Mildew Research Articles

Nueva variedad de “quinua” Chenopodium quinoa Wild. (Chenopodiaceae) para la sierra norte del Perú con características agronómicas y comerciales sobresalientes

In order to generate a new variety of quinoa for the northern highlands of Peru and contribute to the competitiveness of this andean grain, this research was carried out between 2013 and 2018. Phases of introduction and evaluation of germplasm, genetic improvement and advanced evaluation of promising materials were carried out. The first two phases carried out in INIA experimental fields and the third in farmer’s fields. Phenotypic characteristics, physiological maturity, mildew reaction and grain yield were evaluated. Also, there was opinion of farmers. Quantitative data was analyzed using ANVA and Duncan’s test. From the Genetic Compound A, introduced from the central highlands, the new variety of quinoa was generated, called INIA 437 Red of the North. It is accepted by the farmers of the research, It has white grain and semi-sweetness; purple in foliage and panicle; as well as outstanding characteristics of mildew tolerance and productivity, showing less damage to the disease and greater yield than the Witness, White of Junin variety; also It has greater profitability and productive stability than this; being suitable for cultivation in the study area.

Potensi Fungisida Perlakuan Benih terhadap Perenosclerospora sp. penyebab Penyakit Bulai Jagung

Jamur patogen Perenosclerospora sp. merupakan penyakit penting pada tanaman jagung. Dampak yang ditimbulkan dapat menimbulkan kerugian hingga 100%. Penelitian ini bertujuan untuk mengetahui pengaruh bahan aktif fungisida sebagai perlakuan benih dalam mengendalikan penyakit bulai (Perenosclerospora sp.) pada tanaman jagung. Penelitian dilaksanakan dengan diawali menanam tanaman jagung yang diinokulasi bulai sebagai tanaman spreader (sumber inokulum alami) dan pembatas antar perlakuan. Selanjutnya saat tanaman border sudah terinfeksi bulai baru ditanam benih perlakuan yang sudah dicampur dengan bahan aktif fungisida. Penelitian disusun dalam rancangan acak lengkap dengan delapan perlakuan dengan tiga ulangan. Perlakuan terdiri atas kontrol tanpa fungisida (P0), dimetomorf (P1), dimetomorf + piraklostrobin (P2), fenamidon (P3), fenamidon dan propamokarb hodroklorida (P4), metalaksil (P5), mefenoksam (P6), dan fluopikolid+propineb (P7). Hasil penelitian menunjukkan perlakuan kontrol lebih bagus dalam meningkatkan daya kecambah dibandingkan dengan menggunakan fungisida. Benih jagung yang diberikan perlakukan bahan aktif dimetomorf + piraklostrobin memiliki potensi yang paling tinggi dalam menekan keterjadian penyakit bulai pada jagung manis dan mampu meningkatkan pertumbuhan tinggi tanaman jagung yang dibandingkan perlakuan lainnya.

Breeding progress of disease resistance and impact of disease severity under natural infections in winter wheat variety trials

Key messageBreeding progress of resistance to fungal wheat diseases and impact of disease severity on yield reduction in long-term variety trials under natural infection were estimated by mixed linear regression models.This study aimed at quantifying breeding progress achieved in resistance breeding towards varieties with higher yield and lower susceptibility for 6 major diseases, as well as estimating decreasing yields and increasing disease susceptibility of varieties due to ageing effects during the period 1983–2019. A further aim was the prediction of disease-related yield reductions during 2005–2019 by mixed linear regression models using disease severity scores as covariates. For yield and all diseases, overall progress of the fully treated intensity (I2) was considerably higher than for the intensity without fungicides and growth regulators (I1). The disease severity level was considerably reduced during the study period for mildew (MLD), tan spot (DTR) and Septoria nodorum blotch (ear) (SNB) and to a lesser extent for brown (leaf) rust (BNR) and Septoria tritici blotch (STB), however, not for yellow/stripe rust (YLR). Ageing effects increased susceptibility of varieties strongly for BNR and MLD, but were comparatively weak for SNB and DTR. Considerable yield reductions under high disease severity were predicted for STB (−6.6%), BNR (−6.5%) and yellow rust (YLR, −5.8%), but lower reductions for the other diseases. The reduction for resistant vs. highly susceptible varieties under high severity conditions was about halved for BNR and YLR, providing evidence of resistance breeding progress. The empirical evidence on the functional relations between disease severity, variety susceptibility and yield reductions based on a large-scale multiple-disease field trial data set in German winter wheat is an important contribution to the ongoing discussion on fungicide use and its environmental impact.

