A new set of international Leptosphaeria maculans isolates as a resource for elucidation of the basis and evolution of blackleg disease on Brassica napus

© 2023 The Authors. Plant Pathology published by John Wiley & Sons Ltd on behalf of British Society for Plant Pathology. This is an open access article under the terms of the Creative Commons Attribution-Non Commercial-No Derivs License. https://creativecommons.org/licenses/by-nc-nd/4.0/A collection of isolates of the fungi Leptosphaeria maculans and L. biglobosa, which cause blackleg disease on Brassica napus (canola/oilseed rape) and other Brassicaceae species, was assembled to represent the global diversity of these pathogens and a resource for international research. The collection consists of 226 isolates (205 L. maculans and 21 L. biglobosa) from 11 countries. The genomes of all 205 L. maculans isolates were sequenced, and the distribution and identity of avirulence gene alleles were determined based on genotypic information and phenotypic reactions on B. napus lines that hosted specific resistance genes. Whilst the frequencies of some avirulence alleles were consistent across each of the regions, others differed dramatically, potentially reflecting the canola/oilseed rape cultivars grown in those countries. Analyses of the single-nucleotide polymorphism (SNP) diversity within these L. maculans isolates revealed geographical separation of the populations. This "open access" resource provides a standardized set of isolates that can be used to define the basis for how these fungal pathogens cause disease, and as a tool for discovery of new resistance traits in Brassica species.Peer reviewe

Evaluation of storm impact on sandy beaches of the Gulf of Valencia using Landsat imagery series

Supplementary data associated with this article can be found in the online version, at http://dx.doi.org/10.1016/j.geomorph.2014.02.020. These data include Google maps of the most important areas described in this article.The impact of storms on sandy beaches and the subsequent recovery process is described from an analysis of the shoreline positions obtained from Landsat 5 TM and Landsat 7 ETM + imagery. Shoreline extraction is based on an algorithm previously proposed by the authors that enables a positioning accuracy of 5 m root mean square error (RMSE). The impact of six storms registered over a period of seven months (between November 2001 and May 2002) and the beach recovery processes until December 2002 across a 100 km segment of the Gulf of Valencia on the Spanish Mediterranean coast were analysed by comparing 12 shoreline positions. The multiple shoreline positions obtained from Landsat images provide very useful information for describing the impact of storms and the recovery process across large segments of microtidal coast. This enables the identification of differences not only in the magnitude of change produced by a particular event but also in the cumulative effect associated with several storm events, and in the study of how the beach recovery process takes place. The results show a high level of spatial variability. Beaches with steep slopes experienced fewer changes than shallow slopes. The existence of well developed foredunes in some areas minimised the reduction in the beach width after the storms. Coastal orientation was another important factor in explaining storm impact and the recovery process. This factor affects not only the way the waves interact with the beaches but also the sediment longshore transport: beach regeneration is slower when the transport of sediments is limited by artificial infrastructures (groins, jetties, ports) or natural sediment traps (headlands). The main limitations of using the proposed methodology to obtain the shoreline position from Landsat images are related to: (i) the precision in the shoreline detection; (ii) the nature of the indicator obtained, that is, the water/land interface; and (iii) the registration instant defined by the image acquisition time. However, the high frequency of the data acquisition and the possibility to cover large coastal areas bring a new perspective that enriches other methods and tools used by coastal scientists.The authors appreciate the financial support provided by the Spanish Ministerio de Ciencia e Innovacion in the framework of the Projects CGL2009-14220-C02-01 and CGL2010-19591. We also thank the Direccion General de Costas in Valencia for making available the data for the tests and analysis. Finally, we would like to thank the useful suggestions provided by the anonymous referees and the assigned editor, which enabled us to improve the quality of this paper.Pardo Pascual, JE.; Almonacid Caballer, J.; Ruiz Fernández, LÁ.; Palomar-Vázquez, J.; Rodrigo-Alemany, R. (2014). Evaluation of storm impact on sandy beaches of the Gulf of Valencia using Landsat imagery series. Geomorphology. 214:388-401. doi:10.1016/j.geomorph.2014.02.020S38840121

