precipitation received. In H. lanatus, growing in a permanent pasture, levels of AM colonisation were around 40 - 50%, across a range of precipitation, from 18% above to 36% below the long-term average. The results highlighted the complex relationship between mycorrhizal fungi, host plant and abiotic stress.Item Root Growth Phenology, Anatomy, and Morphology among root orders in Vaccinium macrocarpon Ait.(Canadian Science Publishing, 2020-11-18) Atucha, Amaya; Workmaster, Beth Ann; Bolivar-Medina, JennyUnderstanding mechanisms controlling plant growth is essential to maintain and increase productivity in managed ecosystems. However, the lack of information on below ground growth compared to above ground growth limits our ability to adjust crop management practices under changing climate. This study examines seasonal fine-root growth and its spatial distribution through the soil profile across the growing season, and the anatomical and morphological traits of roots according to their branching order in Vaccinium macrocarpon Ait. Root production followed a unimodal curve, with one marked flush of root growth starting at bloom, with a peak at the end of fruit maturation. Root vertical distribution concentrated in the upper 5 cm of soil depth, accounting for over 50% of new roots produced during the study. Root anatomy and morphology was related to root function, as the first three root orders had intact cortex and epidermis and high mycorrhizal colonization indicative of absorptive function, while orders 5th and higher had secondary development and presence of a cambium cork layer indicative of translocation. Our study highlights the importance of examining timing of root growth and root traits by root order and its implications for the timing of fertilization and other practices in managed ecosystems.Item Genome-wide identification and expression profiling of the SPL family genes in wheat(Canadian Science Publishing, 2020-11-01) Guo, Fuye; Lu, Qiuwei; Cang, JingThe SQUAMOSA promoter-binding protein-like (SPL) proteins constitute a family of plant-specific transcription factors that play a vital role in plant development. Wheat (Triticum aestivum, AABBDD) is universally well-known as a cash crop; however, the SPLs of this important crop have not been systematically investigated as yet. In the current study, we conducted a genome-wide survey in wheat and found 56 SPL genes belonging to 19 homologous groups. SPLs were divided into 7 classes by phylogenetic tree analyses. We mapped these genes on to the wheat chromosomes and examined their structures and conserved motifs. Moreover, we performed a synteny analysis on wheat, and summarized the SPL family as well as the evolutionary relationships between SPLs. Thereafter, we compared the expression patterns of wheat SPLs under different conditions, thereby confirming that SPLs play an important role in spike development. To conclude, the SPLs in triplets have analogous structures and similar expression patterns. The three-pair triplet response to jasmonic acid (JA) and abscisic acid (ABA) was determined by quantitative real-time polymerase chain reaction (RT-qPCR). This work provides a comprehensive understanding of the SPL gene family in wheat. Our investigation of the wheat SPL gene family provides a starting point for additional functional studies of these significant transcription factors in wheat.Item Comparative morphology and ontogenetic patterns of Bdallophytum species (Cytinaceae, Malvales): insight into the biology of an endoparasitic genus(Canadian Science Publishing, 2020-11-23) Rios-Carrasco, Sandra; VZQUEZ-SANTANA, SONIACytinaceae are root endoparasitic plants with only three genera. Their biology is largely unknown, and most knowledge of the family is based on the Old World genus, Cytinus. Here, we studied all three species of the New World Bdallophytum from Mexico. We describe their morphoanatomy, floral development, and embryology, highlighting the unique traits of Bdallophytum compared with two other genera of the family and members of Malvales. Both B. americanum and B. andrieuxii are dioecious, while B. oxylepis is gynomonoecious. The floral size and the number of floral organs vary within and among species, which appears common in Cytinaceae. The flowers of Bdallophytum exhibit synorganization in sexual organs, a synandrium in male flowers, and a gynostemium