Research Progress on Mildew Induced Corrosion of Al-alloy

Research Progress on Mildew Induced Corrosion of Al-alloy

Identification of new resistant sources against downy mildew disease from a selected set of cucumber germplasm and its wild relatives

This study was undertaken to identify new sources of resistance against downy mildew of cucumber caused by Pseudoperonospora cubensis [(Berk. and Cart.) Rostow]. Pot experiments were conducted with 16 accessions each of Cucumis sativus and C. hardwickii during the years 2017 and 2018 using 12 isolates of P. cubensis representing different agroclimatic zones of India. The accession, IC331627 from Dehradun, Uttarakhand showed plant disease index (PDI) ranging from 5.55-20.35 per cent with an average PDI of 11.56 and 11.87 per cent during the years, 2017 and 2018, respectively. Hence, IC331627 was identified to be resistant against the five isolates of P. cubesis (Pc12, Pc17, Pc19, Pc21 and Pc24) and moderately resistant against one isolate (Pc22). This resistant accession C. hardwickii (IC331627) could be utilized to develop mapping population to map genomic regions conferring the resistance to downy mildew in cucumber.

Identification of Podosphaera xanthii as the causal agent of powdery mildew disease affecting Echinacea purpurea in Korea

Identification of Podosphaera xanthii as the causal agent of powdery mildew disease affecting Echinacea purpurea in Korea

QTL Mapping and molecular markers of Powdery Mildew Resistance in Pumpkin (Cucurbita moschata)

QTL Mapping and molecular markers of Powdery Mildew Resistance in Pumpkin (Cucurbita moschata)

Determining the main agronomic traits of snake melon (Cucumis melo var. flexuosus L.) fruits as affected by genotypic differences

The variability affecting the main agronomic traits of 10 snake melon genotypes (Cucumis melo var. flexuosus L.) (three F1 hybrids, six breeding lines and the widely grown and consumed traditional cultivar Mornagui), grown under greenhouse conditions during 2014 and 2015 seasons, was examined and compared. Their resistance to powdery mildew was also checked. The main production-driving agronomic traits varied significantly (P<0.05) depending on the genotype. The major skin colour determined visually was different among the considered genotypes. The hybrids (H5 and H12) and the breeding lines (L1, L2, L5, L6 and L9) had dark green skin. The fruits of the hybrid H7 were dark and light green and the breeding line L4 has intense and dark green fruits whereas cv. Mornagui was characterized by medium light green fruits. Regarding fruit shape, the hybrids H7 and H5 produced straight fruits whereas the hybrid H12 and the breeding lines; L2, L4, L5, and L9 and the cv Mornagui had elongate fruits. However both breeding lines L1 and L6 were characterized by straight elongate fruits. The F1 hybrid H5 was the most productive (3.6 Kg/plant and ≈ 21 fruits/plant for total yield and number of fruit/plant respectively). These findings are useful for further breeding programs aiming to develop new powdery mildew resistant snake melon cultivars with satisfying agronomic traits.

