Molecular study of two distinct phytoplasma species associated with streak yellows of date palm in Iran

A disease with symptoms similar to palm lethal yellowing was noticed in the early 2013 in Khuzestan Province (Iran) in date palm (Phoenix dactylifera). Infected trees displaying symptoms of streak yellows and varied in the incidence and severity of yellowing. A study was initiated to determine whether phytoplasma was the causal agent. Polymerase chain reaction–restriction fragment length polymorphism (PCR‐RFLP) methods using universal phytoplasma primers pairs R16mF1/mR1 and M1/M2 were employed to detect putative phytoplasma(s) associated with date palm trees. Nested PCR using universal primers revealed that 40 out of 53 trees were positive for phytoplasma while asymptomatic date palms from another location (controls) tested negative. RFLP analyses and DNA sequencing of 16S rDNA indicated that the presence of two different phytoplasmas most closely related to clover proliferation (CP) phytoplasma (group 16SrVI) and ash yellows (AY) phytoplasma (group 16SrVII). Sequence analysis confirmed that palm streak yellows phytoplasmas in each group were uniform and to be phylogenetically closest to “CandidatusP. fraxini” (MF374755) and “Ca. P. trifolii” isolate Rus‐CP361Fc1 (KX773529). Result of RFLP analysis of secA gene of positive samples using TruI and TaqI endonuclease is in agreement with rDNA analysis. On this basis, both strains were classified as members of subgroups 16SrVI‐A and 16SrVII‐A. This is the first report of a phytoplasma related to CP and AY phytoplasma causing date palm yellows disease symptoms.     

The palm has its time: an Ethnoecology ofSabal uresana in Sonora,Mexico

Participant observation and formal interviews were used to learn what local people understood of palm natural history and how palms were managed. Ecological and ethnographic methods were combined to assess traditional ecological knowledge (TEK) and traditional resource management (TRM). Palm workers understood TEK and TRM for palms. This knowledge was not general in the population, however. Residence, harvester status, and gender were strongly correlated with TEK and TRM. Harvest practices included limiting access, “sparing,” controlling harvest times and levels, and choice of leaf age and palm size. “Alpha” management is proposed as practices which maintain populations long-term. In this case, sparing was the single most important practice. “Beta” management is shorter term and important for obtaining good quality product in sufficient quantities. Although the impacts are more subtle, it can affect population structure over time. This study provides one prototype for identifying practices which function as de facto conservation traditions for wild-harvested species.     

Genetic-gonadal-genitals sex (3G-sex) and the misconception of brain and gender,or, why 3G-males and 3G-females have intersex brain and intersex gender

The categorization of individuals as “male” or “female” is based on chromosome complement and gonadal and genital phenotype. This combined genetic-gonadal-genitals sex, here referred to as 3G-sex, is internally consistent in ~99% of humans (i.e., one has either the “female” form at all levels, or the “male” form at all levels). About 1% of the human population is identified as “intersex” because of either having an intermediate form at one or more levels, or having the “male” form at some levels and the “female” form at other levels. These two types of “intersex” reflect the facts, respectively, that the different levels of 3G-sex are not completely dimorphic nor perfectly consistent. Using 3G-sex as a model to understand sex differences in other domains (e.g., brain, behavior) leads to the erroneous assumption that sex differences in these other domains are also highly dimorphic and highly consistent. But parallel lines of research have led to the conclusion that sex differences in the brain and in behavior, cognition, personality, and other gender characteristics are for the most part not dimorphic and not internally consistent (i.e., having one brain/gender characteristic with the “male” form is not a reliable predictor for the form of other brain/gender characteristics). Therefore although only ~1% percent of humans are 3G-“intersex”, when it comes to brain and gender, we all have an intersex gender (i.e., an array of masculine and feminine traits) and an intersex brain (a mosaic of “male” and “female” brain characteristics).     

