Could the Supply of Boron and Zinc Improve Resistance of Potato to Early Blight?     

Patrícia Pereira Machado  Fábio Steiner  Alan Mario Zuffo  Rafael Alves Machado 《Potato Research》2018,61(2):169-182

The adequate supply of boron (B) and zinc (Zn) can improve the structural integrity and permeability of cell membranes, which is a defence mechanism against fungi infection. A greenhouse experiment was conducted to investigate the effect of the application of B and Zn on plant growth and the incidence and severity of potato early blight, a destructive foliar disease of potato crop caused by Alternaria grandis E.G. Simmons. Potato plants (Solanum tuberosum L. cv. Ágata) were grown in 11-l pots filled with sandy soil, unfertilized or fertilized with 5 mg kg^?1 B and 5 mg kg^?1 Zn (either alone or in combination). Potato plants were inoculated with isolates of Alternaria grandis at 40 days after planting. Early blight incidence and severity were evaluated visually 7 days after inoculation with A. grandis isolates. Disease incidence ranged from 16 to 41% infected leaves, and was significantly highest in the treatment with the application of B, followed by the control, and lowest with application of Zn and B + Zn. Early blight severity ranged from 2.5 to 25%, and was significantly higher in the unfertilized treatment than in those fertilized with Zn either alone or in combination with B. These findings suggest that Zn plays a critical role in potato tolerance to early blight and should be considered as a preventive measure in the disease management plan, since application of zinc reduced the incidence and severity of potato early blight. However, the physiological basis of this remains unknown.  相似文献   

Potential external contamination of pneumatic seed drills during sowing of dressed maize seeds          下载免费PDF全文

Marco Manzone  Paolo Balsari  Paolo Marucco  Mario Tamagnone 《Pest management science》2016,72(7):1302-1308

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Interacting effects of soil degradation and precipitation on plant productivity in NE Patagonia,Argentina     

María Victoria Campanella  César Mario Rostagno  Lina Sonia Videla  Alejandro Jorge Bisigato 《Arid Land Research and Management》2016,30(1):79-88

Our objective was to examine the effects of inter-annual variation of precipitation on productivity of two dominant species (Chuquiraga avellanedae, an evergreen shrub, and Nassella tenuis, a perennial grass) in two communities of contrasting soil degradation: a herbaceous steppe with shrubs (HSS) and a degraded shrub steppe (SS). Data were collected during two consecutive years with different annual precipitation. Aboveground productivity was determined nondestructively using a double sampling approach. The number of inflorescences per plant was recorded too. Perennial grass productivity was lower in SS than in HSS in both years, while shrub productivity was lower in SS only during the year of below average precipitation. With rising precipitation the perennial grass increased the number of inflorescences while the evergreen shrub augmented vegetative biomass. In summary, the effects of precipitation on plant productivity are community dependent; abiotic factors, such as superficial and sub-superficial soil characteristics, and biotic factors, such as leaf area index (LAI) or tussock sizes, may interact to influence the responses of species to precipitation. Our results suggest that if precipitation increased, this would favor the dominance of shrubs over grasses.  相似文献   

Agronomical,quality, and molecular characterization of twenty Italian emmer wheat (<Emphasis Type="Italic">Triticum dicoccon</Emphasis>) accessions     

Mario Augusto Pagnotta  Linda Mondini  Pasquale Codianni  Clara Fares 《Genetic Resources and Crop Evolution》2009,56(3):299-310

Emmer wheat (Triticum dicoccon Schrank, 2n = 4x = 28) consists in a hulled wheat; its cultivation has been drastically reduced during the last century as a consequence of its low yield. Recently, its agronomic and nutritive values, as well as the increase of popularity of organic agriculture, have led to a renewed interest making its cultivation economically viable in the marginal lands with an increase of the cultivated areas. In Italy, it mainly survives in few marginal lands of central and southern Italy, where local varieties, adapted to the natural environment from where they originate, are used; moreover, some selected lines have also been developed. In the present work, agro-morphological and qualitative traits, together with molecular analyses of 20 emmer accessions consisting of Italian landraces, breeding lines, and cultivars, were performed. The field experiments were conducted for two consecutive years (2001/2002–2002/2003) in two locations: Viterbo in central Italy, and Foggia in south Italy. The analyzed emmer wheat accessions showed a good amount of genetic variability for both evaluated agro-morphological and molecular traits. This study illustrates an increase in earliness, GY, TW, TKW, and YI going from landraces, breeding lines to cultivars, while the variability does not change proportionally.  相似文献   

Mycorrhizal Hyphal Length as a Function of Plant Community Richness and Composition in Restored Northern Tallgrass Prairies (USA)     

Marcus A. Bingham  Mario Biondini 《Strength and Conditioning Journal》2009,62(1):60-67