Mortality and pulmonary complications in patients undergoing surgery with perioperative SARS-CoV-2 infection: an international cohort study

Background: The impact of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) on postoperative recovery needs to be understood to inform clinical decision making during and after the COVID-19 pandemic. This study reports 30-day mortality and pulmonary complication rates in patients with perioperative SARS-CoV-2 infection. Methods: This international, multicentre, cohort study at 235 hospitals in 24 countries included all patients undergoing surgery who had SARS-CoV-2 infection confirmed within 7 days before or 30 days after surgery. The primary outcome measure was 30-day postoperative mortality and was assessed in all enrolled patients. The main secondary outcome measure was pulmonary complications, defined as pneumonia, acute respiratory distress syndrome, or unexpected postoperative ventilation. Findings: This analysis includes 1128 patients who had surgery between Jan 1 and March 31, 2020, of whom 835 (74·0%) had emergency surgery and 280 (24·8%) had elective surgery. SARS-CoV-2 infection was confirmed preoperatively in 294 (26·1%) patients. 30-day mortality was 23·8% (268 of 1128). Pulmonary complications occurred in 577 (51·2%) of 1128 patients; 30-day mortality in these patients was 38·0% (219 of 577), accounting for 81·7% (219 of 268) of all deaths. In adjusted analyses, 30-day mortality was associated with male sex (odds ratio 1·75 [95% CI 1·28–2·40], p\textless0·0001), age 70 years or older versus younger than 70 years (2·30 [1·65–3·22], p\textless0·0001), American Society of Anesthesiologists grades 3–5 versus grades 1–2 (2·35 [1·57–3·53], p\textless0·0001), malignant versus benign or obstetric diagnosis (1·55 [1·01–2·39], p=0·046), emergency versus elective surgery (1·67 [1·06–2·63], p=0·026), and major versus minor surgery (1·52 [1·01–2·31], p=0·047). Interpretation: Postoperative pulmonary complications occur in half of patients with perioperative SARS-CoV-2 infection and are associated with high mortality. Thresholds for surgery during the COVID-19 pandemic should be higher than during normal practice, particularly in men aged 70 years and older. Consideration should be given for postponing non-urgent procedures and promoting non-operative treatment to delay or avoid the need for surgery. Funding: National Institute for Health Research (NIHR), Association of Coloproctology of Great Britain and Ireland, Bowel and Cancer Research, Bowel Disease Research Foundation, Association of Upper Gastrointestinal Surgeons, British Association of Surgical Oncology, British Gynaecological Cancer Society, European Society of Coloproctology, NIHR Academy, Sarcoma UK, Vascular Society for Great Britain and Ireland, and Yorkshire Cancer Research

Estudio in vitro de microfiltración marginal en restauraciones indirectas cementadas con cemento dual y resinas fluidificadas por precalentamiento.