The Research Progress of Preservatives against Mildew and Corrosion in Aquatic Products-A Review

The Research Progress of Preservatives against Mildew and Corrosion in Aquatic Products-A Review

Leveillula lactucae-serriolae on Lactuca serriola in Jordan

Jordan contributes significantly to the Near East plant biodiversity with numerous primitive forms and species of crops and their wild relatives. Prickly lettuce (Lactuca serriola) is a common species in Jordan, where it grows in various habitats. During a survey of wild Lactuca distribution in Jordan in August 2007, plants of L. serriola with natural infections of powdery mildew were observed at a site near Shobak (Ma’an Governorate). Lactuca serriola leaf samples with powdery mildew infections were collected from two plants and the pathogen was analyzed morphologically. Characteristics of the asexual and sexual forms were obtained. Sequence analyses of the rDNA ITS region and D1/D2 domains of the 28S rDNA were used to obtain phylogenetic data, and to reach taxonomic conclusions about these specimens. Molecular determination, performed by sequencing of the ITS region, proved its identity with the type material of Leveillula lactucae-serriolae. Sequencing of the 28S rDNA region provided the first verified GenBank record of Leveillula lactucae-serriolae deposited in this public nucleotide repository. This is the first taxonomically verified record of L. lactucae-serriolae on L. serriola growing wild in Jordan, and one of the first records of the fungus in the Near East.

Характеристика морфологічних ознак вегетативних органів дерев зникаючих сортів яблуні у Закарпатській області

На Закарпатті є всі умови для розвитку органічного садівництва. Для його впровадження можна використовувати місцеві сорти, які мають стійкість проти основних хвороб і адаптовані до місцевих ґрунтово-кліматичних умов. Аборигенні сорти зникають і замінюються новими, популярними сортами. Потрібно зберегти генофонд цих сортів для використання у селекції та, можливо, у технологіях органічного виробництва продукції. За вирощування сортів у плодорозсадниках необхідно добре вивчити сортові анатомо-морфологічні особливості саджанців, що дозволяє відрізнити їх між собою у разі відсутності плодів. Це і було метою наших досліджень. Виділені кращі сорти із високими продуктивними показниками без застосування пестицидного навантаження (Полованя, Краса Закарпаття, Соліварське, Батул, Дурнайка, Штетінське червоне маслянисте, Феркованя). Всі ці сорти є стійкими до основних хвороб, зокрема до парші та частково до борошнистої роси і раку. Морфологічні ознаки дерев описано відповідно до методики опису сортів. Протягом 2015-2018 років проведено літнє щеплення (окуліровка) та весняне щеплення живцем на підщепи: М.9, ММ.106, сіянці яблуні. Проведено оцінку сили росту саджанців на цих підщепах. Встановлено, що більшість з них: Дурнайка, Соліварське, Полованя, Феркованя володіють великою силою росту; Краса Закарпаття та Штетінське червоне — помірною; Батул — слабкою. Ці сорти мають перспективу використання в інтенсивних органічних садах за вирощування їх на відповідних підщепах. Всі сорти мають добру сумісність і приживлюваність з підщепами М.9 та ММ.106, які найчастіше використовуються в промислових насадженнях в Україні

Oomycetes Used in Arabidopsis Research.

Arabidopsis plants in their natural environment are susceptible to infection by oomycete pathogens, in particular to downy mildew and white rust diseases. These naturally occurring infectious agents have imposed evolutionary pressures on Arabidopsis populations and are therefore highly relevant for the study of host-pathogen co-evolution. In addition, the study of oomycete diseases, including infections caused by several Phytophthora species, has led to many scientific discoveries on Arabidopsis immunity and disease. Herein, we describe the major oomycete species used for experiments on Arabidopsis, and how these pathosystems have been used to provide significant insights into mechanistic and evolutionary aspects of plant-oomycete interactions. We also highlight understudied aspects of plant-oomycete interactions, as well as translational approaches, that can be productively addressed using the reference pathosystems described in this article.