We assessed the total length of external arbuscular mycorrhizal hyphae as a function of plant species and functional form richness in restored northern tallgrass prairies. Total hyphal length increased with species and functional form richness. Hyphal length also increased when plant communities were dominated by species with high root density, high root to shoot ratios, and high nitrogen use efficiency. Hyphal length was positively correlated with the biomass of late successional C₄ grasses (Andropogon gerardi Vitman, Panicum virgatum L., Schizachyrium scoparium [Michx.] Nash-Gould, and Sorghastrum nutans L.), which are obligately mycorrhizal and characterized by high root to shoot ratios, and high root surface area per unit of root biomass. We thus conclude that in order to recover extraradical arbuscular mycorrhizal hyphal length in restored northern tallgrass prairies, at least three factors need to be given priority: 1) achieving high levels of species and functional form richness; 2) making sure that late successional C₄ grasses are present; and 3) making sure that the seed mixture includes species that are characterized by high root to shoot ratio, high root density, and high nitrogen-use efficiency.  相似文献   

Heifer teats sprayed in the dry period with an iodine teat sanitizer have reduced Streptococcus uberis teat-end contamination and less Streptococcus uberis intra-mammary infections at calving     

Lopez-Benavides MG  Williamson JH  Lacy-Hulbert SJ  Cursons RT 《Veterinary microbiology》2009,134(1-2):186-191

Heifers managed under pastoral conditions are at risk from Streptococcus uberis mastitis infections at calving. A total of 397 heifers from six farms around New Zealand were enrolled in a study to identify and enumerate S. uberis on teat-ends of heifers in the peri-partum period, and to understand the effect of teat-spraying in the pre-calving period on the prevalence and incidence of S. uberis mastitis post-calving. Heifers were randomly assigned to Control or Sprayed groups. Sprayed heifers were teat-sprayed once, three times a week (Monday, Wednesday and Friday) with a commercial iodine-based teat sanitizer, starting at 3 weeks prior to calving and ending at day of calving. Across three farms, all glands of cows in both groups were sampled at calving to determine S. uberis intra-mammary infection (IMI) prevalence. For all farms, clinical mastitis (CM) cases detected during the week after calving were sampled and submitted for bacteriological analysis. Swabbing of teat-ends of 54 heifers from one farm showed that heifers had a pre-existing S. uberis contamination averaging 610 colony-forming units per swab (cfu/swab), at 3 weeks prior to calving. At calving, teat-end contamination was 560 cfu/swab for Sprayed heifers and 1775 cfu/swab for Control heifers. Two weeks after calving, teat-end contamination was similar between both groups, at 30 cfu/swab. The prevalence of S. uberis IMI was significantly lower in the Sprayed (3.5% glands) vs. the Control (7.4%) heifers in the first week after calving. There was a trend for Sprayed heifers (3.6% heifers) to have a lower incidence of S. uberis CM compared with Control heifers (7.4% heifers). It is concluded that teat-spraying in the dry period is a management option that could contribute to controlling heifer S. uberis mastitis in the transition period.  相似文献   

Net requirements of calcium, magnesium, sodium, phosphorus, and potassium for growth of Nellore × Red Angus bulls, steers, and heifers   总被引：1，自引：0，他引：1  

Mario Luiz Chizzotti  Sebastio de Campos Valadares Filho  Luis Orlindo Tedeschi  Pedro Veiga Rodrigues Paulino  Mrio Fonseca Paulino  Rilene Ferreira Diniz Valadares  Paloma Amaral  Pedro Del Bianco Benedeti  Tainnah Ikegami Rodrigues  Mozart Alves Fonseca 《Livestock Science》2009,124(1-3):242-247

A comparative slaughter trial was conducted to assess the net requirements for gain of Ca, P, Na, K and Mg of bulls, steers and heifers of Nellore and Red Angus crossbreds. Twenty seven F1 Nellore and Red Angus crossbred calves (9 steers, 9 bulls, and 9 heifers), averaging 274 kg BW, were used. At the beginning of the trial, three animals from each gender were slaughtered to determine the initial body composition. The remaining 18 animals (3 animals of each gender) were randomly assigned to two treatments: fed 0.75 or 1.5% of BW of concentrate. The diets were based on corn silage and were isonitrogenous (2% N, DM). After three growing periods of 28 d, all animals were slaughtered. The cleaned gastrointestinal tract, organs, carcass, head, hide, tail, feet, and tissues were weighed to determine the empty BW (EBW). These parts were ground separately and subsampled for chemical analyses. The log of the contents of each mineral in the empty body was regressed on the log of the EBW to estimate the net requirement for each mineral per kg of empty body gain (EBG). There were no differences (P > 0.05) in the net requirements for growth of all macrominerals among genders. The equations of the pooled data of the net requirements for growth (g/kg EBG) were: 332.6 × EBW ^− 0.6367 for Ca, 112.1 × EBW ^− 0.5615 for P, 10.85 × EBW ^− 0.3992 for Na, 4.01 × EBW ^− 0.153 for K, and 3.589 × EBW ^− 0.462 for Mg. Our findings indicated that retained Ca and retained P were poorly related to the retained protein.  相似文献   