Genetic analysis of the slow-melting flesh character in peach

The slow-melting flesh (SMF) trait in peach [Prunus persica (L.) Batsch] defines a slower process of postharvest fruit-softening than the prevalent melting flesh (MF) types. This gives a longer shelf life and a delayed harvest-time resulting in better fruit quality. Unlike other known fruit texture traits, SMF is difficult to measure and has a complex inheritance. We examined this character over 2 years in the offspring of two crosses, both with “Big Top,” an SMF nectarine, as the female parent, and with a melting flesh (MF) nectarine as the male parent (“Armking” and “Nectaross”). Following harvest, a texturometer was used to provide a textural profile analysis, and fruit firmness evolution was measured with a penetrometer over a period of 5 days’ storage at 20 °C. Linkage maps were constructed with a high-density SNP chip, and a phenotype-genotype analysis allowed the detection of three independent genomic regions where most QTLs (quantitative trait loci) were located. Two of these, on linkage groups 4 and 5, explained the variability for two characters—maturity date and firmness loss—that is, the QTL on linkage group 4 found in the MF parents and that on linkage group 5 in Big Top. A third region on linkage group 6, which identified a QTL for maturity date only in Armking, has no apparent association to the softening process. The relationship between maturity date and fruit-firmness loss and a hypothesis on the inheritance of the SMF character are discussed.     

Identification and sequencing of Date-SRY Gene: A novel tool for sex determination of date palm (Phoenix dactylifera L.)

Dioecism has always been an issue in many plant species with its numerous disadvantages, especially in woody trees such as date palms. As one of the most important crops in the Middle Eastern countries, researchers are having problems identifying of sex of the plant in its early stages of development. Hence, proper population stands in the male: female ratio for maintenance is almost impossible in the field for better production. In this study, sex determination of date palm (Phoenix dactilyfera L.) were identified in regions of the Y chromosome (Date-SRY) gene, the pivotal gene that initiates sex determination, using a new technique and thus an economically desirable objective, which will significantly impact profits in seed based cultivations. Partial sequences of the Date-SRY were taken and amplified by nested polymerase chain reaction (PCR). According to the results, the exact sex of date palm was identified in all the tested plants, while amplified regions of the Date-SRY gene closely matched with the human and papaya sequences. In addition, a primer pair was designed to amplify the sequences of the SRY-date gene with confidence that it will identify male date palms. These primer sequences include SRY-date Forward 5′- cggccctctaagtatctgtgcgcaacg-3′ (SRY-date F) and the SRY-date Reverse 5′- gtttgcacttcgaagcagag-3′ (SRY-date R). The complete sequence of the DNA has been registered and deposited in GenBank (BankIt1598036 DPSRY1 KC577225 thenKJ873056).     

Date Palm Agrobiodiversity (<Emphasis Type="Italic">Phoenix dactylifera</Emphasis> L.) in Siwa Oasis,Egypt: Combining Ethnography,Morphometry, and Genetics

We evaluate date palm (Phoenix dactylifera L.) agrobiodiversity of Siwa oasis, Egypt, located at the crossroads of ancient Trans-Saharan routes, focusing on diversity both as expressed and maintained by the folk categorization system of Siwa inhabitants (through an ethnographic analysis) and as described by genetic sciences and a morphometric tool based on size and geometry of seeds. We verified that some named types are true cultivars, sharing not only a formal identity, important for Isiwan people, but also a genetic identity. However, we also confirm the existence of “ethnovarieties,” i.e., voluntary collections of multiple clones sharing phenotypic characteristics with the same local name, suggesting the genetic richness is higher than the apparent agrobiodiversity estimated by a superficial ethnobotanical approach. Finally, our research offers new insights on the relative importance of feral and cultivated date palms.     

Behavior of males in a reproductive aggregation of the banded demoiselle Calopteryx splendens (Insecta, Odonata)

The view according to which damselfly males practice two alternative reproductive tactics of access to females is critically discussed. It is widely accepted that some males (“territorial” ones) have priority as potential female partners, while others (“sneakers” or “wanderers”) are incapable of retaining an individual territory. They have a chance of mating only by intruding briefly into the area defended by a “territorial” male when a female is present there. Thus, the tactics of a “territorial” male consists in waiting for a female in its territory and copulating with it “by agreement,” whereas non-territorial males resort to forced copulations. By observation of individually marked males (48 out of 118) it was shown that every male could be regarded as “territorial” during a certain period and as a “wanderer” before and after it. Thus, no correlation between the modes of space use by a male (residence/mobility) and the characters of its external morphology and/or signal behavior appears to be possible in principle. According to the data obtained, a more plausible explanation is that the female chooses not the male but the best area for oviposition. In addition, it was ascertained that adherence to forced copulations cannot constitute successful “tactics” since they rarely result in insemination, neither by “territorial” nor “non-territorial” males. In other words, we are dealing not with certain alternative tactics (i.e., specialized adaptive mechanisms that have evolved in the species) but simply with the results of different sets of circumstances at a given moment.     

