scholarly journals Metode inokulasi buatan untuk menguji infeksi Peronosclerospora maydis penyebab penyakit bulai tanaman jagung

Jurnal Agro ◽  
10.15575/4409 ◽  
2019 ◽  
Vol 6 (1) ◽  
pp. 77-85
Author(s):  
Satriyo Restu Adhi ◽  
Fitri Widiantini ◽  
Endah Yulia
Keyword(s):  
Downy Mildew ◽  
Artificial Inoculation ◽  
Resistance Testing ◽  
Infected Leaf ◽  
Suspension Spraying ◽  
Plant Materials ◽  
Inoculation Method ◽  
Resistant Varieties ◽  
Maize Plants ◽  
Leaf Insertion

Keberadaan penyakit bulai akibat Peronosclerospora maydis pada tanaman jagung mampu menyebabkan kehilangan hasil hingga 100%. Pengendalian penyakit bulai dengan menggunakan varietas tahan dinilai cukup efektif. Di dalam pengembangan varietas tahan, seleksi ketahanan calon varietas baru harus dilakukan dan hal ini akan melibatkan inokulasi buatan. Tujuan dari penelitian ini adalah untuk mendapatkan metode inokulasi buatan Peronosclerospora maydis yang efektif pada tanaman jagung pada skala rumah kaca. Penelitian dilaksanakan di Laboratorium Bioteknologi Proteksi Tanaman dan rumah kaca Departemen Hama dan Penyakit Tumbuhan, Fakultas Pertanian, Universitas Padjadjaran pada bulan Oktober hingga Desember 2018. Bahan tanaman yang diinokulasikan berupa kecambah dan bibit tanaman jagung. Metode inokulasi buatan yang diujikan terdiri atas: (1) Sisip daun terinfeksi bulai pada kecambah (SD), (2) Semprot suspensi konidia pada kecambah (SI), (3) Sisip daun bergejala bulai + semprot suspensi konidia pada kecambah (SS), (4) Rendam kecambah pada suspensi konidia (RS), (5) Semprot suspensi konidia pada bibit (SB), dan dua perlakuan tanpa inokulasi (kontrol). Dari hasil percobaan metode sisip daun (SD) menyebabkan 83,3% tanaman jagung terinfeksi bulai dan dinilai sebagai metode inokulasi buatan yang efisien.Kata kunci: bulai, jagung, inokulasi buatan, Peronosclerospora maydis. ABSTRACTDowny mildew disease caused by Peronosclerospora maydis in maize plants can cause yield loss up to 100%. Disease management of downy mildew by using resistant varieties is considered quite effective. One of the steps to develop resistant varieties is resistance testing of the new variety candidates that involve artificial inoculation. The purpose of this study was to obtain an effective artificial inoculation method of Peronosclerospora maydis  in maize plants in greenhouse. The research was conducted at the Laboratory of Biotechnology of Plant Protection and Glasshouse Department of Plant Pests and Diseases, Agriculture Faculty, Universitas Padjadjaran from October to December 2018. The plant materials used for inoculation were sprout and seedling of maize plant. The artificial inoculation methods tested were (1) infected leaf insertion among the sprouts (SD), (2) conidia suspension spraying on the sprouts (SI), (3) infected leaf insertion + conidia suspension spraying on the sprouts (SS), (4) sprout soaking in conidia suspension (RS), (5) conidia suspension spraying on the seedling (SB), and two treatments without inoculation (controls). The result showed that the insertion of infected leaves among the sprouts (SD) treatment resulted in 83.3% of infected maize plants by the downy mildew and was considered as the most efficient inoculation method. 

Artificial Inoculation Method of Pokkah Boeng Disease of Sugarcane and Screening of Resistant Germplasm Resources in Subtropical China

Sugar Tech ◽  
2016 ◽  
Vol 19 (3) ◽  
pp. 283-292 ◽  
Author(s):  
Ze-Ping Wang ◽  
Hai-Jun Sun ◽  
Qiang Guo ◽  
Shi-Qiang Xu ◽  
Ji-Hua Wang ◽  
...  
Keyword(s):  
Artificial Inoculation ◽  
Germplasm Resources ◽  
Subtropical China ◽  
Inoculation Method ◽  
Pokkah Boeng

scholarly journals PENGARUH STOMATA DAN KLOROFIL PADA KETAHANAN BEBERAPA VARIETAS JAGUNG TERHADAP PENYAKIT BULAI (STOMATA AND CHLOROPHYLL’S INFLUENCE ON THE RESISTANCE OF SEVERAL MAIZE VARIETIES AGAINST DOWNY MILDEW)

