First Report of Brown Rot Caused by Monilinia polystroma on Apple in Italy

Brown rot is a common apple disease in Italy, caused by Monilinia fructicola, M. laxa and M. fructigena (Martini et al. 2013). In September 2020, in a ‘Jeromine’ apple orchard under integrated pest management located in Scarnafigi (44°39'N, 7°33'E, north-western of Italy), fruits (8.6%) showing brown to blackish firm lesions (6.0 to 8.0 cm diameter) were observed. In some fruits, rots were covered by yellowish stromata. Two isolates (MPI1; MPI2) were obtained from two symptomatic apples and cultured on potato dextrose agar (PDA) for 7 days at 25°C in 12-h light/12-h dark regime. A white-to-greyish mycelium with slightly undulate margins and irregular, black stromata developed on PDA after 12 days incubation. Conidia, observed in branched monilioid chains, (Suppl. Fig. 1) were one-celled, globose, limoniform, hyaline, 38 to 58 μm (mean: 48) × 20 to 44 μm (mean: 33). Based on morphology, the isolates were tentatively identified as Monilinia polystroma (G.C.M. Leeuwen) Kohn. A polymerase chain reaction with primers ITS1 and ITS4 was performed on internal transcribed spacer (ITS) region 1 and 2 and 5.8S gene. The sequenced amplicons (435 bp - 445 bp; GenBank Accession No. MW600854; MW600855) showed 100% identity to the reference isolate of M. polystroma (HQ846944) and to other isolates from apples (AM937114; JX315717) and plum (GU067539). The ITS region of M. polystroma had five nucleotides to distinguish it from the closest species M. fructigena (Zhu et al. 2016; MH862738) (Suppl. Fig. 2). The pathogenicity of both isolates was tested on mature ‘Jeromine’ apples (10.1% total soluble solids). Three replicates of six apples per isolate were surface disinfected with 1% NaClO. A mycelial plug (5 mm) from colony grown on PDA was inserted using a cork borer into a hole (6 mm) in each fruit (Vasić et al. 2016). Apples inoculated with sterile PDA plugs were used as control. Fruits were placed at 22 ± 1 °C, 85% relative humidity and 12 h light/12 h dark regime. Lesion size was measured after 3, 6 and 9 days of incubation. All inoculated fruits developed typical brown rot symptoms 6 days after inoculation and yellowish stromata appeared on the surface; control fruit remained healthy (Suppl. Fig. 3). The virulence of both isolates was statistically similar (Suppl. Table 1). M. polystroma was reisolated from all inoculated fruits and confirmed by molecular methods. This is the first report of M. polystroma on apple in Italy. M. polystroma was previously reported on apple in Hungary (Petróczy et al. 2009), on apricot in Switzerland (Hilber-Bodmer et al. 2012), on peach and pear in Italy (Martini et al. 2014; 2015), on plum in China (Zhu et al. 2016), and on apple in Serbia (Vasić et al. 2018). The emergence of this pathogen for pome and stone fruit production in Europe stimulates to study its biology and epidemiology, and its fitness and management, as compared to the other endemic Monilinia species.

Comparing Biochemical and Raman Microscopy Analyses of Starch, Lipids, Polyphosphate, and Guanine Pools during the Cell Cycle of Desmodesmus quadricauda

Photosynthetic energy conversion and the resulting photoautotrophic growth of green algae can only occur in daylight, but DNA replication, nuclear and cellular divisions occur often during the night. With such a light/dark regime, an algal culture becomes synchronized. In this study, using synchronized cultures of the green alga Desmodesmus quadricauda, the dynamics of starch, lipid, polyphosphate, and guanine pools were investigated during the cell cycle by two independent methodologies; conventional biochemical analyzes of cell suspensions and confocal Raman microscopy of single algal cells. Raman microscopy reports not only on mean concentrations, but also on the distribution of pools within cells. This is more sensitive in detecting lipids than biochemical analysis, but both methods—as well as conventional fluorescence microscopy—were comparable in detecting polyphosphates. Discrepancies in the detection of starch by Raman microscopy are discussed. The power of Raman microscopy was proven to be particularly valuable in the detection of guanine, which was traceable by its unique vibrational signature. Guanine microcrystals occurred specifically at around the time of DNA replication and prior to nuclear division. Interestingly, guanine crystals co-localized with polyphosphates in the vicinity of nuclei around the time of nuclear division.