Differences in invasiveness between two cryptic species of the coconut beetle <Emphasis Type="Italic">Brontispa longissima</Emphasis> in Timor-Leste

Brontispa longissima (Coleoptera: Chrysomelidae) is a serious pest of coconut palm, and the species contains two cryptic species: the “Asian clade” is distributed over a wide area, including Asia and the Pacific region, whereas the “Pacific clade” is distributed in a limited area. Recent invasions and outbreaks have only been reported for the Asian clade, suggesting that invasive ability may differ between the clades. To reveal differences in invasiveness, we investigated the damage potential on coconut palm and range expansion of the two clades in Timor-Leste, where both clades are present. Distribution of the clades and of severely damaged trees indicated that range expansion and outbreaks have occurred for the Asian clade but not for the Pacific clade. The Asian clade attacked trees taller than 10 m, whereas the Pacific clade seldom attacked these trees. The preference for the taller trees, which are more abundant, can facilitate range expansion and outbreaks of the Asian clade. The beetle has spread through areas where coconut palms are continuously available, but have not expanded their distribution where coconut palms are separated by large gaps. This indicates that areas free of coconut palm could serve as buffer zones to prevent spread of this beetle.     

Beta diversity and oligarchic dominance in the tropical forests of Southern Costa Rica

Recent studies have reported a consistent pattern of strong dominance of a small subset of tree species in neotropical forests. These species have been called “hyperdominant” at large geographical scales and “oligarchs” at regional‐landscape scales when being abundant and frequent. Forest community assembly is shaped by environmental factors and stochastic processes, but so far the contribution of oligarchic species to the variation of community composition (i.e., beta diversity) remains poorly known. To that end, we established 20.1‐ha plots, that is, five sites with four forest types (ridge, slope and ravine primary forest, and secondary forest) per site, in humid lowland tropical forests of southwestern Costa Rica to (a) investigate how community composition responds to differences in topography, successional stage, and distance among plots for different groups of species (all, oligarch, common and rare/very rare species) and (b) identify oligarch species characterizing changes in community composition among forest types. From a total of 485 species of trees, lianas and palms recorded in this study only 27 species (i.e., 6%) were nominated as oligarch species. Oligarch species accounted for 37% of all recorded individuals and were present in at least half of the plots. Plant community composition significantly differed among forest types, thus contributing to beta diversity at the landscape scale. Oligarch species was the component best explained by geographical and topographic variables, allowing a confident characterization of the beta diversity among tropical lowland forest stands. Abstract in Spanish is available with online material.     

Lethal yellowing-type diseases of palms associated with phytoplasmas newly identified in Florida, USA

A nested polymerase chain reaction (PCR) assay was used to detect phytoplasmas in stem tissues from declining silver date ( Phoenix sylvestris ), Canary Island date ( Phoenix canariensis ), edible date ( Phoenix dactylifera ), Queen ( Syagrus romanozoffiana ) and Mexican fan ( Washingtonia robusta ) palms, all displaying symptoms similar to lethal yellowing (LY) disease, in a tri-county region of west central Florida. Restriction fragment length polymorphism analysis or sequencing of PCR-amplified rDNA products (1.6 kb) identified three distinct group 16SrIV phytoplasma strains among 38 infected palms. Most palms (86.8%) contained Texas Phoenix decline (TPD) phytoplasma, a subgroup 16SrIV-D strain, while two P. canariensis harboured palm LY phytoplasma, a subgroup 16SrIV-A strain. A novel phytoplasma, initially detected in W. robusta and tentatively classified as a subgroup 16SrIV-F strain, also occurred with LY phytoplasma as mixed infections in two P. dactylifera palms. Collectively, these findings extend the known geographic range of TPD in the USA to include Florida and the listing of TPD-susceptible palm species to include P. dactylifera , P. sylvestris and S. romanozoffiana . Moreover, discovery of a novel subgroup 16SrIV-F strain in W. robusta adds to the list of phytoplasma host palm species and complexity of phytoplasma-vector-palm pathosystems newly identified in the west central region of the state. The emergence of new lethal disease of palms beyond southern subtropical region of the state is unprecedented but follows similar developments in other regions where LY is known to occur.     