2017 ◽  
Vol 20 (2) ◽  
pp. 89
Author(s):  
Christine Agustamia ◽  
Ani Widiastuti ◽  
Christanti Sumardiyono
Keyword(s):  
Chlorophyll Content ◽  
Downy Mildew ◽  
Sweet Corn ◽  
Stomatal Density ◽  
Disease Incidence ◽  
Dry Weight ◽  
Resistant Varieties ◽  
Maize Varieties ◽  
Weight Data ◽  
Range Test

Resistant varieties are more advisable for controlling maize downy mildew compared with fungicides which is not effective and not environmentally friendly. This study is aimed to determine resistance of some varieties of maize against downy mildew. The maize varieties used were BS 0114, BS 0214, BS 0314, PAC 105, Sweet Corn and BISI 2. The parameters measured were disease incidence and intensity, chlorophyll content of leaves, stomatal density and plants dry weight. Data were analyzed by using analysis of variance (ANOVA) and Duncan's Multiple Range Test (DMRT). The results indicated that PAC 105, BS 0214 and BS 0314 were resistant varieties, while BS 0114, Sweet Corn and BISI 2 were susceptible. PAC 105 variety has the lowest stomatal density (65.353/mm2), and Sweet Corn variety has the highest stomatal density (110.79/mm2). Stomatal density was positively correlated with the disease intensity. Higher disease intensity has lower chlorophyll content compared with the lower intensity. PAC 105 variety has the highest chlorophyll content and plant dry weight, while Sweet Corn variety has the lowest chlorophyll content and plant dry weight. Penggunaan varietas tahan bulai lebih dianjurkan digunakan dalam pengendalian penyakit bulai pada jagung dibandingkan dengan penggunaan fungisida karena tidak efektif dan tidak ramah lingkungan. Penelitian ini bertujuan untuk mengetahui ketahanan beberapa varietas jagung terhadap penyakit bulai. Varietas yang digunakan meliputi BS 0114, BS 0214, BS 0314, PAC 105, jagung manis, dan BISI 2. Parameter yang diamati adalah insidensi dan intensitas penyakit, kandungan klorofil setelah inokulasi, kerapatan stomata dan berat kering tanaman. Data yang diperoleh diuji dengan analisis varians (ANOVA) dan uji lanjut dengan Duncan’s Multiple Range Test (DMRT). Hasil penelitian rumah kaca menunjukkan bahwa varietas PAC 105, BS 0214 dan BS 0314 merupakan varietas tahan, sedangkan varietas BS 0114, jagung manis dan BISI 2 merupakan varietas yang rentan. Varietas tahan PAC 105 memiliki kerapatan stomata paling rendah yaitu 65,353/mm2, dan kerapatan stomata paling tinggi dimiliki oleh varietas rentan yaitu jagung manis dengan kerapatan 110,79/mm2. Kerapatan stomata berkorelasi positif dengan intensitas penyakit dengan koefisien korelasi (r) sebesar 0,72526. Semakin rendah intensitas penyakit bulai kandungan klorofil dan berat kering yang semakin tinggi. Varietas PAC 105 yang mempunyai intensitas penyakit paling rendah , mempunyai kandungan klorofil dan berat kering tertinggi, sedangkan varietas jagung manis mempunyai kandungan klorofil dan berat kering terendah.

scholarly journals Effect of Detergent on the Quantification of Grapevine Downy Mildew Sporangia from Leaf Discs

HortScience ◽  
2015 ◽  
Vol 50 (5) ◽  
pp. 656-660 ◽  
Author(s):  
Atsushi Kono ◽  
Akihiko Sato ◽  
Bruce Reisch ◽  
Lance Cadle-Davidson
Keyword(s):  
Downy Mildew ◽  
Leaf Disc ◽  
Plasmopara Viticola ◽  
Inhibitory Effect ◽  
Tween 20 ◽  
Infected Leaf ◽  
Grapevine Downy Mildew ◽  
Visual Rating ◽  
Leaf Discs ◽  
Highly Correlated

Grapevine downy mildew (DM), caused by the oomycete Plasmopara viticola (Berk. & Curt.) Berlese & de Toni, is a major disease, especially in humid viticultural areas. Development of resistant cultivars is an important objective for grapevine breeding. To establish a reliable and inexpensive quantitative method to aid in breeding for DM resistance, we improved the method for counting the number of sporangia on leaf discs, and developed a method for counting the number of sporangia in solution. To prevent the loss of DM sporangia from adhesion onto plastic ware, we found as little as 0.01% Tween 20 was effective. On the other hand, this detergent was shown to have a severe inhibitory effect upon DM infection of leaves. We developed a sporangia counting method using dried droplets of DM suspensions, and the method was highly correlated with counting by hemacytometer (R2 > 0.96). The nonparametric Spearman’s rank correlations between visual rating and the number of the sporangia were as high as ρ = 0.82 to 0.91, suggesting that evaluation by the visual rating could provide a good estimate of the sporangia numbers on leaf discs. We established a high-throughput and inexpensive method with acceptable accuracy for DM resistance evaluation based on a leaf disc assay, and our results suggested that visual ratings of infected leaf discs provide a good estimate of sporangia numbers.

