The polysaccharides of mango seeds (mangifera indica,var. bullock's heart)

Mangoes (Mangifera indica) are grown in many warm regions of the world; for example, in Australia, Brazil, India, South America, and the United States (California and Florida), and along the shores of the Mediterranean sea (Egypt, Italy, and Spain). In Egypt, many varieties yielding delicious fruits are grown in large quantities (50,000 tons annually). Mango kernels are used for feeding mammals and chickens. Starch has been isolated from mango and its physical properties studied.The aim of the present work was to study the polysaccharides present in mango kernels.     

Karenia brevis monitoring,management, and mitigation for Florida molluscan shellfish harvesting areas

The purpose of this paper is to describe the State of Florida Karenia brevis monitoring, management and mitigation procedures for the harvesting of safe molluscan shellfish. Monitoring and management to prevent public health impacts of due to brevetoxins from K. brevis in shellfish has worked successfully for over forty years. Over the past forty years there have been no reports of human illness resulting from the consumption of commercial or recreational harvest harvested of shellfish from Florida waters that were classified as open. Therefore, this monitoring and management program has been a highly successful public health program. In addition, opportunities exist for mitigation which may allow for limited shellfish harvesting and safe consumption during blooms. The key elements of the Florida program are provided as a “model” or “ideal” monitoring, management, and mitigation program.     

Occurrence of moniliformin,deoxynivalenol, and zearalenone in durum wheat (Triticum durum Desf.)

Forty-eight durum wheat samples from 5 locations in Austria were examined forFusarium infection andFusarium toxin content.F.gramlnearum andF.avenaceum were by far the prevailingFusarium species In durum wheat kernels, followed byEpoae, F.culmorum, andF.equlsetl. Ion-paired HPLC analyses of the samples showed moniliformin contents of kernels up to 0.88 mg/kg. All moniliformin contaminated samples also contained high levels of deoxynivalenol (up to 8.2 mg/kg) and lower levels of zearalenone (<0.33 mg/kg). The levels of zearalenone in naturally contaminated durum wheat samples did not correspond to the high yields of zearalenone found in cultures of the fusaria isolated from the durum wheat kernels. These conflicting results as well as some toxicologlcal aspects of the carry over ofFusarium toxins from durum wheat kernels into pasta are discussed.     

Characterization of a New Burrowing Nematode Population,Radopholus citrophilus,from Hawaii

Karyotype, host preference, isozyzme patterns, morphometrics, and mating behavior of two burrowing nematode populations from Hawaii, one infecting Anthurium sp. and the second infecting Musa sp., were compared with Radopholus similis and R. citrophilus populations from Florida. The population from Anthurium sp. had five chromosomes (n = 5), and that from Musa sp. had four (n = 4). Neither of the Hawaiian nematode populations persisted in roots of Citrus limon or C. aurantium. Anthurium clarinerivum and A. hookeri were hosts of the burrowing nematode population from anthurium in Hawaii and of R. citrophilus from Florida, whereas the two anthurium species were poor hosts of the population from Musa sp. in Hawaii and R. similis from Florida. The isozyme pattern of the population isolated from anthurium was identical to that of R. citrophigus, whereas the pattern of the population from banana in Hawaii was identical to that of R. similis. Mating behavior between the burrowing nematode population isolated from Anthurium sp. and a Florida population of R. citrophilus supports their close taxonomic relationship. Mating was observed between the population from Anthurium sp. and the Florida population of R. citrophilus but not between the Hawaiian burrowing nematode population isolated from Musa sp. and a Florida population of R. citrophilus. These findings indicate that a previously unidentified population of R. citrophilus which does not parasitize citrus occurs in Hawaii.     

Susceptibility of Several Common Subtropical Weeds to Meloidogyne arenaria,M. incognita,and M. javanica