Objectives: To determine in vitro if there is a difference in the marginal microfiltration of composite resin inlays, cemented with dual resin cement and fluidized composite by preheating, evaluated with macrophotographs at the Private University of Huancayo Franklin Roosevelt 2018 - 2019. Material and Methods: In vitro experimental type, quasi-experimental design. Results: It was found that of the inlays cemented with dual resin cement and with fluidized composite resin, they presented the highest percentages: 80% and 70% respectively at the “medium level of microleakage”, in terms of “absence of microleakage”, the fluidized resin had 5% as opposed to 0% of dual cement, and the “high microleakage” level was present only in the 10% dual cement cemented inlays and both equaled 0% in “very high” grade microleakage. Noting a slight superiority in terms of the lower presence of microleakage in the inlays cemented with fluidized composite resins. Conclusions: It was determined that there is a significant difference between the marginal microleakage of mesio-occluso-distal composite resin inlays cemented with dual resin cement and cemented with composite resin fluidized by preheating, evaluated with macrophotographs. Chi square of 0.325 and a p <significance level α (0.000 <0.05).Objetivos: Determinar in vitro si existe diferencia en la microfiltración marginal de incrustaciones de resina compuesta, cementadas con cemento resinoso dual y resina compuesta fluidificada por precalentamiento, evaluadas con macrofotografías en la Universidad Privada de Huancayo Franklin Roosevelt 2018 – 2019. Material y Métodos: Tipo experimental in vitro, diseño cuasi experimental. Resultados: Se halló que de las incrustaciones cementadas con cemento resinoso dual y con resina compuesta fluidificada presentaron los más altos porcentajes: 80% y 70% respectivamente en el nivel “medio de microfiltración”, en cuanto a la “ausencia de microfiltración” la resina fluidificada tuvo un 5% a diferencia del 0% del cemento dual, y el nivel “alto de microfiltración” estuvo presente solo en las incrustaciones cementadas con cemento dual con un 10% y ambos igualaron con 0% en microfiltración de grado “muy alto”. Notándose una leve superioridad en cuanto a la menor presencia de microfiltración en las incrustaciones cementadas con resinas compuestas fluidificadas. Conclusiones: Se determinó que existe diferencia significativa entre la microfiltración marginal de incrustaciones mesio-ocluso-distales de resina compuesta cementadas con cemento resinoso dual y cementadas con resina compuesta fluidificada por precalentamiento, evaluadas con macrofotografías. Chi cuadrada de 0,325 y un p < nivel de significancia α (0,000 < 0,05)

Sclerotinia sclerotiorum Populations Infecting Canola from China and the United States Are Genetically and Phenotypically Distinct

Genetic and phenotypic diversity and population differentiation of Sclerotinia sclerotiorum isolates infecting canola from China and the United States were investigated. Genetic diversity was assessed with eight microsatellite markers and mycelial compatibility groups (MCGs). Phenotypic diversity was assessed with sensitivity to three fungicides, production of oxalate and sclerotia, growth rate, and virulence on two canola cultivars. No shared MCGs or multilocus haplotypes were detected between the two populations, and populations differed significantly (P &lt; 0.001). Recombination was detected in both populations but was greater in the Chinese population. A polymerase chain reaction detection assay showed that ~60% of the isolates were inversion-plus at the mating type locus. The two populations differed significantly (P &lt; 0.05) for all of the phenotypic traits except for sensitivity to fungicide fluazinam and virulence. Isolates in the Chinese population were unique in several aspects. Despite the phenotypic differentiation, heritabilities of the phenotypic traits were similar for both populations. Significant correlations were found among five phenotypic traits. Cross resistance to benomyl and iprodione was detected. Virulence was not significantly correlated with any other phenotypic trait and had the least heritability. However, both populations were equally virulent on either a susceptible or a moderately resistant canola cultivars. </jats:p

Efficacy of different inoculum forms of Rhizoctonia solani AG 2 2IIIB for resistance screening of sugar beet varieties

© 2023, This is a U.S. Government work and not under copyright protection in the US; foreign copyright protection may apply. This is the accepted manuscript version of an article which has been published in final form at https://doi.org/10.1007/s42161-023-01485-zSugar beet (Beta vulgaris L.) is one of the major sugar sources in the world. Rhizoctonia solani causes damping-off and crown and root rot that can result in significant yield and economic losses. R. solani AG 2–2 IIIB is the most damaging anastomosis group in sugar beet production. In this study, we evaluated three different types of inoculums, namely barley grains colonized by fungal mycelium (CBG), agar plugs containing fungal mycelia (MAP), and sclerotia (SCL) for their ease of production and efficacy in inducing disease in sugar beet. First, the fungal growth rate and sclerotia production were compared on six types of media, clarified V8 [CV8], potato dextrose agar [PDA], metalaxyl benomyl vancomycin agar [MBV], yeast malt agar [YMA], corn meal agar [CMA], and oatmeal agar [OMA]. The fungus grew faster and produced more sclerotia in CV8 medium than in other media (P < 0.05). The rate of fungal growth from CBG, MAP, and SCL was evaluated. The in vitro rate of growth of R. solani was faster when originated from MAP than from SCL (P < 0.05) but equal to that from CBG. The different inoculum forms were then used to inoculate seeds at planting and 4-leaf stage sugar beet plants to evaluate the disease incidence and severity. R. solani on CBG caused greater severity. Overall, CBG was the best form of inoculum due to its ease of inoculum production, low cost, and ability to consistently cause severe disease symptoms on sugar beet plants.Peer reviewe