Peronospora dianthicola. [Descriptions of Fungi and Bacteria].

1983 ◽  
Author(s):  
S. M. Francis
Keyword(s):  
Downy Mildew ◽  
Geographical Distribution ◽  
Disease Transmission ◽  
Dianthus Caryophyllus ◽  
Weather Conditions ◽  
Axillary Buds ◽  
Pseudoperonospora Humuli ◽  
Resistant Varieties ◽  
Weed Hosts ◽  
Pale Green

Abstract A description is provided for Peronospora dianthicola. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOST: Dianthus caryophyllus. DISEASE: Downy mildew of carnation. Early symptoms are seen on the leaves which have pale green to yellowish transverse bands and may bend at these lesions. Infected plants are stunted and become withered. Infection of the growing point may result in the development of axillary buds giving the plants a bushy appearance. Barthelet describes the shoots which can develop in some resistant varieties as resembling the basal spikes of Pseudoperonospora humuli on hops, i.e., shoots with smaller leaves, thickened stem and shortened internodes. GEOGRAPHICAL DISTRIBUTION: Europe (Britain*, Denmark, France, Greece, Turkey); N. America (California, USA); S. America (Colombia). *no herbarium material, but recorded by F.A. Mason, The Naturalist no. 848: 270, 1927; on leaves of carnation under glass, Duncombe Park, Helmsley, Yorks. (Sept. 1920). TRANSMISSION: Oospores, which are formed abundantly in the tissues of diseased plants, are thought to be important in disease transmission. A small amount of infection is often seen on the plants in the autumn and these foci can allow the pathogen to overwinter until more favourable weather conditions permit the spread of the disease the following spring. Possible weed hosts for the pathogen such as Cerastium and Stellaria, growing in the vicinity, were examined and found to be infected with a different species of Peronospora belonging to the P. alsinearum group (33, 230).

scholarly journals Transfer of Downy Mildew Resistance from Wild Basil (Ocimum americanum) to Sweet Basil (O. basilicum)

2018 ◽  
Vol 108 (1) ◽  
pp. 114-123 ◽  
Author(s):  
Yariv Ben-Naim ◽  
Lidan Falach ◽  
Yigal Cohen
Keyword(s):  
Downy Mildew ◽  
Dominant Gene ◽  
Susceptible Parent ◽  
Backcross Generation ◽  
Sweet Basil ◽  
Resistant Varieties ◽  
Homeologous Chromosomes ◽  
Tetraploid Parent ◽  
Dominant Genes

Sweet basil (Ocimum basilicum) is susceptible to downy mildew caused by the oomycete foliar pathogen Peronospora belbahrii. No resistant varieties of sweet basil are commercially available. Here, we report on the transfer of resistance gene Pb1 from the highly resistant tetraploid wild basil O. americanum var. americanum (PI 500945, 2n = 4x = 48) to the tetraploid susceptible O. basilicum ‘Sweet basil’ (2n = 4x = 48). F1 progeny plants derived from the interspecific hybridization PI 500945 × Sweet basil were resistant, indicating that the gene controlling resistance (Pb1) is dominant, but sterile due to the genetic distance between the parents. Despite their sterility, F1 plants were pollinated with the susceptible parent and 115 first backcross generation to the susceptible parent (BCs1) embryos were rescued in vitro. The emerging BCs1 plants segregated, upon inoculation, 5:1 resistant/susceptible, suggesting that resistance in F1 was controlled by a pair of dominant genes (Pb1A and Pb1A’). Thirty-one partially fertile BCs1 plants were self-pollinated to obtain BCs1-F2 or were backcrossed to Sweet basil to obtain the second backcross generation to the susceptible parent (BCs2). In total, 1 BCs1-F2 and 22 BCs2 progenies were obtained. The BCs1-F2 progeny segregated 35:1 resistant/susceptible, as expected from a tetraploid parent with two dominant resistant genes. The 22 BCs2 progenies segregated 1:1 resistant/susceptible (for a BCs1 parent that carried one dominant gene for resistance) or 5:1 (for a BCs1 parent that carried two dominant genes for resistance) at a ratio of 4:1. The data suggest that a pair of dominant genes (Pb1A and Pb1A’) residing on a two homeologous chromosomes is responsible for resistance of PI 500945 against P. belbahrii.