Experiments were conducted in the greenhouse to assess root galling and egg production of three root-knot nematode species, Meloidogyne arenaria, M. incognita, and M. javanica, on several weeds common to Florida agricultural land. Weeds evaluated were Amaranthus retroflexus (redroot pigweed), Cyperus esculentus (yellow nutsedge), Eleusine indica (goosegrass), Portulaca oleracea (common purslane), and Solanum americanum (American black nightshade). Additionally, although it is recommended as a cover crop in southern regions of the U.S., Aeschynomene americana (American jointvetch) was evaluated as a weed following the detection of root galling in a heavy volunteer infestation of an experimental field in southeastern Florida. Weeds were propagated from seed and inoculated with 1000 nematode eggs when plants reached the two true-leaf stage. Tomato (Solanum lycopersicum ‘Rutgers’) was included as a positive control. Aeschynomene americana and P. oleracea roots supported the highest number of juveniles (J₂) and had the highest number of eggs/g of root for all three species of Meloidogyne tested. However, though P. oleracea supported very high root levels of the three nematode species tested, its fleshy roots did not exhibit severe gall symptoms. Low levels of apparent galling, combined with high egg production, increase the potential for P. oleracea to support populations of these three species of root-knot nematodes to a degree that may not be appropriately recognized. This research quantifies the impact of P. oleracea as a host for M. arenaria, M. incognita, and M. javanica compared to several other important weeds commonly found in Florida agricultural production, and the potential for A. americana to serve as an important weed host of the three species of root-knot nematode tested in southern regions of Florida.     

Susceptibility of the cabbage looper, Trichoplusia ni, and the velvetbean caterpillar, Anticarsia gemmatalis, to several isolates of the entomopathogenic fungus Nomuraea rileyi

Cabbage looper larvae, Trichoplusia ni, were equally susceptible to isolates of the entomogenous fungus Nomuraea rileyi from Missouri, Mississippi, and Brazil; an isolate from Florida was 7–17 times less active than the other isolates. Velvetbean caterpillars, Anticarsia gemmatalis, were either only slightly susceptible or not susceptible to the isolates of N. rileyi from Missouri, Florida, and Mississippi. In contrast, larvae of A. gemmatalis cultured from three locations (Missouri, Florida, and Brazil) all were equally susceptible to a Brazilian isolate of N. rileyi.     

Biology, distribution and host-range of the sawfly,Lophyrotoma zonalis (Hym. pergidae), a potential biological control agent for the paperbark tree,Melaleuca quinquenervia

Since its introduction into southern Florida at the beginning of this century, the Australian paperbark tree,Melaleuca quinquenervia (Cav.) S. T. Blake, has become a major economic and environmental pest. A project to develop biological control agents for this tree in Australia began in 1986. Among a number of potential agents, a defoliating sawfly,Lophyrotoma zonalis (Rohwer) (Hymenoptera: Pergidae), was selected for further study. The larvae of this sawfly are conspicuous defoliators ofMelaleuca trees in northern Queensland. We collected these sawflies from Cairns to Mackay in northern Queensland, and they are also known from the Northern Territory and New Guinea. The life-cycle from egg to adult takes about 12 weeks. The egg, larval and pupal stages are parasitized by dipteran and hymenopteran parasites. We conducted 2234 larval no-choice feeding tests on 46 plant species from 20 families. Although feeding occurred on 35 of these plant species,M. quinquenervia and its close relative,M. leucadendra (L.) L., were preferred. In oviposition tests, larvae only emerged from egg cases laid onM. quinquenervia andM. leucadendra. Our extensive field surveys of nearly 70 tree species foundL. zonalis eggs and larvae only on several closely relatedMelaleuca species. The potential effectiveness of this sawfly as a biocontrol agent is discussed and estimated using the Goeden-Harris scoring system. Quarantine studies of this insect began in Florida in early 1994.     

Genetic variation in the green anole lizard (Anolis carolinensis) reveals island refugia and a fragmented Florida during the quaternary

The green anole lizard (Anolis carolinensis) is a model organism for behavior and genomics that is native to the southeastern United States. It is currently thought that the ancestors of modern green anoles dispersed to peninsular Florida from Cuba. However, the climatic changes and geological features responsible for the early diversification of A. carolinensis in North America have remained largely unexplored. This is because previous studies (1) differ in their estimates of the divergence times of populations, (2) are based on a single genetic locus or (3) did not test specific hypotheses regarding the geologic and topographic history of Florida. Here we provide a multi-locus study of green anole genetic diversity and find that the Florida peninsula contains a larger number of genetically distinct populations that are more diverse than those on the continental mainland. As a test of the island refugia hypothesis in Pleistocene Florida, we use a coalescent approach to estimate the divergence times of modern green anole lineages. We find that all demographic events occurred during or after the Upper Pliocene and suggest that green anole diversification was driven by population divergence on interglacial island refugia in Florida during the Lower Pleistocene, while the region was often separated from continental North America. When Florida reconnected to the mainland, two separate dispersal events led to the expansion of green anole populations across the Atlantic Seaboard and Gulf Coastal Plain.     