Benthic indicators of sediment quality associated with run-of-river reservoirs

Freshwater ecosystems have been fragmented by the construction of large numbers of dams. In addition to disruption of ecological continuity and physical disturbance downstream, accumulation of large amounts of sediment within run-of-river reservoirs constitutes a latent ecotoxic risk to aquatic communities. To date, run-of-river reservoirs and ecotoxic risks associated with contaminated sediment to the biodiversity and functioning of such systems are little studied. Therefore, the main objective of this study was to describe macroinvertebrate assemblages, and the functioning of these systems, and to propose indicators of sediment contamination to integrate in in-situ risk assessment methodology. To identify specific assemblages of run-of-river reservoirs, we first compared macroinvertebrate assemblages and their biotrait profiles (i.e. from a database of biological and ecological traits) in reservoirs (n = 6) and associated river sites (upstream and downstream of dams). Then, we compared responses of assemblages and biotrait profiles to sediment contamination of the banks and channels of reservoirs to select the most useful spatial scale to identify sediment contamination. Nineteen indicator taxa were observed to be specifically associated with channel habitats of reservoirs. Among these, the abundance of three taxa (Tanypodinae (Diptera), Ephemerella (Ephemeroptera) and Atherix (Diptera)) revealed the effect of metal sediment contamination. “Between-reservoirs” differences in their biotrait profile were found along the contamination gradient, with a shift of communities’ composition and functionality, and an increase in functional similarity. Many traits (response traits), for example “maximum size”, “transverse distribution”, “substrate preferences”, “saprobity”, “temperature”, “resistance forms”, and “locomotion”, were specifically linked to contamination of sediments by metals. This study indicates how sediment contamination can change the structural and functional composition of run-of-river reservoir assemblages. Indicator taxa and response traits identified in this study could improve current risk assessment methodology and potentially enable prediction of the risks of contaminated sediments stored in reservoirs in downstream ecosystems.     

Susceptibility of two Coconut Pests,Oryctes rhinoceros [Col.: Scarabaeidae] andTirathaba rufivena [Lep.: Pyralidae], to the entomoparasitic nematodeSteinernema feltiae [= Neoaplectana carpocapsae]

Bioassay indicated that 1 st instar larvae ofOryctes rhinoceros are resistant to infections by the nematodeSteinernema feltiae (estimated LD₅₀: 90 nematodes) but thatTirathaba rufivena larvae larger than 15 mm are highly susceptible (estimated LD₅₀: 3 nematodes). The “All” strain and the “mexican” strain ofS. feltiae gave very similar responses. In a field trial 300,000 nematodes were sprayed on each of 25 palms to controlT. rufivena. Although some mortality from nematodes was observed, the treatment failed to reduce the pest population significantly.     

Insight into Date Palm Diversity: Genetic and Morphological Investigations

Date palm (Phoenix dactylifera) is an important crop plant both from nutritional and economic points of view. The assessment of genetic diversity and population differentiation of date palms are evaluative for its dynamic conservation and sustainable utilization of its genetic diversity. Estimates of genetic diversity based on molecular markers and fruit characteristics were performed in samples of 23 date palms growing in Ahvaz city (Khuzestan province of Iran). Clustering based on fruit morphological features separated the cultivars in different groups. These cultivars differed significantly in morphological features (P =?0.001). Start codon targeted (SCoT) polymorphism markers revealed a good level of genetic variability (10.17 to 45.76%) in these cultivars. Moreover, STRUCTURE analysis revealed the presence of within-population genetic variability. Analysis of molecular variance revealed a significant genetic difference among date palms, while it showed a higher degree of within-cultivar genetic variability compared with that of among-population diversity. Some degree of common shared alleles occurred between date palm cultivars. Gst versus Nm analysis showed that some of the SCoT markers have a high discrimination power and may have a potential local adaptive value. The Mantel test showed a significant association (r =?0.40, P =?0.001) between morphological and genetic distances. Therefore, both morphological and SCoT molecular data can be used in genetic screening of date palms in the available germplasm.