Optically-assessed preformed flavonoids and susceptibility of grapevine to Plasmopara viticola under different light regimes

2008 ◽  
Vol 35 (1) ◽  
pp. 77 ◽  
Author(s):  
Giovanni Agati ◽  
Zoran G. Cerovic ◽  
Anna Dalla Marta ◽  
Valentina Di Stefano ◽  
Patrizia Pinelli ◽  
...  
Keyword(s):  
Downy Mildew ◽  
Large Scale ◽  
Plasmopara Viticola ◽  
Vitis Vinifera L ◽  
Infected Leaf ◽  
Light Regimes ◽  
Polyphenolic Content ◽  
Non Destructive ◽  
Large Scale Screening

The role of flavonoids in the response of plants to Plasmopara viticola, the phytopathogen agent of downy mildew, was studied in the Vitis vinifera L. cultivar Sangiovese. Grapevines in the vineyard were exposed to two light regimes, 100% and 35% of full sunlight in order to induce differences in total leaf polyphenolic content. Epidermal leaf phenolic compounds were assessed optically, using the Dualex chlorophyll fluorescence-based portable leaf-clip. Dualex data were calibrated by means of HPLC analysis of extracts from the same measured leaves. Good correlations were obtained with total flavonoid contents, which consist mainly of quercetin 3-O-glucuronide. From the Dualex non-destructive measurements, we showed that full-sun exposed leaves contained 75% more flavonoids than shaded leaves. Inoculation of leaves with P. viticola sporangia resulted in a significantly lower infected leaf area in sun-lit leaves compared with shaded ones, as seen from subsequent analysis of the downy mildew severity. These results indicated an inverse relationship between preformed flavonoids and the susceptibility of grapevines to downy mildew. The rapid optical method for the non-destructive assessment of flavonoids presented here could be useful for large scale screening and predicting V. vinifera susceptibility to P. viticola.

scholarly journals Analysis of Downy Mildew Infection of Field Pea Varieties Using the Logistic Model

2012 ◽  
Vol 52 (2) ◽  
pp. 240-246 ◽  
Author(s):  
Ewa Bakinowska ◽  
Wiesław Pilarczyk ◽  
Agnieszka Osiecka ◽  
Kazimierz Wiatr
Keyword(s):  
Downy Mildew ◽  
Logistic Model ◽  
Field Trials ◽  
Field Pea ◽  
Model Parameters ◽  
Scoring Method ◽  
Multinomial Data ◽  
Time Period ◽  
Resistant Varieties ◽  
Evaluation Of Data

Analysis of Downy Mildew Infection of Field Pea Varieties Using the Logistic ModelThe logistic model is commonly used for analysis of discrete, multinomial data. Such a model was used for the statistical evaluation of data concerning infection of field pea varieties by downy mildew, in two series of field trials. Each series consisted of experiments performed in locations spread over the whole of Poland in the time period from 2002 to 2005. Varieties cultivated on light soils were compared in the first series, and varieties cultivated on rich soils in the second. The most resistant varieties were identified (Sokolik - light soils, Terno - rich soils) and significant differences among varieties were detected. Estimators of model parameters were found using the Fisher scoring method implemented inlogistic glmprocedure of the SAS system.

scholarly journals Inheritance of resistance to cotton blue disease

2008 ◽  
Vol 43 (5) ◽  
pp. 661-665 ◽  
Author(s):  
Osmério Pupim Junior ◽  
Ivan Schuster ◽  
Ronald Barth Pinto ◽  
Ely Pires ◽  
Jean-Louis Belot ◽  
...  
Keyword(s):  
Disease Resistance ◽  
Dominant Gene ◽  
Artificial Inoculation ◽  
Inheritance Of Resistance ◽  
Greenhouse Test ◽  
Resistant Varieties ◽  
Cotton Blue ◽  
Cotton Plants ◽  
Cotton Blue Disease

The objective of this work was to determine the inheritance of cotton blue disease resistance by cotton plants. Populations derived from the CD 401 and Delta Opal resistant varieties were evaluated, through a greenhouse test with artificial inoculation by viruliferous aphids. Cotton blue disease resistance is conditioned by one dominant gene, both in CD 401 and Delta Opal varieties.

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