in bisexual flowers of B. oxylepis. Unisexual and bisexual flowers are zygomorphic at the early developmental stages. The unisexual flowers become actinomorphic in later development, while the bisexual flowers of B. oxylepis remain zygomorphic. The androecium of Bdallophytum has key traits shared with some Malvales, such as the fused filaments in Malvaceae and Sarcolaenaceae and the connective appendage shared with Dipterocarpaceae. Our results suggest that a unitegmic ovule is a unique trait for Bdallophytum. This is proposed here as a putative synapomorphy for Bdallophytum.Item Nutritional composition of saskatoonberries - A review(Canadian Science Publishing, 2020-10-28) Fang, JimSaskatoonberry (Amelanchier alnifolia Nutt., Rosaceae), also known as serviceberry, is a deciduous shrub native to the northern prairies and plains of North America. Saskatoonberries are an excellent source of typical health-promoting nutrients such as fibers, minerals (manganese, calcium, potassium, magnesium, iron) and vitamins (tocopherol, pyridoxine, riboflavin, ascorbic acid, riboflavin, thiamin, pantothenic acid). Saskatoonberries are rich in health-promoting phytochemical compounds, mainly anthocyanins (cyanidin-3-galactoside, cyanidin-3-glucoside, cyanidin-3-arabinoside, and cyanidin-3-xyloside), flavonols (Quercetin-3-galactoside, quercetin-3-glucoside, quercetin-3-arabinoglucoside, quercetin-3-arabinoside, quercetin-3-rutinoside, and quercetin-3-xyloside), proanthocyanidins (A- and B-type procyanidins with different degrees of polymerization), phenolic acids, and volatile components. Saskatoonberry seed oil contains 99 g/100g of total fat and out of which 9.8 g/100g is present as saturated fat, 31 g/100g as monounsaturated fat and 58 g/100g as cis-cis polyunsaturated fat. Saskatoonberry seed oil contains approximately 10 g/kg of phytosterols in total (β-sitosterol, Δ5-avenasterol, campesterol and stigmasterol). In mature (purple) saskatoonberries, the content of cyanogenic compounds amygdalin and prunasin were found to be 42-118 mg/kg and 5-17 mg/kg of fresh weight, respectively. These compounds are confined to seeds which greatly slows down their absorption when saskatoon fruits are consumed. In summary, as an emerging functional food, saskatoonberries are an excellent source of minerals, fiber and phenolic compounds, such as anthocyanins and proanthocyanidins.Item Analyse morphologique et taxonomique du complexe Quercus faginea (Fagaceae) en Algérie(Canadian Science Publishing, 2020-08-12) Aissi, Abdeldjalil; BEGHAMI, Yassine; Lepais, Olivier; Vela, ErrolLa systmatique de Quercus faginea Lam. (s.l) (Fagaceae) reste encore indfinie, d’autant plus qu’elle s’hybride avec d’autres espces et qu’elle est polymorphe. Quatre sous-espces ont t identifies et prsentement reconnues en pninsule ibrique et au Maroc, or, les donnes disponibles ne permettent pas de trancher entre les taxons prsents en Algrie. Pour remdier au manque de donnes ncessaires, une analyse morphologique et taxonomique de treize populations du complexe dans le pays a t effectue. Dans chacune, vingt feuilles et vingt bourgeons sur dix arbres matures ont t prlevs pour une description dtaille de 23 traits morphologiques. L’ACM (analyse des correspondances multiples) et la CAH (classification ascendante hirarchique) ont t utilises pour analyser les donnes et identifier des groupes homognes. Une variabilit significative intra et inter-populationnelle est remarquable, avec une taille des feuilles qui tend se diminuer en allant de l’est vers l’ouest et du nord au sud du pays. Cette variabilit ne permet pas, elle seule, de diffrentier entre les populations tudies, en revanche, les traits lis la forme du limbe et aux types du tomentum sur la feuille s’avrent plus utiles. Cette tude confirme que le complexe Q. faginea Lam. est reprsent en Algrie par deux espces : Quercus canariensis Willd. et Q. faginea Lam., lui-mme reprsent par deux taxons, subsp. faginea et subsp. broteroi. The systematics of Quercus faginea Lam. (s.l) (Fagaceae) remains obscure, as it tends to crossbreed with other species and show signs of polymorphism. Four subspecies were identified and currently recognized in the Iberian Peninsula and Morocco. However, the literature to date does not allow the distinction between the taxa present in Algeria. To remedy the lack of required data, morphological and