Abscisic Acid inhibition of endosperm cell division in cultured maize kernels

The response of developing maize (Zea mays L.) endosperm to elevated levels of abscisic acid (ABA) was investigated. Maize kernels and subtending cob sections were excised at 5 days after pollination (DAP) and placed in culture with or without 90 micromolar (±)-ABA in the medium. A decreased number of cells per endosperm was observed at 10 DAP (and later sampling times) in kernels cultured in medium containing ABA from 5 DAP, and in kernels transferred at 8 DAP to medium containing ABA, but not in kernels transferred at 11 DAP to medium containing ABA. The number of starch granules per endosperm was decreased in some treatments, but the reduction, when apparent, was comparable to the decreased number of endosperm cells. The effect on endosperm fresh weight was slight, transient, and appeared to be secondary to the effect on cell number. Mature endosperm dry weight was reduced when kernels were cultured continuously in medium containing ABA. Endosperm (+)-ABA content of kernels cultured in 0, 3, 10, 30, 100, or 300 micromolar (±)-ABA was measured at 10 DAP by indirect ELISA using a monoclonal antibody. Content of (+)-ABA in endosperms correlated negatively (R = −0.92) with endosperm cell number. On the basis of these studies we propose that during early kernel development, elevated levels of ABA decrease the rate of cell division in maize endosperm which, in turn, could limit the storage capacity of the kernel.     

Peanut Pod Invasion by Aspergillus flavus in the Presence of Meloidogyne hapla

''Argentine'', ''Early Runner'' and ''Florigiant'' peanut cultivars were grown in methyl bromide treated soil in field microplots inoculated with: (i) Aspergillus flavus or (ii) A. flavus + Meloidogyne hapla. Nematode infection produced heavy root galling and light pod galling equally on all cultivars. A. flavus, A. niger, Cephalosporium spp., Colletotrichum sp., Curvularia spp., Fusarium spp., Penicillium spp. and Trichoderma viride were isolated from shells and kernels. A significantly greater incidence and density of A. flavus was obtained from kernels of plants inoculated with both organisms than from kernels of plants receiving only the fungus. Differences were not significant, however, for incidence and density of A. flavus in shells or for the total of all fungal propagules in shells and kernels. Shells of ''Early Runner'' contained significantly greater incidence and density of A. flavus than the other two cultivars; also, kernels of this cultivar contained more fungal propagules than kernels of ''Argentine.'' A significantly larger number of total fungi was isolated from kernels of ''Argentine'' than from ''Florigiant.'' Aflatoxins were found only in two shell samples and not in kernels.     

A Quantitative Estimation of Alkali-labile Indole-3-Acetic Acid Compounds in Dormant and Germinating Maize Kernels

An estimate has been made of the quantities of alkali-labile esters of indoleacetic acid (IAA) in kernels of sweet corn (Zea mays). The amount is between 70 to 90 mg of IAA per kilogram of dry kernels. About one-half of the IAA is present as high molecular weight esters and the remaining one-half as esters of myo-inositol. Free IAA, which may have existed in the kernels, or may have resulted from ester hydrolysis during isolation or storage, amounts to between 1 to 10% of the esterified IAA. Five newly observed low molecular weight indoleacetyl compounds are described and their chromatographic behavior reported. The total IAA content of corn kernels and intact seedlings decreases during germination, declining to about 10% of the original content during 96 hr of germination. Difficulties in obtaining quantitative results and the possible physiological significance of these results is discussed.     