     

台湾海峡晚更新世人类肱骨化石

产自台湾海峡海底的人类右肱骨石化程度高; 个体大而粗壮 ,三角肌粗隆发育 ,骨干上下两半段不在同一纵轴上 ,形成 6 5°的夹角 ,这些显示不同于新石器时代和现代人的原始性状 ,其演化水平和日本的港川人及欧洲的克罗马农人相当。与人化石一同捞出的哺乳动物化石有古菱齿象、野马、最后鬣狗、达氏四不像鹿等 ,表明其时代为晚更新世晚期。     

Production of coyol wine fromAcrocomia mexicana (Arecaceae) in Honduras

Production of “vino de coyol” (palm sap wine) fromAcrocomia mexicana (Arecaceae) was observed in Honduras. Trees are selected, felled, and tapped by cutting a small trough into one section of the crownshaft. The sap is collected, bottled, allowed to ferment for 24 h, and sold. The resulting beverage contains 12.86% alcohol but has little nutritional value. This is an example of a small-scale industry based on the harvest of wild palms     

Fine‐scale spatial differences in humpback whale diet composition near Kodiak,Alaska

On the North Pacific feeding grounds, humpback whales (Megaptera novaeangliae) are recovering from commercial whaling at a rapid rate (6.8%). The potential effect that this recovery will have on trophic dynamics involving these predators is currently unknown. To better elucidate complex trophic dynamics, variability in diet composition of apex predators on their respective feeding grounds needs to be understood. Thus, we explored the diet composition of two defined subaggregations of humpback whales of the Kodiak Archipelago population (“North,” “South”) using stable carbon (δ¹³C) and nitrogen (δ¹⁵N) isotope ratios of humpback whale skin and regional prey samples in Bayesian dietary mixing models. Humpback whales in the “North” region consumed proportionally more fish, dominated by capelin (Mallotus villosus), whereas, whales in the “South” region consumed predominantly krill. The difference in diet composition appears to reflect regional differences in prey availability. Thus, regional variability in diet composition by humpback whales may have disproportionate impacts on prey resources of sympatric predators depending on available prey biomass. As a result, we suggest fine‐scale studies of apex predator diets are needed to better model trophic dynamics with accuracy.     

Investigating the role of potassium and urea to control fruit drop and to improve fruit quality of “Dhakki” date palm

Fruit drop is a key issue with date palm cultivars that can be addressed with a variety of methods and strategies. Foliar application of macronutrients can be more effective in inhibiting fruit drop and improving the quality of date fruits. The current study was carried out to investigate the possible role of potassium (K) and urea to reduce fruit drop and improve the fruit quality of “Dhakki” date palm. It was conducted in a complete randomised block design with seven treatments and three replications at Pakistan's Agricultural Research Institute, Dera Ismail Khan. The treatments used were: (i) Control (distilled water spray); (ii) Potassium sulphate (K₂SO₄) at 1 %; (iii) K₂SO₄ at 1 % + Urea at 2 %; (iv) K₂SO₄ at 2 %; (v) K₂SO₄ at 2 % + Urea at 2 %; (vi) K₂SO₄ at 3 % and; (vii) K₂SO₄ at 3 % + Urea at 2 %. All the concentrations were sprayed at Kimri stage of fruit development during two consecutive growing seasons. Twenty-one date palms of equal size and age were chosen for the assessments to measure percent fruit drop and other physicochemical variables, including fruit length, fruit diameter, fruit weight, pulp percentage, yield/bundle, pH, total soluble solids (TSS), K content in fruit, and all sugars (percent) of harvested date fruit. The results revealed that bunch spray of K significantly affected all the parameters during both seasons. Application of K₂SO₄ alone and in combination with urea not only effectively reduced the fruit drop but also improved fruit quality in date where, K₂SO₄ applied at 2 % combined with urea was the best concentration in reducing fruit drop, enhancing other physicochemical attributes, and improving fruit quality of “Dhakki” date palm. This study may effectively contribute to reduce the fruit drop and enhance the fruit quality by using K and urea, enabling farmers to improve the date yield and increase economic growth.     