taxonomic analysis of thirteen tree populations has been carried out in the country. In the process, twenty leaves and twenty buds from ten mature trees were collected at each population to produce a more detailed description of 23 particular morphological traits. MCA (multiple correspondence analysis) and AHC (agglomerative hierarchical clustering) were used to analyze the data and to identify homogeneous groups. The results obtained show high intra and inter-population variability, with leaf size diminishing from east to west and from north to south. Though the findings were remarkable, they alone could not be used to differentiate between populations under examination; the traits relating to limb shape and indumentum type on the leaf prove to be more useful. It is clear from this study that the Q. faginea Lam. group in Algeria is represented by two species: Quercus canariensis Willd. and Q. faginea Lam., the latter being represented by two taxa: subsp. faginea and subsp. broteroiItem Argon-ion beam induced mutants of the ectomycorrhizal agaricomycete Tricholoma matsutake defective in β-1,4 endoglucanase activity promote the seedling growth of Pinus densiflora in vitro(Canadian Science Publishing, 2020-10-07) Murata, Hitoshi; Nakano, Shota; Yamanaka, Takashi; Shimokawa, Tomoko; Abe, Tomoko; Ichida, Hiroyuki; Hayashi, Yoriko; Tahara, KoTricholoma matsutake is an ectomycorrhizal agaricomycete that produces the prized matsutake mushroom in conifer forests. Here, we isolated mutants generated by the argon-ion beam irradiation of T. matsutake NBRC 33136, designated as Ar 5002 and Ar 5012, which are defective in β-1,4 endoglucanase activity, that promoted the above- and below-ground growth of the symbiotic partner Pinus densiflora in vitro compared with the control. Pine seedlings associated with Ar 5002, compared with NBRC 33136, had significantly higher above-ground dry weights and significantly greater plant growth, while those associated with Ar 5012 had significantly higher above- and below-ground dry weights. There were no significant differences between the numbers of mycorrhizal root-tips synthesized by the wild-type and mutants, indicating that β-1,4 endoglucanase did not influence the mycorrhization of T. matsutake. In Ar 5002- and Ar 5012-inoculated seedlings, the Hartig nets resembled those of NBRC 33136-inoculated seedlings. The data suggest that T. matsutake lacking β-1,4 endoglucanase activity confer beneficial effects on P. densiflora growth. Further studies are necessary to determine whether the symbiotic relationship could be strengthened by such a mutated fungal trait.Item Addition of methyl jasmonate and rutin hydrate at harvest time elicits lipid production in Scenedesmus(Canadian Science Publishing, 2020-10-21) Kaushik, Nutan; Dhup, Saumya; Jamsheer K, MuhammedMicroalgae are a sustainable source of lipids for industrial applications. In this study, we tested the effect of three chemical elicitors [chitosan, methyl jasmonate (MeJA), and flavonoids] on lipid accumulation in the microalga Scenedesmus. We analyzed the effect of different concentrations of these elicitors at different time points on growth rate and lipid production. We found that these elicitors did not have an adverse effect on the growth rate of Scenedesmus at different time points, by comparison with their respective controls. Among the three elicitors, MeJA at a low concentration (25 μL/L) was found to be effective at enhancing the lipid production in Scenedesmus when added at the time of harvest and allowed to react for 12 h, whereas flavonoid treatment, specifically at 0.5 mg/L, enhanced lipid production after 24 h. Fatty acid methyl ester analysis by GC–MS revealed no difference in lipid profile before or after chemical induction. Taken together, this comparative analysis highlights the potential of MeJA at a low concentrations to be effective at improving lipid productivity without altering the growth rate in Scenedesmus.Item Long-term responses of forest-floor bryophytes buried by tephra in the 1980 eruption of Mount St. Helens(Canadian Science Publishing, 2020-10-17) Waxwing, Stella Rose; Fischer, Dylan; Antos, Joseph A.; Biswas, Abir; Zobel, Donald B.Responses in bryophyte communities following volcanic disturbance are not well understood. The eruption of Mount St. Helens on 18 May 1980 deposited large amounts of tephra (aerially