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Phytophthora cinnamomi Rands is a highly prevalent phytopathogen worldwide, ranking among the top ten in terms of distribution. It inflicts crown rot, canker, and root rot on numerous plant species, significantly impacting the biodiversity of both flora and fauna within affected environments. With a host range spanning over 5,000 species, including important plants like Quercus suber, Quercus ilex, Castanea sativa, and commercially significant crops such as avocado (Persea americana), maize (Zea mays), and tomato (Solanum lycopersicum), Phytophthora cinnamomi poses a substantial threat to agriculture and ecosystems. The efficient dissemination of the oomycete relies on its short-lived asexually motile zoospores, which depend on water currents to infect host roots. However, managing these zoospores in the laboratory has long been challenging due to the complexity of the life cycle. Current protocols involve intricate procedures, including alternating cycles of growth, drought, and flooding. Unfortunately, these artificial conditions often result in a rapid decline in virulence, necessitating additional steps to maintain infectivity during cultivation. In our research, we sought to address this challenge by investigating zoospore survival under various conditions. Our goal was to develop a stable stock of zoospores that is both easily deployable and highly infective. Through direct freezing in liquid nitrogen, we have successfully preserved their virulence. This breakthrough eliminates the need for repeated culture transfers, simplifying the process of plant inoculation. Moreover, it enables more comprehensive studies of Phytophthora cinnamomi and its interactions with host plants.

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The predatory mites of the Phytoseiidae family are crucial biological control agents widely utilized in biological pest management targeting phytophagous mites and insects. Key factors in these control strategies are that phytoseiids must be able to find their main target prey and to maintain high populations and efficacy. To reduce expenses and time-consuming production methods of mass rearing of phytoseiids, pollen and other factitious (i.e., non-natural/nontarget) hosts need to be present as an alternative food for predatory mite populations. The mass-rearing possibilities of these predators on alternative food sources, such as astigmatid mites (i.e., house and stored mites) and pollen, must be evaluated not only by the cost of rearing settings but on the basis of their efficiency maintenance in killing prey. The pest kill rate (km) is the average daily lifetime killing of the pest by the natural enemy under consideration and can represent a useful indicator for phytoseiids efficacy to rank them as BCAs on the basis of their effective killing/predation on target prey. In this study, we evidenced that 2 astigmatid mites, Glycyphagus domesticus (De Geer) and Lepidoglyphus destructor (Schrank), and Quercus ilex L. pollen can be successfully adopted as substitute food sources for mass rearing of the phytoseiid Neoseiulus californicus (MgGregor); then, we determined that these populations of BCAs maintained a consistent km at new/first impact on the main target pest, Tetranychus urticae Koch.

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A novel endophytic actinomycete, designated strain NEAU-365T, was isolated from the root of Quercus variabilis collected from Nanjing, Jiangsu, PR China. Comparative 16S rRNA gene sequencing showed that strain NEAU-365T belonged to the genus Mumia but clearly differs from the currently recognized species Mumia zhuanghuii Z350T (99.31 %), Mumia xiangluensis NEAU-KD1T (98.82 %) and Mumia flava MUSC 201T (97.78 %). Phylogenetic tree analysis revealed that strain NEAU-365T clustered with the type strains of the genus Mumia. The genome size was 4.1 Mbp with a DNA G+C content of 71.2 mol%. Digital DNA-DNA hybridization and average nucleotide identity values between the genome sequence of strain NEAU-365T and those of M. zhuanghuii Z350T(27.5 and 84.0 %), M. xiangluensis NEAU-KD1T(23.4 and 80.9 %) and M. flava MUSC 201T(20.9 and 77.7 %) were below the recommended thresholds for species delineation. Cells were observed to be irregular cocci shaped. The cell wall contained ll-diaminopimelic acid and the whole-cell sugars were galactose and rhamnose. The polar lipids consisted of diphosphatidylglycerol, phosphatidylglycerol, phosphoglycolipid and three unidentified phospholipids. The predominant menaquinone was detected as MK-9(H4). The major fatty acids were C16 : 0, C18 : 0, C18 : 1 ω9c and 10-methyl C18 : 0. On the basis of genotypic and phenotypic differences from members of the genus Mumia, a novel species, Mumia quercus sp. nov. is proposed. The type strain is NEAU-365T (=CCTCC AA 2021033T=JCM 35005T).

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Fern spores and pollen are haploid plant germplasm of microscopic nature that can be used to regenerate full plants through germination (fern spores) or to fertilize seed-bearing plants through breeding programs (pollen). Due to their short life span in conventional storage (i.e., dry at -20 °C), the use of cryopreservation has been indicated for long-term ex situ conservation. While fern spores of most species and pollen from many seeded plants tolerate desiccation and can be stored dry at liquid nitrogen temperatures, some pollen is desiccation sensitive, and cryopreservation protocols require controlled drying and cooling and some level of cryoprotection. In this chapter we describe the cryopreservation process for fern spores used in the Millennium Seed Bank of Royal Botanic Gardens, Kew, including some details of the fern spores harvest and cleaning methods. In addition, two protocols for pollen cryopreservation are described, one generic for desiccation-tolerant pollen that can be used for multiple species and one specific for a desiccation sensitive pollen (Zea mays).

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Seeds are one of the preferable and most used sources of germplasm for the ex situ preservation of plant genetic resources. They are generally stored dry at -20 °C in seed banks following international standards. However, some seeds do not tolerate drying and/or storage at -20 °C, or present short lifespans at these conditions. For them cryopreservation is indicated for long-term preservation. When seeds tolerate desiccation (i.e., orthodox seeds), they can be dried at about 32 ± 3% relative humidity at 18 °C and stored in the vapor phase of liquid nitrogen. This is the method followed in the Millennium Seed Bank of the Royal Botanic Gardens, Kew, for wild species with short lifespans in the standard conditions of seed banks. When seeds do not tolerate desiccation (i.e., recalcitrant seeds) or their tolerance to desiccation and/or -20 °C storage is limited (i.e., intermediate seeds), drying and cooling procedures must be adjusted, and often, cryoprotection is also required. Some methods are detailed for diverse species of temperate and tropical origin.

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Novel aerobic, restricted facultatively methylotrophic bacteria were isolated from buds of English oak (Quercus robur L.; strain DubT) and northern red oak (Quercus rubra L.; strain KrD). The isolates were Gram-negative, asporogenous, motile short rods that multiplied by binary fisson. They utilized methanol, methylamine and a few polycarbon compounds as carbon and energy sources. Optimal growth occurred at 25 °C and pH 7.5. The dominant phospholipids were phosphatidylethanolamine, phosphatidylcholine, diphosphatidylglycerol and phoshatidylglycerol. The major cellular fatty acids of cells were C18 : 1 ω7c, 11-methyl C18 : 1 ω7c and C16 : 0. The major ubiquinone was Q-10. Analysis of 16S rRNA gene sequences showed that the strains were closely related to the members of the genus Hansschlegelia: Hansschlegelia zhihuaiae S113T(97.5-98.0 %), Hansschlegelia plantiphila S1T (97.4-97.6 %) and Hansschlegelia beijingensis PG04T(97.0-97.2 %). The 16S rRNA gene sequence similarity between strains DubT and KrD was 99.7 %, and the DNA-DNA hybridization (DDH) result between the strains was 85 %. The ANI and the DDH values between strain DubT and H. zhihuaiae S113T were 80.1 and 21.5  %, respectively. Genome sequencing of the strain DubT revealed a genome size of 3.57 Mbp and a G+C content of 67.0 mol%. Based on the results of the phenotypic, chemotaxonomic and genotypic analyses, it is proposed that the isolates be assigned to the genus Hansschlegelia as Hansschlegelia quercus sp. nov. with the type strain DubT (=VKM B-3284T=CCUG 73648T=JCM 33463T).

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The adult male of Allokermes galliformis (Riley, 1881) (Hemiptera: Coccomorpha: Kermesidae) is described for the first time in Colorado, United States of America. This scale insect species recently emerged as a significant pest of red oaks in Colorado through its causative role in drippy blight disease. A description and illustration of the adult male characterize its key external morphological characteristics.

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Determining appropriate management strategies to reduce greenhouse gas emissions using optimization techniques to understand how forest management activities affect the carbon dynamics is critical in implementing effective carbon management policies. This paper quantitatively analyzes the long-term effects of different management policies and silvicultural interventions using linear programming. In the analyses, afforestation targets for bare forest lands, tree species, carbon prices, planning approaches and sets of various targets and constraints on carbon dynamics were evaluated. The results were based on twenty-five forest management scenarios formulated for the Korucu Forest Planning Unit of Turkey. The results showed that, compared to timber-based planning strategies (TM), ecosystem-based planning approach (EM) contributes to a significant reduction in carbon sequestration in many cases. When different afforestation targets were incorporated into forest management strategies, cumulative carbon sequestration increased constantly compared to baseline scenario without any afforestation areas. In addition, the highest total carbon sequestration was observed when black pine (P. nigra) was used in afforestation activities rather than oak species (Quercus sp.) and other available tree species. While total timber production and timber net present value (NPV) decreased, carbon sequestration increased significantly with increasing carbon price. As a result of increasing carbon price from $20/ton to $100/ton, joint NPV increased by about five times. The results highlighted the importance of forest ecosystem and developing and implementing climate adaption measures into forest management activities in tackling climate change phenomenon.

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We reconstructed the contamination history of an area influenced by 40 years of uranium mining and subsequent remediation actions using dendroanalysis (i.e., the determination of the elemental content of tree rings). The uranium content in the tree rings of four individual oak trees (Quercus sp.) was determined by laser ablation with inductively coupled plasma mass spectrometry (LA-ICP-MS). This technique allows the investigation of trace metals in solid samples with a spatial resolution of 250 µm and a detection limit below 0.01 µg/g for uranium. The investigations show that in three of the four oaks sampled, there were temporally similar uranium concentrations. These were approximately 2 orders of magnitude higher (0.15 to 0.4 µg/g) than those from before the period of active mining (concentrations below 0.01 µg/g). After the mining was terminated and the area was restored, the uranium contents in the wood decreased by approximately 1 order of magnitude. The similar radial uranium distribution patterns of the three trees were confirmed by correlation analysis. In combination with the results of soil analyses, it was determined that there was a heterogeneous contamination in the forest investigated. This could be confirmed by pre-remediation soil uranium contents from literature. The uranium contents in the tree rings of the oaks investigated reflect the contamination history of the study area. This study demonstrates that the dendrochemical analysis of oak tree rings is a suitable technique for investigating past and recent uranium contamination in mining areas.

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