The function of three main call types in common cuckoo

Acoustic signals play a key role in shaping the relationships in birds. Common cuckoos Cuculus canorus are known to produce various call types, but the function of these calls has only been studied recently. Here, we used a combination of field recordings (conducted in 2017) and playback experiments (conducted in 2018) to investigate the functional significance of common cuckoo calls. We found significant differences in the characteristics between male two‐element “cu‐coo” and three‐element “cu‐cu‐coo” calls, with these two call types being used in different contexts. The three‐element male “cu‐cu‐coo” calls were associated with females emitting their “bubbling” call. Playback experiments revealed that both males and females exhibit stronger responses to playing female “bubbling” calls than with the calls of the Eurasian sparrowhawk (Accipter nisus) serving as a control, suggesting a significant intraspecific communication function for this call type. However, we did not find any evidence to support mate attraction in male calls, as females were not stimulated by playback of male calls compared with sparrowhawk calls in the control group.     

Structural and taphonomic analysis of a columnar coralline algal build-up from SE Sicily

Unusual “coralligenous” build-ups were found at the infra–circalittoral boundary from SE Sicily. They are columnar, rising up perpendicularly from the bottom, and consist of an inter-growth of encrusting algae and invertebrates. A selected build-up and its longitudinal section, together with some thin sections of selected parts, were studied to detail the growth structures, composition and fabric of the trapped sediments. The coralline algae show a succession of “concentric”, “fruticulose” and “foliaceous” structures. The framework delineates cavities bounded by algal thalli, sometimes filled by sediments. The organisms constituting the framework were grouped into functional guilds (Fagerström, 1991): “primary frame builders” (mainly coralline algae); “secondary frame builders” (vermetids, serpulids and some bryozoans); “bafflers” (erect, flexible bryozoans, some sponges and soft algae); “binders” (encrusting bryozoans, some crustose coralline algae and serpulids); “destroyers” (a few endolithic algae, rare sponges and bivalves); “dwellers” (brachiopods, foraminifers, bivalves, small bryozoans and some motile organisms). The distribution pattern of taphonomic features (composition, grain size and distribution of sediments filling cavities; presence of cement and its location; mineralogical composition and crystal size), together with interactions between growth structures and functional guilds, allowed one to distinguish three taphofacies, each recording different environmental conditions. They have been tentatively related with cyclic sequences testifying to local hydrodynamic regimes, with subsequent slighter and stronger intensity phases, during the last 2200 years.     

Body composition determinants of metabolic phenotypes of obesity in nonobese and obese postmenopausal women

Objective : Although obesity is typically associated with increased cardiovascular risk, a subset of obese individuals display a normal metabolic profile (“metabolically healthy obese,” MHO) and conversely, a subset of nonobese subjects present with obesity‐associated cardiometabolic abnormalities (“metabolically obese nonobese,” MONO). The aim of this cross‐sectional study was to identify the most important body composition determinants of metabolic phenotypes of obesity in nonobese and obese healthy postmenopausal women. Design and Methods : We studied a total of 150 postmenopausal women (age 54 ± 7 years, mean ± 1 SD). Based on a cardiometabolic risk score, nonobese (body mass index [BMI] ≤ 27) and obese women (BMI > 27) were classified into “metabolically healthy” and “unhealthy” phenotypes. Total and regional body composition was assessed with dual‐energy X‐ray absorptiometry (DXA). Results : In both obese and nonobese groups, the “unhealthy” phenotypes were characterized by frequent bodyweight fluctuations, higher biochemical markers of insulin resistance, hepatic steatosis and inflammation, and higher anthropometric and DXA‐derived indices of central adiposity, compared with “healthy” phenotypes. Indices of total adiposity, peripheral fat distribution and lean body mass were not significantly different between “healthy” and “unhealthy” phenotypes. Despite having increased fat mass, MHO women exhibited comparable cardiometabolic parameters with healthy nonobese, and better glucose and lipid levels than MONO. Two DXA‐derived indices, trunk‐to‐legs and abdominal‐to‐gluteofemoral fat ratio were the major independent determinants of the “unhealthy” phenotypes in our cohort. Conclusions : The “metabolically obese phenotype” is associated with bodyweight variability, multiple cardiometabolic abnormalities and an excess of central relative to peripheral fat in postmenopausal women. DXA‐derived centrality ratios can discriminate effectively between metabolic subtypes of obesity in menopause.