Marker-assisted breeding for Downy mildew, Powderey mildew and Phylloxera resistance at FEM

Il programma di miglioramento genetico per le resistenze a stress biotici ha avuto inizio presso la Fondazione Edmund Mach (FEM) nel 2010. Inizialmente è stata condotta una caratterizzazione sia genotipica che fenotipica di materiali acquisiti da altri programmi di breeding e di materiale selvatico raccolto in New Jersey. Sia i genotipi conosciuti nei database internazionali che i genotipi sconosciuti, imparentati e non, sono stati impiegati come linee parentali nel processo di introgressione e di piramidazione di loci di interesse. Una volta pianificati e ottenuti gli incroci, la valutazione delle progenie è avvenuta seguendo un processo di Marker-Assisted Selection: dapprima è avvenuta la selezione fenotipica in serra in base al tipo di malattia e al numero di loci attesi per la medesima malattia; successivamente si è proceduto con lo screening molecolare in base ai loci specifici attesi nei parentali. Cinque sono i loci Run/Ren associati alla resistenza all'oidio presenti nel programma FEM; riguardo ai loci associati alla resistenza alla peronospora, quattro Rpv sono ben rappresentati nel piano di incroci. Ad oggi il 26% delle F1 è piramidizzato per quattro loci di resistenza.

Suspension Agaricus brasiliensis in the induction of phytoalexins and in the control of the grapevine downy mildew.

El objetivo del presente estudio fue verificar el efecto elicitor en la induccion de fitoalexina y control de la severidad del mildiu de la vid ( Plasmopara viticola ) en condiciones de campo de suspension micelial acuosa (SMA) de Agaricus brasilienis . Para inducir la fitoalexina en frijoles, soja, sorgo y severidade del mildiu, se utilizaron tratamientos que contienen a SMA de A. brasilensis lavada y sin lavar, asi como con y sin asociacion con aceite vegetal (OV), como tratamiento de control con agua y patrones con acibenzolar-S-metilo (ASM 0.005%) y Mezcla de Burdeos (1: 1: 1) ¬ En otro experimento, tambien para la determinacion de la induccion de fitoalexinas en soja y sorgo, se utilizaro las dosis de 0, 1, 5, 10, 15 y 20% da SMA de A. brasiliensis . Se verifico que el SMA de A. brasiliensis a 10%SMA indujo em 1000% y 56% la fitoalexina en frijoles y sorgo, respectivamente. Para la soya, se observo un aumento del 400% con 5% de SMA lavada de A. brasiliensis . Las dosis de esta suspension pueden inducir una induccion de 460% y 710% cuando se usa 20% de la SMA de cogumelo. En condiciones de campo no se verifico diferencias estadisticas entre los tratamientos aplicados a las vides. Por lo tanto, se puede decir que el SMA de A. brasiliensis presenta compuestos capaces de desencadenar un comportamiento inductor para respuestas de induccion de resistencia en plantas, pero no se observo ningun efecto directo sobre el patogeno evaluado.

Basil Tree, a New Host of Downy Mildew Pathogen Peronospora belbahrii

Basil (Ocimum spp.) is a popular herb grown worldwide. During the past fifteen years, a downy mildew pathogen has caused considerable damage to basil cultivations. In August 2017, downy mildew disease symptoms were found on Basil Tree (or long foot Basil Tree), which was developed by the grafting of two basil varieties and is a continuous harvest plant with a woody trunk. The present study reports the occurrence of downy mildew disease in basil Tree and identifies the causal pathogen, as Peronospora belbahrii.

Establishment and application of light initiated chemiluminescence assay of high mobility group box 1

Objective To establish a fast and quantitative light initiated chemiluminescent assay (LICA) method for high mobility group box1 (HMGB1) determination. Methods Two strains of paired HMGB1 monoclonal antibodies were used. One was used to coat receptor microspheres. The other was labeled with biotin first and then composed with chain mildew element of affinity donor microsphere to form LICA method for HMGB1. After optimizing the reaction system, the technical specifications of the method was evaluated. Serum HMGB1 levels of common pneumonia patients (CPP) and severe pneumonia patients (SPP) were measured and compared with that of health controls. Two-sample t test was used. Results The sensitivity of LICA was 0.1 μg/L, with linear measurement ranging from 0.1 to 1 000 μg/L. The precisions of intra- and inter-analysis were 1.74%-2.92% and 1.93%-3.73% respectively, both were lower than 5%. The recovery rate was 99.74% (range: 94.53%-106.37%). The correlation coefficient of LICA and enzyme-linked immunosorbent assay (ELISA) was 0.888 2. The LICA method had good specificity and no obvious cross reaction with HMGB2 and HMGB3. The serum HMGB1 level in CPP (n=35) and SPP (n=25) was significantly higher than that in health controls (n=35): (6.76±3.13), (19.69±9.04) vs (1.49±0.74) μg/L; t values: -5.447 and -5.186, both P<0.01. The HMGB1 levels between CPP and SPP were also significantly different (t=-3.500, P<0.01). Conclusions The established LICA method of HMGB1 has high sensitivity and specificity with reliable results. This method is also homogeneous, fast and cleaning-free, thus has a good prospect in clinical application. Key words: High mobility group proteins; Chemiluminescent measurements; Pneumonia