Evaluation of adjuvants added to fungicides for controlling Cercospora leaf spot on sugar beet

© 2023 Elsevier Ltd. All rights reserved. This is the accepted manuscript version of an article which has been published in final form at https://doi.org/10.1016/j.cropro.2023.106471Cercospora Leaf Spot (CLS) is a destructive foliar disease of sugar beet caused by Cercospora baticola. Recent development of resistance to several classes of chemicals by C. beticola coupled with untimely applications and/or frequent rainfall after fungicide applications have resulted in reduced efficacy of fungicides in controlling CLS. Adjuvants are typically included in fungicide formulations as inert ingredients to improve retention, delivery, and efficacy against targeted pathogens. In the greenhouse trials, three recommended fungicides (Penncozeb®, Inspire® XT, and Badge® SC) were applied and evaluated alone or in mixtures with four adjuvant types (Complex®, Preference®, Cerium Elite®, and Transfix®) before and after inoculation with C. beticola. Disease severity was recorded 14 days post-inoculation. Greenhouse trials showed that application of fungicides before disease onset resulted in reduced disease severity. Inspire XT had lower disease severity than Penncozeb or Badge SC. Adjuvants alone were not effective at controlling CLS. Among all fungicide-adjuvant combinations, only Complex and Inspire resulted in lowest disease severity. In the field trials, fungicides were applied alone or with three adjuvants. Disease severity was evaluated at 14 days intervals and recoverable sucrose (i.e., sugar yield) was measured at harvest. Field trials showed significant variations between years in disease severity and sugar yield (P < 0.001). These variations may be caused by lack of rain events immediately after the fungicide application or during the following two days. The finding that addition of adjuvants did not improve the efficacies of fungicides at controlling CLS was because if there was no rain, then the adjuvants should not be any better than formulated fungicide. Thus, more experiments are necessary with similar and different adjuvant-fungicide combinations.Peer reviewe

Evaluating inoculation methods to infect sugar beet with Fusarium oxysporum f. Betae and F. Secorum

Funding Information: Funding: This research was partially supported by the Sugarbeet Research and Education Board of Minnesota and North Dakota. Publisher Copyright: © 2020 The American Phytopathological SocietyMinnesota and North Dakota combined contain 55% of the sugar beet production area in the United States, contributing to 49% of the nation's sugar beet production in 2018. Fusarium diseases caused by Fusarium oxysporum f. betae and F. secorum on sugar beet can cause significant reduction in both root yield and sucrose concentration and purity. The objective of this research was to identify an alternative artificial inoculation method to induce Fusarium diseases on sugar beet leaves and roots caused by both Fusarium spp. in greenhouse conditions to better aid in research efforts. We tested four inoculation methods, including barley to seed, barley to root, drenching, and cutting. and compared them with the conventional root-dipping inoculation method. The inoculation method of placing Fusarium-colonized barley seed close to sugar beet seed (barley to seed) caused levels of symptom severities on both leaves and roots similar to the root-dipping method. Because the traditional root-dipping method involves a laborious transplant process, use of infected barley seed as inoculum may serve as an alternative method in the evaluation of host resistance and pathogen virulence among Fusarium diseases by Fusarium spp. on sugar beet at the seed or seedling stage.Peer reviewe

Resistance to QoI and DMI Fungicides Does Not Reduce Virulence of C. beticola Isolates in North Central United States