Breaking of dormancy in the narrow endemic Jasione supina Sieber subsp. supina (Campanulaceae) with small seeds that does not need the light to germinate

The germination properties of Jasione supina Sieber subsp. supina (Campanulaceae), which is endemic to Mount Uludağ, Bursa, Turkey, were determined. In this study, we investigated the effects of GA3, the combination of hormone series and short-term moist chilling (1-month), and long-term moist chilling (4-month) on the germination percentage and mean germination time in relation to seed dormancy breaking. All treatment series were incubated under continuous dark (20 °C, 24 h) and light/dark (20/10 °C, 12/12 h) conditions. Seeds were collected from specimens widespread on alpine and subalpine grasslands and dwarf shrubs of Mount Uludağ (1800-1900 m a.s.l.). Depending on the concentration, GA3 and the combination of hormone and moist chilling treatments promoted seed germination in both dark and light/dark conditions. After 4-month-moist chilling treatment, seeds germinated 27% in light/dark and 80% in dark regime. Hormone and moist chilling treatments reduced the mean germination time. Our results showed that J. supina seeds have physiological dormancy, require prolonged times of moist chilling and preferentially complete germination in darkness.

Control tools to selectively produce purple bacteria for microbial protein in raceway reactors

Purple non-sulfur bacteria (PNSB) show potential for microbial protein production on wastewater as animal feed. They offer good selectivity (i.e. uneven community with high abundance of one species) when grown anaerobically in the light. However, the cost of a closed anaerobic photobioreactor (PBR) is prohibitive for protein production. While open raceway reactors are cheaper, their feasibility to selectively grow PNSB is thus far unexplored. This study developed tools to boost PNSB abundance in the biomass of a raceway reactor fed with volatile fatty acids as carbon source. For oxygen availability as tool, not stirring in the night (i.e. reduced oxygen supply) elevated the PNSB abundance from 8% to 20%. For light availability as tool, a 24-h illumination increased the PNSB abundance from 8% to 31% compared to a 12-h light/12-h dark regime. A reactor run at 2-d sludge retention time at the highest surface-to-volume ratio (10 m2 m-3 increased light availability) showed productivities up to 0.2 g protein L-1 d-1 and the highest PNSB abundance (78%). The estimated production cost is €1.9 kg-1 dry weight (vs. PBR €11.4 kg-1 dry weight). This study pioneered in PNSB-based microbial protein production in raceways, yielding cost efficiency along with high selectivity when avoiding the combined availability of oxygen, COD and darkness.Graphical abstract

Effect of Environmental Factors on Seed Germination and Early Seedling Emergence of Carolina geranium (Geranium carolinianum)

ABSTRACT: Carolina geranium (Geranium carolinianum) is an emerging invasive weed in rape and wheat fields in China. A better understanding of its germination and emergence ecology will enable the development of integrated weed control strategies. In this study, we investigated the effects of temperature, photoperiod, soil water content, salinity, and burial depth, on germination and emergence of Carolina geranium. Germination percentages were over 74% under 15/20 and 20/25 oC night/day temperature regimes. Germination rate was independent of light/dark regime. Increasing salinity reduced germination of Carolina geranium from 81.1% at 0 mM to 0% at 160 mM NaCl. Seeds germination was peaked at 50% soil moisture, but was completely inhibited at < 20% and > 90%. The seedling emergence above 82.2% was observed when seeds were placed at a depth from 0 to 1 cm, and no seedlings emerged from seeds placed at a depth of 7 cm. Current work provide the basic information to effectively prevent and control this invasive weed in Chinese rape and wheat fields.