Predicting Salmonella Populations from Biological,Chemical, and Physical Indicators in Florida Surface Waters

Coliforms, Escherichia coli, and various physicochemical water characteristics have been suggested as indicators of microbial water quality or index organisms for pathogen populations. The relationship between the presence and/or concentration of Salmonella and biological, physical, or chemical indicators in Central Florida surface water samples over 12 consecutive months was explored. Samples were taken monthly for 12 months from 18 locations throughout Central Florida (n = 202). Air and water temperature, pH, oxidation-reduction potential (ORP), turbidity, and conductivity were measured. Weather data were obtained from nearby weather stations. Aerobic plate counts and most probable numbers (MPN) for Salmonella, E. coli, and coliforms were performed. Weak linear relationships existed between biological indicators (E. coli/coliforms) and Salmonella levels (R² < 0.1) and between physicochemical indicators and Salmonella levels (R² < 0.1). The average rainfall (previous day, week, and month) before sampling did not correlate well with bacterial levels. Logistic regression analysis showed that E. coli concentration can predict the probability of enumerating selected Salmonella levels. The lack of good correlations between biological indicators and Salmonella levels and between physicochemical indicators and Salmonella levels shows that the relationship between pathogens and indicators is complex. However, Escherichia coli provides a reasonable way to predict Salmonella levels in Central Florida surface water through logistic regression.     

RNA Viral Metagenome of Whiteflies Leads to the Discovery and Characterization of a Whitefly-Transmitted Carlavirus in North America

Whiteflies from the Bemisia tabaci species complex have the ability to transmit a large number of plant viruses and are some of the most detrimental pests in agriculture. Although whiteflies are known to transmit both DNA and RNA viruses, most of the diversity has been recorded for the former, specifically for the Begomovirus genus. This study investigated the total diversity of DNA and RNA viruses found in whiteflies collected from a single site in Florida to evaluate if there are additional, previously undetected viral types within the B. tabaci vector. Metagenomic analysis of viral DNA extracted from the whiteflies only resulted in the detection of begomoviruses. In contrast, whiteflies contained sequences similar to RNA viruses from divergent groups, with a diversity that extends beyond currently described viruses. The metagenomic analysis of whiteflies also led to the first report of a whitefly-transmitted RNA virus similar to Cowpea mild mottle virus (CpMMV Florida) (genus Carlavirus) in North America. Further investigation resulted in the detection of CpMMV Florida in native and cultivated plants growing near the original field site of whitefly collection and determination of its experimental host range. Analysis of complete CpMMV Florida genomes recovered from whiteflies and plants suggests that the current classification criteria for carlaviruses need to be reevaluated. Overall, metagenomic analysis supports that DNA plant viruses carried by B. tabaci are dominated by begomoviruses, whereas significantly less is known about RNA viruses present in this damaging insect vector.     

A brief summary of the physiology and ecology of Karenia brevis Davis (G. Hansen and Moestrup comb. nov.) red tides on the West Florida Shelf and of hypotheses posed for their initiation,growth, maintenance,and termination

This contribution represents a review of the historical and recent literature describing the environmental factors that relate to the distribution, growth, primary production, nutrient requirements and utilization along with hypotheses that are extant for the initiation, growth, maintenance and termination of Karenia brevis blooms on the West Florida Shelf. Potential nutrient sources that support blooms and relate to recent questions on the duration, frequency, and intensity of WFS blooms are summarized and some thoughts are presented which relate to the question of why K. brevis, a slow growing dinoflagellate, becomes dominant in a nearshore shelf region that is typically dominated by diatoms.There is no single hypothesis that can account for blooms of K. brevis along the west coast of Florida. Of the approximately 24 thoughts and hypotheses described herein (including the 1880s speculation), seven are related to rainfall and/or riverine flux, six invoke the benthos or bottom flux in one form or another, seven involve water column hydrodynamics or are unrelated to the benthos or land sources, and four are primarily chemical/allelopathy based. Nutrient sources for growth and maintenance range from atmospheric deposition, N-fixation, riverine and benthic flux, and zooplankton excretion to decaying fish killed by the toxic dinoflagellate with no one source being conclusively identified as a primary contributor to prolonged bloom maintenance. Insufficient information is available to delimit specific mechanisms that may play a role in the termination of K. brevis blooms. However, general processes such as macro- and microzooplankton grazing, bacterial and viral cell lysis, and dispersal by physical advection and the break down of fronts, that originally may have acted as concentrating mechanisms, are reviewed.     