Podosphaera pannosa causes powdery mildew and rusty spot on peach fruits from Korea

Podosphaera pannosa causes powdery mildew and rusty spot on peach fruits from Korea

Relief-F筛选波段的小麦白粉病早期诊断研究

Relief-F筛选波段的小麦白粉病早期诊断研究

Study on weathering mechanism and protection method of masonry in humid environment

In order to better protect brick and stone cultural relics, this paper studies the present situation of brick and stone cultural relics in the open environment in humid areas with Xi'an city wall as an example. With various textures of brick and stone culture relics and complex and changeable natural environment, it determines that the protection methods of brick and stone cultural relics should be adapted to local conditions. For example, the protection methods should be different, as the outdoor environment is different from the indoor environment or in cases when there is big difference between a humid and warm environment and a dry and cold environment. This paper attempts to analyze and study the weathering status and disease mechanism of brick and stone cultural relics in humid areas. The study shows that humid environment is the most important factor causing damage to the weathering of brick and stone relics, and all kinds of diseases are generated or aggravated by the participation of water. A high efficiency and low toxicity compound antiseptic and mildew proof agent is made up by scientific proportion, whose bactericidal and bacteriostatic effect is verified with inhibition zone, the most commonly used method in biological control experiment. Moreover, the prevention and protection methods of biological weathering of brick and stone relics are put forward. It is concluded that the study of brick and stone cultural relics in humid environment can help to better carry out management and restoration of cultural relics.

FIRST REPORT OF POWDERY MILDEW CAUSED BY CYSTOTHECA LANESTRIS ON QUERCUS CRASSIPES IN MEXICO

Red oak or Tuchi (Quercus crassipes) is an ornamental endemic species of Mexico. On November 9, 2016, powdery mildew was observed on leaves of Tuchi in Santa Fe, Mexico City. The symptoms and signs included deformed leaves, irregular necrotic lesions on both sides of the leaf, premature leaf drop, chasmothecia and mycelium. A reference specimen (CMPH-ECO23S) was deposited in the Herbarium of the Colegio de Postgraduados. The fungus produced light brown to dark reddish chasmothecia immersed in the mycelium. Chasmothecia were grouped or dispersed, 99-111 µm in diameter, composed of polygonal peridial cells of 12-18 µm; with simple, sinuous, poorly developed, short, or almost absent mycelial appendages (4-4.5 µm wide) that were interlaced with the surrounding mycelium. The single ascus was hyaline, ellipsoid or ovoid to globose, sessile, 80-91 x 55-68 µm to 134 x 85 µm. The ascospores were hyaline, ellipsoid to ovoid, 25-32 x 18-22 µm. Conidiophores and conidia were not observed. Amplification of ITS was carried out using primers ITS4 and ITS5. The PCR product (459 bp) was sequenced and deposited in GenBank (accession No. MF170000). The obtained sequence showed 100% similarity to AF011289 from Q. agrifolia. No extype sequence of C. lanestris is in GenBank, but the type and this sequence are from Q. agrifolia in California, USA. Based on morphological and molecular characteristics, the fungus observed on Quercus crassipes was identified as Cystotheca lanestris (Braun and Cook, 2012). To our knowledge, this is the first report of this fungus causing powdery mildew of red oak in Mexico.