Seed Germination, Seedling Emergence, and Response to Herbicides of Triquetrous Murdannia (Murdannia triquetra) in Rice

Triquetrous murdannia is an annual weed commonly found in rice fields in China. Laboratory and screenhouse experiments were carried out to determine the effect of light, temperature, osmotic and salt stress, seed burial depth, amount of rice residue, and depth of flooding on seed germination and seedling emergence of triquetrous murdannia and to evaluate the response of this weed to commonly available POST herbicides in China. Germination was greater than 93% under a wide day/night temperature range of 20/10 to 30/20 C in the light/dark regime. The time to onset of germination decreased as temperature increased. Germination was slightly stimulated when seeds were placed in light/dark conditions compared with seeds placed in the dark. The osmotic potential and NaCl concentration required for 50% inhibition of maximum germination were −0.5 MPa and 122 mM, respectively. The highest germination (68%) was observed from seeds sown on the soil surface, but decreased with increasing burial depth. Only 7% of seedlings emerged from a depth of 4 cm, and no seedlings emerged from seeds buried deeper than 6 cm. Seedling emergence decreased from 93 to 35% with increasing quantity of rice residue (1 to 6 103kg ha−1) applied on the soil surface. Seedling emergence was reduced by 40, 48, 64, and 70% at flooding depths of 1, 2, 4, and 6 cm, respectively, for the seeds sown on the soil surface. Fluroxypyr and MCPA herbicides provided 100% control of triquetrous murdannia at the 2- to 6-leaf stages; however, to achieve 100% control with bispyribac-sodium, MCPA+bentazone or MCPA+fluroxypyr, herbicides had to be applied by the 4-leaf stage. The results of this study could help in developing more sustainable and effective integrated weed management strategies for the control of triquetrous murdannia in rice fields in China.

El patrimonio cultural histórico arquitectónico costarricense: una deuda constitucional

ResumenLa formulación del artículo 89 de la Constitución Política de Costa Rica se basa en un Estado Social, no Cultural, de Derecho. La cultura se refiere como un fin de la política y no como un bien jurídico, objeto de tutela, lo cual parece restarle importancia a los intereses jurídicos. En esta línea, la norma constitucional refleja la ausencia de un núcleo conceptual mínimo en torno al patrimonio, cuya tutela resulta, entonces, difusa. Dicha omisión –que conlleva la reducción de un valor histórico arquitectónico a uno artístico— limita tanto el interés cultural, en general, como el arquitectónico, en específico. Con el fin de facilitar la comprensión del (oscuro) régimen tutelar existente, dispuesto en la Ley de Patrimonio Histórico Arquitectónico Nº7555 (1995) y su Reglamento (2005), el artículo revisa el concepto jurídico de patrimonio en dos direcciones: primero, la constitucionalización de los bienes culturales patrimoniales (sección A); segundo, la objetivación de lo cultural en general, y de lo histórico arquitectónico en particular, a la luz del interés jurídico (sección B). Dicho examen permite delinear un concepto integrador del patrimonio cultural y dentro de este, del histórico arquitectónico; lo cual, en última instancia, podría favorecer su tutela. AbstractThe Article 89 of the Politic Constitution of Costa Rica is based on a Social State, not a Cultural State of Law. Culture refers to as a political and not a legal right, subject to protection, which seems to belittle the legal interests. In this line, the constitutional provision reflects the absence of a minimum conceptual core around heritage, whose protection is then diffused. This omission involves the reduction of an architectural historical value to an artistic one, limiting cultural interest in general and the architectural, specifically. In order to facilitate understanding of the (dark) regime tutelary existing provisions of the Law of Historical Heritage Architectural Nº7555 (1995) and Regulations (2005), the article reviews the legal concept of heritage in two directions: first, the constitutionalization of heritage cultural property (section A); second, the objectification of culture in general, and the historical architecture in particular, in the light of legal interest (section B). This examination allows delineate an integrative concept of cultural heritage and within this, the architectural history; which ultimately could favor their protection.