© 2023 The American Phytopathological Society. This is the accepted manuscript version of an article which has been published in final form at https://doi.org/10.1093/mnras/stad557Cercospora leaf spot (CLS) is a destructive disease limiting sugar beet production and managed using resistant cultivars, crop rotation, and timely applications of effective fungicides. Since 2016, its causal agent, Cercospora beticola, has been reported to be resistant to Quinone outside inhibitors (QoIs) and to have reduced sensitive to Demethylation inhibitors (DMIs) in sugar beet growing areas in North Dakota and Minnesota. Isolates of C. beticola resistant to QoIs, DMIs, and both QoIs and DMIs were collected from Foxhome fields, Minnesota in 2017. Fitness of these resistant isolates was compared to that of QoI- and DMI-sensitive isolates in laboratory and greenhouse studies. In the lab, mycelial growth, spore production, and spore germination were measured. The results showed that resistant isolates had significantly less mycelial growth and spore production than sensitive isolates, while no significant difference in spore germination was detected. In the greenhouse, six leaf-stage sugar beets were inoculated with a spore suspension made from each resistant group and then incubated in separate humidity chambers. CLS disease severity was evaluated visually at 7, 14, and 21 days after inoculation (DAI) and the areas under disease progress curve (AUDPC) were calculated. Resistant isolates had significantly smaller AUDPC but still caused high disease severity as the sensitive ones at 21 DAI. Although QoI and/or DMI resistant isolates had a relatively slower disease development, they still caused high disease severity and need to be factored in disease management practices.Peer reviewe

Selection of haploid cell lines from megagametophyte cultures of maritime pine as a DNA source for massive sequencing of the species