transported volcanic ejecta) on nearby forests in southwestern Washington and presented an opportunity to examine bryophyte succession, with a focus on mosses. We examined changes in moss community over 36 years following this disturbance, using permanent plots located in old-growth conifer forests. We used an experimental design where we removed the tephra from some of the plots shortly after the eruption. Initial dramatic decreases in total bryophyte cover, moss species richness, and diversity in plots with intact tephra were followed by increases by 2016. Community profiles also shifted through time but were somewhat site-specific. Moss community change was related to changes in vascular plant species and was driven by changes in a few key moss species with distinct growth strategies. Bryophyte change through time was most pronounced in the plots buried by tephra, but differed among sites. Overall, total bryophyte cover had recovered, reaching our estimate of pre-disturbance levels at all sites after 36 years, but trajectories of change differed among sites, demonstrating the importance of idiosyncratic site factors and the dynamics of the vascular plant species.Item Genome size variation in natural populations of wild potato species from west Argentina(Canadian Science Publishing, 2020-10-06) Kozub, Perla Carolina; Masuelli, Ricardo; Marfil, Carlos FedericoWild potato species (Solanum, section Petota) have great ecological adaptability and represent essential genetic resources for the improvement of the third most important food crop worldwide. From more than 100 species described for this section, the genome size has been established for only 12. The aims of this work were to: contribute data on the C-values for Solanum species; assess the degree of interspecific and intraspecific genome size variation; investigate correlations between genome size and bioclimatic variables; and determine whether the data for genome size are helpful for delineating taxa. The DNA contents of 97 genotypes from 28 populations and two accessions of seven wild potato species, including diploids, triploids, and tetraploids, were measured by flow cytometry. Statistical genome size differences within and among species were found. The natural interploidal hybrid Solanum × rechei had the highest intraspecific genome size variation. The tetraploid S. acaule presented the smallest monoploid genome size (0.72 pg), whereas the triploid cytotype of S. microdontum was the largest (0.82 pg). Correlations among bioclimatic and geographic variables and genome size were found in most species. The roles of hybridisation and polyploidisation events on genome size variability are discussed.Item Ovule-gall stimulating a large fake fruit on Miconia chamissois Naudin (Melastomataceae): a structural overview(Canadian Science Publishing, 2020-10-02) Bomfim, Phabliny; Coelho Kuster, Vincius; Caetano, Ana Paula Souza; Goncalves, Letcia; Oliveira, DenisThe developmental processes of galls are better known when induced on vegetative organs, while they have hardly ever been described for reproductive ones. Herein, galls induced by Allorhogas uberlandiensis (Hymenoptera) on ovules of Miconia chamissois (Melastomataceae) were analyzed in terms of morphological, anatomical, histochemical and cytological characteristics. Galls are induced on the ovules before fertilization, acting as a physiological seed. Therefore, the ovary grows and develops into a fruit-like gall. The ovule-galls are on average 20 times larger than the seeds, and fruit-like gall volume is on average 5.4 times larger than that of mature fruits. These are related to cell hypertrophy and tissue hyperplasia in the host organ. There is a typical nutritive tissue formation in the ovule-gall with lipid, protein and pectin storage, as well as a storage tissue close to the epidermis. This nutritive tissue shows a smooth endoplasmic reticulum, multivesicular bodies and mitochondria-rich cells. After gall induction, all the ovules degenerate and ovary and hypanthium hypertrophy to form the fruit-like gall. The fruit-like galls form a physical barrier blocking the anthesis, preventing fertilization and keeping only ovule-galls. Our study shows that the A. uberlandensis galling insect may reduce the reproductive success of Miconia chamissois, thus acting as a biological control agent for this host plant population.Item Morphoanatomical and biochemical changes in Zeyheria tuberculosa exposed to glyphosate drift(Canadian Science Publishing, 2020-10-01) de Freitas-Silva, Larisse; Castro, Naila Diniz; Campos da Silva, LuzimarWhen glyphosate is applied, some of the herbicide can reach adjacent vegetation and impact the natural plant community structure and diversity over the long term. This study evaluated the response of leaves of Zeyheria tuberculosa (Vell.) Bureau ex Verl. (Bignoniaceae) to the herbicide glyphosate. Plants were exposed to aerial applications of the herbicide at concentrations of 0, 360, 720, 1080, or 1440 g acid equivalent (a.e.)·ha 1. The concentrations of shikimic acid in leaves of the herbicide-treated plants were always higher than the controls. Visual symptoms became apparent four days after the application of 720 g·ha 1. Glyphosate induced an increase in malondialdehyde in Z. tuberculosa leaves. The lowest levels of chlorophyll a were found for the three last applied doses, and protein content decreased with the glyphosate treatment. Necrosis was observed on the epidermis and in the mesophyll. Glandular trichomes were also plasmolyzed. On the midrib there was plasmolysis of non-lignified cells. Micromorphologically, there were cell plasmolysis and rupture of glandular trichomes. Thus, glyphosate is phytotoxic to Z. tuberculosa by causing biochemical, anatomical, and morphological changes. The morphoanatomical injuries found on Z. tuberculosa were severe, suggesting that the presence of glyphosate can irreversibly affect this species and compromise its survival.Item Effect of seed size on germination in three species from arid Arabian deserts(Canadian Science Publishing, 2020-09-25) Gairola, Sanjay; Mahmoud, Tamer; Shabana, Hatem A.; AlKetbi, Asma; Phartyal, Shyam S.In many species, seeds with different sizes show diverse responses in their requirements for temperature and light for optimal germination. In this study, the effect of seed size (i.e., small and large) on germination was tested in seeds of Brassica tournefortii Gouan, Lotus garcinii DC., and Salvadora persica L. from arid Arabian Desert habitats. The mean seed size of all three study species differs significantly between small and large-sized seeds. Differences were observed in seed germination between large and small seeds of B. tournefortii and L. garcinii. We found that the large seeds of B. tournefortii and L. garcinii showed a higher germination percentage at all tested temperatures than that displayed by the small seeds. However, both small and large seeds of S. persica germinated equally (100%) well under all tested incubation conditions. Our results show significant differences in germination percentage between the small and large seeds of B. tournefortii at 25/35°C under a 12 h light regime. However, seeds of L. garcinii showed a significant difference in germination percentage at low temperatures (15/25°C) under a 12 h light regime.Item Dissimilar biodiversity data sets yield congruent patterns and inference in lichens(Canadian Science Publishing, 2020-08-21) Lendemer, James C.; Coyle, Jessica R.Large-scale efforts to aggregate and promote the re-use of biodiversity data are leading to novel insights into biogeography and macroecology. However, secondary analyses must account for the tradeoffs and limitations of the original studies. Studies of speciose and taxonomically complex groups often utilize morphospecies or functional subsets as proxies, potentially complicating data re-use. We evaluated whether lichen biodiversity patterns are robust to differences in sampling methodology, utilizing parallel analyses to compare species richness, regional species pool variation, species probabilities of occurrence, and correlation of those three with environmental variables in data sets that cover the same geographic region. Our analyses revealed that, although individual species distributions sometimes differed in idiosyncratic ways, inference based on the aggregated response of multiple species was generally robust across the two datasets, despite differences in observer expertise and functional and taxonomic scope. This suggests that biodiversity data assembled from disparate sources could be used to evaluate biogeographical and macroecological hypotheses in understudied groups such as lichens, particularly at larger spatial scales.