Influence of Photoperiod Duration and Phloem Disruption through Scoring on Growth, Disease Symptoms, and Bacterial Titer in Citrus Graft Inoculated with Candidatus Liberibacter asiaticus

Plants inoculated with the huanglongbing (HLB)-associated bacterium, Candidatus Liberibacter asiaticus (CLas) typically must be monitored for 8–10 months to identify differences in susceptibility between genotypes. Continuous light is reported to accelerate development of HLB symptoms and field observations suggest that trees girdled by tags or tree ties showed greater symptoms. Therefore, an experiment was conducted assessing HLB susceptibility as influenced by light/dark periods of 12 hours: 12 hours and 24 hours: 0 hours, in combination with scoring tree trunks to disrupt phloem. Sixty trees of each of three citrus genotypes (‘Kuharske’, previously shown to be HLB resistant; rough lemon, previously shown to be HLB tolerant; and ‘Valencia’, highly HLB susceptible) were bud grafted using two CLas-infected buds (rough lemon and citron) per tree on 26 Mar. 2012, and were placed in controlled growth rooms (one 12 hour light: 12 hour dark and one constant light) on 4 June 2012. Ten trees of each genotype in each growth room were scored 10 cm above the soil (cutting through the bark but not the wood) with a knife on 18 July 2012 and the scoring was repeated at the same scoring wounds on 30 Aug. 2012. Trees were removed from growth rooms on 12 Dec. 2012 and subsequently maintained in a greenhouse. At two to three month intervals between June 2012 and May 2013, HLB symptoms and stem diameter at 5 cm above the soil were assessed, and three leaves per tree were collected for quantitative polymerase chain reaction (qPCR) determination of CLas titer. Six months after inoculation and 3 months following imposition of treatments, the ‘Valencia’ scored in the 12 hour light: 12 hour dark regime, the ‘Valencia’ non scored trees in 24 hours of light and the ‘Kuharske’ scored trees in 24 hours of light displayed higher CLas titers than most other trees. After an additional two months, both scored and non-scored trees of all three genotypes in 24 hours of light had significantly elevated CLas titers compared with trees in 12 hour light: 12 hour dark regime, but within most treatments all three genotypes had titers which were not statistically different from each other. Growth of ‘Kuharske’ and rough lemon was enhanced; whereas ‘Valencia’ growth was reduced when graft-inoculated plants were maintained in continuous light. Scoring enhanced early CLas development in ‘Kuharske’ when combined with continuous light, had no effect in rough lemon, and showed inconsistent effects in ‘Valencia’. Although continuous lighting enhanced disease progression, it did not reveal differences in HLB susceptibility.

Seed Germination Ecology of Doveweed (Murdannia nudiflora)and Its Implication for Management in Dry-Seeded Rice

This study was conducted in the laboratory and screenhouse to determine the effects of temperature, light, osmotic stress, salt stress, burial depth, use of crop residues as mulch, depth of flooding, and use of POST herbicides on the emergence, survival, and growth of doveweed. In the light/dark regime, germination was higher at alternating day/night temperatures of 35/25 C (95%) than at 30/20 C (72%), and no germination occurred at 25/15 C. Light strongly influenced germination (95%) and dark completely inhibited germination. No germination occurred at an osmotic potential of −0.8 MPa and a salt concentration of 150 mM and above. The highest germination (91%) was observed from the seeds sown on the soil surface and emergence decreased by 78, 86, and 92% when burial depths were increased to 0.5, 1, and 2 cm, respectively. No seedlings emerged from seeds buried at depths of more than 2 cm. The use of rice residues as mulch significantly reduced the emergence and growth of doveweed seedlings. The amount of residue required to suppress 50% of the maximum biomass was 2.5 t ha−1. Flooding had a more pronounced effect on seedling biomass than seedling emergence. Biomass was reduced by 78, 92, and 96% when flooding depths increased from 0 to 2, 4, and 6 cm, respectively, for the seeds placed on the soil surface, whereas for the seeds buried at 0.5 cm, these values were 78, 100, and 100%. Bentazon (100 g ha−1) and bispyribac-sodium (30 g ha−1) provided 100% control of doveweed when applied at the three-leaf stage. Doveweed control was less than 31% with glyphosate rates up to 2,000 g ha−1. The application of 2,4-D (500 g ha−1) provided 100% control of doveweed even when applied at the seven-leaf stage. The information from this study could help in developing more sustainable and effective integrated weed management strategies for the control of this weed and weeds with similar response in dry-seeded rice systems.