[EN] The potential of haploid tissues for genetic studies in conifers is hampered by the lack of abundant and homogeneous plant material suitable for DNA isolation. In this work we have determined factors promoting haploid callus induction and proliferation from megagametophytes of Oria 6, a genotype of Pinus pinaster Aiton (maritime pine) from the natural population Sierra de Oria (Almeria, Spain), selected based on its response to extreme drought conditions. The generation of haploid callus was restricted to megagametophytes isolated from light-brown cones with no dehydrated seeds collected in September. Culture medium composition did not significantly affect callus induction, but a modified Murashige and Skoog medium with 2,4-dichlorophenoxyacetic acid and 6-benzyladenine favored further multiplication. The ploidy status of the callus lines was determined by flow cytometry and seven polymorphic microsatellites. A total of sixteen haploid callus lines were established and one of these is being used as a source of DNA for massive sequencing of maritime pine genome.Research funds were provided by Spanish National projects (BIO2007-29814 and BIO2010-12302-E) and Generalitat Valenciana (Prometeo/2009/075). The research leading to these results has also received funding from the European Union’s Seventh Framework Programme (FP7/2007–2013) under Grant Agreement No. 289841 (ProCoGen). We thank M. A. Morcillo for technical assistance, Dr. Jose´ Juarez (Instituto Valenciano de Investigaciones Agrarias, IVIA, Spain) and Dr. Vesselina Nikolova (Vegetable Crops Research Institute, Plovdiv, Bulgaria) for their support in the flow cytometry and karyological analyses, respectively.Arrillaga, I.; Guevara, MA.; Muñoz Bertomeu, J.; Lazaro-Gimeno, D.; Saez-Laguna, E.; Diaz, L.; Torralba, L.... (2014). Selection of haploid cell lines from megagametophyte cultures of maritime pine as a DNA source for massive sequencing of the species. Plant Cell, Tissue and Organ Culture. 118(1):147-155. https://doi.org/10.1007/s11240-014-0470-zS1471551181Abacus Concepts (1989) SuperAnova 1.01. Abacus Concepts, BerkeleyAleza P, Juárez J, Hernández M, Pina JA, Ollitrault P, Navarro L (2009) Recovery and characterization of a Citrus clementina Hort. ex Tan. ‘Clemenules’ haploid plant selected to establish the reference whole Citrus genome sequence. BMC Plant Biol 9:110–127Andersen SB (2005) Haploids in the improvement of woody species. In: Palmer CE, Keller WA, Kasha KJ (eds) Haploids in crop improvement II. Biotechnology in agriculture and forestry, vol 56. Springer, Berlin, pp 243–257Aranda I, Alía R, Ortega U, Dantas AK, Majada J (2010) Intra-specific variability in biomass partitioning and carbon isotopic discrimination under moderate drought stress in seedlings from four Pinus pinaster populations. Tree Genet Genomes 6:169–178Azevedo H, Dias A, Tavares RM (2008) Establishment and characterization of Pinus pinaster suspension cell cultures. Plant Cell Tiss Org Cult 93:115–121Baldursson S, Ahuja MR (1996) Haploidy in forest tress. In: Jain MS, Sopory SK, Veilleux RE (eds) In vitro haploid production in higher plants, vol 1. Kluwer, Dordrecht, pp 49–66Baldursson S, Nørgaard J, Krogstrup P (1993) Factors influencing Haploid callus initiation and proliferation in megagametophyte cultures of Sitka spruce (Picea sitchensis). Silvae Genet 42:79–86Birol I, Raymond A, Jackman SD, Pleasance S, Coope R, Taylor GA, Yuen MM, Keeling CI, Brand D, Vandervalk BP, Kirk H, Pandoh P, Moore RA, Zhao Y, Mungall AJ, Jaquish B, Yanchuk A, Ritland C, Boyle B, Bousquet J, Ritland K, Mackay J, Bohlmann J, Jones SJ (2013) Assembling the 20 Gb white spruce (Picea glauca) genome from whole-genome shotgun sequencing data. Bioinformatics 29:1492–1497Blasco M, Barra A, Brisa C, Corredoira E, Segura J, Toribio M, Arrillaga I (2013) Somatic embryogenesis in holm oak male catkins. Plant Growth Regul 71:261–270Bonga JM (1974) In vitro culture of microsporophylls and megagametophyte tissue of Pinus. In Vitro 9:270–278Cao H, Biswas MK, Lü Y, Amar MH, Tong Z, Xu Q, Xu J, Guo W, Deng X (2011) Doubled haploid callus lines of Valencia sweet orange recovered from anther culture. Plant Cell Tiss Organ Cult 104:415–423de Lucas AI, Robledo-Arnuncio JJ, Hidalgo E, González-Martínez SC (2008) Mating system and pollen gene flow in Mediterranean maritime pine. Heredity 100:390–399Dunwell JM (2010) Haploids in flowering plants: origins and exploitation. Plant Biotechnol J 8:377–424Forster BP, Heberle-Bors E, Kasha KJ, Touraev A (2007) The resurgence of haploids in higher plants. Trends Plant Sci 