Population structure of the European conger Conger conger from the mid-North Atlantic Ocean inferred from bathymetric distribution,length composition and movement patterns analyses     

Wendell Medeiros-Leal  Régis Santos  Ana Novoa-Pabon  Hélder Silva  Mario Pinho 《Fisheries Management and Ecology》2021,28(5):468-477

Information about the population structure of Conger conger (L.) is scarce, being a limiting factor for fisheries assessment. To make available important baseline information and to test the hypothesis that the population in the mid-North Atlantic (Azores region) represents a fishery management unit, fishery-dependent and survey data relating to bathymetric distribution, length composition and movement patterns were examined. Fishing impacts were also evaluated using abundance and size trends over the last 25 years. The greatest abundance was in depths between 300 and 600 m. Sizes ranged from 14 to 260 cm, with larger individuals around seamounts. Tagging data showed a strong sedentary behaviour. Results combined with previous genetic and otolith studies indicated the stock in the Azores may represent a self-contained population. Abundance and size trends were stable, but the species is considered vulnerable to overfishing due to its biological characteristics. Monitoring and adequate rational resource management are of utmost importance.  相似文献   

Establishment limitation of holm oak (Quercus ilex subsp. ballota (Desf.) Samp.) in a Mediterranean savanna — forest ecosystem     

Christian Smit  Mario Díaz  Patrick Jansen 《Annals of Forest Science》2009,66(5):511-511

? Tree recruitment in Mediterranean savannas is generally hampered, in contrast with the original oak forests where these savannas are derived from. We asked whether this difference in recruitment success can be explained by differential post-dispersal survival. For one year we monitored experimentally cached holm oak acorns in a savanna — forest ecosystem in Central Spain, and recorded cache pilferage, type of pilferer, boar rooting, seedling emergence, seedling survival and the cause of mortality.

? Cache pilferage was significantly lower in savanna (8%) than in forest (21%). However, the higher cache survival was more than offset by lower seedling emergence and, particularly, by nine times higher seedling mortality in savanna, mainly due to desiccation. Wild boar rooting did not differ between experimental caches and controls without acorns, indicating that individual cached acorns do not trigger rooting activity.

? Our results indicate that the difference in post-dispersal survival between savanna and forest is due to lower emergence and, primarily, higher seedling mortality in savanna, not to higher cache pilferage. Absence of safe sites such as shrubs, abundantly present in the forest, may well explain the lack of recruitment in the savanna. Management measures appear necessary for long-term persistence of Mediterranean savannas in general.

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Dissection of antioxidant activity of durum wheat (Triticum durum Desf.) grains as evaluated by the new LOX/RNO method     

Maura Nicoletta Laus  Damiana Tozzi  Mario Soccio  Alessandra Fratianni  Gianfranco Panfili  Donato Pastore 《Journal of Cereal Science》2012

Antioxidant activity (AA) of durum wheat (Triticum durum Desf.) grains was studied using the innovative LOX/RNO method, able to simultaneously detect different antioxidant mechanisms, and the TEAC assay, one of the most widely used assays. Insoluble-bound and free-soluble phenols, hydrophilic and lipophilic compounds were extracted from eight different whole flour samples; extracts were analyzed for AA and their content in several antioxidants. The LOX/RNO method measured very high AA values, with the highest ones [850–1500 μmol Trolox eq./g whole flour (dry weight)] for insoluble-bound phenolic extracts, highly correlated to total phenolic (r = 0.761, P < 0.001) and ferulic acid (r = 0.816, P < 0.001) contents. Hydrophilic and lipophilic extracts showed lower AA [70-140 and 40–60 μmol Trolox eq./g (dry weight), respectively], highly correlated to flavonoid (r = 0.583, P < 0.01) and protein (r = 0.602, P < 0.01), as well as β-tocotrienol (r = 0.684, P < 0.05) contents, respectively. Interestingly, the LOX/RNO method suggests that insoluble-bound phenolic compounds may exert very strong synergistic interactions within the extract. Contrarily, the TEAC assay did not correlate to any antioxidant content, resulted unable to highlight differences among samples, measured much lower AA values and did not suggest synergism. The use of the LOX/RNO method is useful to unearth new properties of phytochemicals from durum wheat grains, potentially giving health benefits.  相似文献