Cytokinin oxidase fromZea mays kernels andVinca rosea crown-gall tissue

Cytokinin oxidase has been partially purified from matureZea mays kernels and fromVinca rosea corwn-gall tissue. The molecular weights of the two enzymes, determined by gel filtration, are very different: 94,400 (±10%) forZ. mays and 25,100 (±10%) forV. rosea. Specificity studies have been performed using a large number of synthetic and naturally occurring cytokinins. Only a small number of these compounds serve as substrates and both enzymes exhibit similar substrate specificity. In agreement with other workers, a Δ² double bond in the N⁶ side chain is essential for activity. The presence of glucosyl or ribosyl groups in the 7-or 9-position or an alanyl group in the 9-position of the purine moiety have little effect on their susceptibility to cytokinin oxidase, but O-glucosyl derivatives are resistant to oxidation. The relevance of these enzyme systems to studies on cytokinin metabolism and to the endogenous cytokinins is discussed.     

Karenia brevis red tides,brevetoxins in the food web,and impacts on natural resources: Decadal advancements

As recently as a decade ago, Karenia brevis red tides and their effects on animal resources in the Gulf of Mexico were principally perceived as acute blooms that caused massive fish kills. Although occasional mortalities of higher vertebrates were documented, it has only been in the past decade that conclusive evidence has unequivocally demonstrated that red tides and their brevetoxins are lethal to these organisms. Brevetoxins can be transferred through the food chain and are accumulated in or transferred by biota at many trophic levels. The trophic transfer of brevetoxins in the food web is a complex phenomenon, one that is far more complicated than originally conceived. Unexplained fish kills and other animal mortalities in areas where red tide is endemic are being increasingly linked with post-bloom exposures of biota to brevetoxins. Mass mortality events of endangered Florida manatees (Trichechus manatus latirostris) follow a consistent spatial and temporal pattern, occurring primarily in the spring in southwestern Florida. Persistent blooms can also cause a cascade of environmental changes, affecting the ecosystem and causing widespread die-offs of benthic communities. Ongoing fish kills from sustained blooms can lead to short-term declines in local populations. Although animal populations in areas where red tide is endemic are unquestionably at risk, it remains to be determined to what extent populations can continue to recover from these sustained effects.     

Bathyal ostracodes from the Florida-Hatteras slope,the Straits of Florida,and the Blake Plateau

Epibathyal ostracodes from the Florida-Hatteras slope, the Blake Plateau and the Straits of Florida were studied to determine the relationship of numerous genera and species to bottom-water environmental conditions such as dissolved oxygen and bottom-water temperatures. From a total of 100 samples, 44 samples evenly distributed between 200 and 1100 m water depth and having an average of 325 specimens were examined in detail.Using occurrence data from the adjacent continental shelf, carapace preservation, Rose Bengal staining and population data, indigenous death assemblages were distinguished from transported or reworked fossil specimens. The percent of transported specimens varied as follows: Blake Plateau < 1%; Straits of Florida 10–60%; Florida-Hatteras slope 1–15%. Indigenous death assemblages contained between 10 and 61 species per sample, averaging 33.3 species.Krithe, Argilloecia andPseudocythere occur in > 90% of the samples and usually constitute 10 to 30% of each.Trachyleberidea, Bairdoppilata, Saida, Paranesidea, Ambocythere, Bythocypris, Cytherella, Bradleya, Henryhowella, and Polycopidae occur in 45 to 80% of the samples in varying percentages.The upper depth limits of 39 taxa occur at or just below the thermocline suggesting a relationship to temperature.Australoecia, Quasibuntonia, Cytheropteron, Ruggieriella, Saida, Ambocythere, Trachyleberidea, Macrocypris, Krithe, “Thalassocythere”, andCytherella are most common or restricted to the O₂ minimum zone. Conversely,Anchistrocheles, Bradleya, Henryhowella, andRockallia are most common below 750 m in well oxygenated water with temperatures below 8°C.The results show that: (1) ostracodes display a narrow depth zonation controlled by dissolved oxygen and water temperature; (2) species diversity is very high for a bathyal zone; (3) ostracodes can be used to identify the source of sediment that has been transported downslope; and (4) some taxa are useful in recognizing low oxygenated water in Cenozoic deposits.     

The Occurrence and Development of Amylase Enzymes in Incubated, De-embryonated Maize Kernels

The development of amylase activity in extracts from de-embryonated and GA₃-treated de-embryonated maize kernels (Zea mays L.) was determined during a 10-day incubation period. The increase in activity was compared with activity extracted from endosperms dissected from germinating whole kernels. Chromatographic analysis of reaction products as well as physicochemical characterization demonstrated that the activities from GA₃-treated and nontreated tissue were comparable and that part of the activity was attributable to α-amylase.