12:368–375Guevara MA, Chagné D, Almeida H, Byrnes M, Collada C, Favre JM, Harvengt L, Jeandroz S, Orazio C, Plomion C, Ramboer A, Rocheta M, Sebastiani F, Soto A, Vendramin GG, Cervera MT (2005) Isolation and characterization of nuclear microsatellite loci in Pinus pinaster Ait. Mol Ecol Notes 5:57–59Humánez A, Blasco M, Brisa C, Segura J, Arrillaga I (2012) Somatic embryogenesis from different tissues of Spanish populations of maritime pine. Plant Cell Tiss Organ Cult 11:373–383Lelu-Walter MA, Bernier-Cardou M, Klimaszewska K (2006) Simplied and improved somatic embriogenesis for clonal propagation or Pinus pinaster (Ait.). Plant Cell Rep 25:767–776Mackay J, Dean JFD, Plomion C, Peterson DG, Cánovas FM, Pavy N, Ingvarsson PK, Savolainen O, Guevara MA, Fluch S, Vinceti B, Abarca D, Díaz-Sala C, Cervera MT (2012) Towards decoding the conifer giga-genome. Plant Mol Biol 80:555–569Murashige T, Skoog F (1962) A revised medium for rapid growth and bioassay with tobacco tissue cultures. Physiol Plant 15:473–497Neale DB, Kremer A (2011) Forest tree genomics: growing resources and applications. Nat Rev Genet 12:111–122Nystedt B, Street NR, Wetterbom A, Zuccolo A, Lin YC, Scofield DG, Vezzi F, Delhomme N, Giacomello S, Alexeyenko A, Vicedomini R, Sahlin K, Sherwood E, Elfstrand M, Gramzow L, Holmberg K, Hällman J, Keech O, Klasson L, Koriabine M, Kucukoglu M, Käller M, Luthman J, Lysholm F, Niittylä T, Olson A, Rilakovic N, Ritland C, Rosselló JA, Sena J, Svensson T, Talavera-López C, Theißen G, Tuominen H, Vanneste K, Wu ZQ, Zhang B, Zerbe P, Arvestad L, Bhalerao R, Bohlmann J, Bousquet J, Gil RG, Hvidsten TR, de Jong P, MacKay J, Morgante M, Ritland K, Sundberg B, Thompson SL, Van de Peer Y, Andersson B, Nilsson O, Ingvarsson PK, Lundeberg J, Jansson S (2013) The Norway spruce genome sequence and conifer genome evolution. Nature 497:579–584Ochatt SJ, Patat-Ochatt EM, Moessner A (2011) Ploidy level determination within the context of in vitro breeding. Plant Cell Tiss Org Cult 104:329–341Owens JN, Kittirat T, Mahalovich MF (2008) Whitebark pine (Pinus albicaulis Engelm.) seed production in natural stands. For Ecol Manag 255:803–809Pattanavibool R, von Aderkas P, Hanhijärvi A, Simola LK, Bonga JM (1995) Diploidization in megagametophyte-derived cultures of the gymnosperm Larix decidua. Theor Appl Genet 90:671–674Pichot C, El Maataoui M (1997) Flow cytometric evidence for multiple ploidy levels in the endosperm of some gymnosperm species. Theor Appl Genet 94:865–870Ravi M, Chan SWL (2010) Haploid plants produced by centromere-mediated genome elimination. Nature 464:615–619Sánchez-Gómez D, Majada J, Alía R, Feito I, Aranda I (2010) Intraspecific variation in growth and allocation patterns in seedlings of Pinus pinaster Ait. Ann For Sci 67:505p1–505p8 (submitted to contrasting watering regimes: can water availability explain regional variation?)Sederoff R (2013) A spruce sequence. Nature 497:569–570Simola LK, Santanen A (1990) Improvement of nutrient medium for growth and embryogenesis of megagametophyte and embryo callus lines of Picea abies. Physiol Plant 80:27–35Tukey JW (1953) Some selected quick and easy methods of statistical analysis. Trans NY Acad Sci 16:88–97von Aderkas P, Bonga JM (1988) Formation of haploid embryoids of Larix decidua: early embryogenesis. Am J Bot 75:690–700von Aderkas P, Bonga JM (1993) Plants from haploid tissue of Larix decidua. Theor Appl Genet 87:225–228von Aderkas P, Klimaszewska K, Bonga JM (1990) Diploid and haploid embryogenesis in Plants from haploid tissue of Larix leptoletis, L. decidua, and their reciprocal hybrids. Can J For Res 20:9–14von Aderkas P, Pattanavibool R, Hristoforoglu K, Ma Y (2003) Embryogenesis and genetic stability in long term megagametophyte derived cultures of larch. Plant Cell Tiss Org Cult 75:27–34Wegrzyn JL, Lin BY, Zieve JJ, Dougherty WM, Martínez-García PJ, Koriabine M, Holtz-Morris A, deJong P, Crepeau M, Langley CH, Puiu D, Salzberg SL, Neale DB, Stevens KA (2013) Insights into the loblolly pine genome: characterization of BAC and fosmid sequences. PLoS One 8:e72439Xu Q, Chen LL, Ruan X, Chen D, Zhu A, Chen C, Bertrand D, Jiao WB, Hao BH, Lyon MP, Chen J, Gao S, Xing F, Lan H, Chang JW, Ge X, Lei Y, Hu Q, Miao Y, Wang L, Xiao S, Biswas MK, Zeng W, Guo F, Cao H, Yang X, Xu XW, Cheng YJ, Xu J, Liu JH, Luo OJ, Tang Z, Guo WW, Kuang H, Zhang HY, Roose ML, Nagarajan N, Deng XX, Ruan Y (2013) The draft genome of sweet orange (Citrus sinensis). Nat Genet 45:59–66Yu J (2009) The potential of ultrahigh throughput genomic technologies in crop improvement. Plant Genome 2: