scholarly journals Resistance Response of Maize Germplasm to Downy Mildew [Peronosclerospora philipinensis]

2018 ◽  
Vol 24 (1) ◽  
pp. 43
Author(s):  
Syahrir Pakki ◽  
Mappaganggang Mappaganggang

<p>Two experiments to study responses of resistance of maize germplasm to downy mildew (Peronosclerospora philipinensis) have been conducted. Both experiments were arranged in randomized block design with two replication. The treatments in each experiment (2014 and 2016) were 70 maize accessions. The accessions were planted in planting distant of 75 cm × 20 cm, in 5 m rows, resulting in 20 plants per row. In every 10 rows, two check varieties were planted, i.e. one susceptible and one resistant variety. Ten days prior to planting, the soil was fertilized with mixed fertilizers consisted of urea, ZA, SP36, and KCl at a dose of 100, 100, 100, and 100 kg/ha, respectively. Fertilization II and III was given at 30 days after planting, and 45 days after planting with a dose of 100 kg urea/ha. As a source of inoculum downy mildew, around the repeated plot was planted with varieties Anoman variety (susceptible variety) that was inoculated with a suspension of downy mildew pathogen. Observation was conducted at 25, 35, and 55 days after planting, with the standard score of resistant to downy mildew, followed: 0–10% = resistant, 11–25% = moderately resistant, 26–50% = moderately susceptible, &gt;50% = susceptible. The result of the experiments showed that there were 5 accessions resistant to downy mildew (P. philipinensis), i.e. CML 440×MR4-9-30-3, 664, 60, 572, and 554 with the intensity of downy mildew infection ranged from 5 to 10%. Twelve other accessions were classified as moderately resistant, i.e. CML 440×MR4-9-98-2, 440×MR4-9-98-4 CML, CML 440×MR4-9-124-1, 66, 71, 319, 108, 73, 48, 105, 554, and 682 with intensity of infection ranged from 13 to 25%. At the same experiments, the average intensity of downy mildew infection on susceptible check varieties reached 100 percent.</p>

2020 ◽  
Vol 13 (3) ◽  
pp. 81
Author(s):  
I G.A.A. INDRAYANI ◽  
SIWI SUMARTINI ◽  
B. HELIYANTO B. HELIYANTO

ABSTRAK<br />Amrasca biguttula (Ishida) adalah serangga hama pengisap daun<br />yang sangat potensial menurunkan produktivitas kapas. Pengendaliannya<br />secara kimiawi menimbulkan banyak masalah lingkungan, seperti<br />pencemaran dan peningkatan resistensi hama terhadap insektisida kimia<br />sintetis. Salah satu solusi dalam masalah tersebut adalah penggunaan<br />varietas tahan (resisten) yang juga merupakan bagian dari pengendalian<br />hama terpadu (PHT) pada kapas. Penelitian ketahanan beberapa aksesi<br />kapas terhadap A. biguttula (Ishida) dilakukan di Kebun Percobaan Balai<br />Penelitian Tanaman Tembakau dan Serat di Asembagus, Situbondo, mulai<br />Januari hingga Desember 2006. Tujuannya adalah untuk mengetahui<br />ketahanan beberapa aksesi kapas terhadap serangan hama pengisap daun,<br />A. biguttula. Sebagai perlakuan adalah 30 aksesi kapas yang ditanam<br />dalam plot berukuran 10 m x 3 m, dengan jarak tanam 100 cm x 25 cm,<br />satu tanaman per lobang. Setiap aksesi disusun dalam rancangan acak<br />kelompok dengan tiga kali ulangan. Parameter yang diamati adalah jumlah<br />nimfa A. biguttula per daun, jumlah bulu daun per cm 2 luas daun, dan<br />posisi bulu terhadap lamina (tegak/rebah), serta skor kerusakan tanaman.<br />Hasil penelitian menunjukkan bahwa setiap aksesi kapas berpotensi<br />terserang A. biguttula, meskipun tingkat populasi hama ini tidak<br />menunjukkan perbedaan nyata antar aksesi. Terjadi korelasi negatif (R 2 =<br />0,2425) antara jumlah bulu daun dan populasi nimfa A. biguttula dan<br />antara jumlah bulu daun dan skor kerusakan tanaman (R 2 = 0,2027).<br />Berdasarkan jumlah bulu daun, aksesi kapas yang termasuk kategori<br />sedikit berbulu dengan kriteria ketahanan sedikit tahan adalah: AC 134,<br />Stoneville 7, Fai Nai, SHR, CRDI-1, Kanesia 5, Kanesia 8, dan Kanesia 9.<br />Sedangkan aksesi lainnya termasuk kategori tidak berbulu dan peka<br />terhadap serangan A. biguttula.<br />Kata kunci : Kapas, Gossypium hirsutum, aksesi, hama, Amrasca<br />biguttula (Ishida), toleran, peka, kerusakan, Jawa Timur<br />ABSTRACT<br />Resistance of several cotton accessions to sucking insect<br />pest, Amrasca biguttula (Ishida)<br />Amrasca biguttula (Ishida) is a sucking insect pest which potentially<br />reduces cotton productivity. Its chemical control often cause environ-<br />mental problems mainly air pollution and increase of pest resistance to<br />certain chemical insecticides. One solution can be used to solve these<br />problems is by using resistant variety that is also an integral part of the<br />integrated pest management (IPM). Study on the resistance of several<br />cotton accessions to sucking insect pest, Amrasca biguttula (Ishida) was<br />conducted at the Experimental Station of the Indonesian Tobacco and<br />Fiber Crops Research Institute (IToFCRI) in Asembagus, Situbondo, East<br />Java, from January to December 2006. The objective of the study was to<br />find out the resistance of cotton accessions to sucking insect pest. Thirty<br />accessions of cotton were used as treatment and were planted in plots 10 m<br />x 3 m with plant spacing 100 cm x 25 cm, one plant per hole. Each<br />accession was arranged in a randomized block design with three<br />replications. Parameters observed were number of nymph of A. biguttula,<br />number of leaf hair, leaf hairs position (erect or lie down), and score of<br />damage. The result showed that every accession of cotton can be attacked<br />by A. biguttula although the insect population was not significantly<br />different among accessions. There is negative correlation (R 2 = 0.2425)<br />between number of leaf hair and population of A. biguttula and between<br />number of leaf hair and score of plant damage (R 2 = 0.2027). Accessions<br />that categorized as lightly hairy and moderately resistant to A. biguttula<br />were AC 134, Stoneville 7, Fai Nai, SHR, CRDI-1, Kanesia 5, Kanesia 8,<br />and Kanesia 9, while the others were categorized as glabrous and<br />susceptible to the sucking pest.<br />Key words: Cotton, Gossypium hirsutum, accession, insect pest, Amrasca<br />biguttula (Ishida), tolerant, sensitive, damage, East Jav


2018 ◽  
Vol 10 (1) ◽  
pp. 98-101
Author(s):  
T. A. Wani ◽  
G. N. Bhat ◽  
Mushtaq Ahmad ◽  
A. Anwar ◽  
Gul Zaffar

: A study was conducted during Kharif 2012 and 2013 at Sher-e-Kashmir University of Agricultural Sciences and Technology of Kashmir, Shalimar Campus Srinagar with the objective of screening sixty maize genotypes against Turcicum leaf blight caused by Exserohilum turcicum (Pass.) Leonard and Suggs. Field experiment was laid out in a randomized block design with three replications. In order to ensure establishment of infection, artificial inoculation of E. turcicum on test genotypes was made twice at 30 and 40 days after sowing with two different methods of inoculation (spraying on foliage of maize with spore suspension of pathogen @ 5x104 spores/ml at 30 DAS and by whorl drop inoculation of pathogen multiplies on sorghum grains at 40 DAS). Disease severity on test entries was scored at silk drying stage and studies revealed that two inbred lines, viz., NAI-112 and NAI-147, and one hybrid, viz., HQPM-1 were found resistant with pooled disease intensity of 4.12 per cent, 4.04 per cent and 4.38 per cent, respectively. Four inbred lines, viz., KDM 381 A, KDM 918 A, NAI-152 and NAI-167 were found susceptible with pooled disease intensity of 52.82 per cent, 51.02 per cent, 58.58 per cent and 61.33 per cent, respectively. The remaining genotypes were moderately resistant to moderately susceptible.


Agrikultura ◽  
2018 ◽  
Vol 29 (2) ◽  
pp. 100
Author(s):  
Helmi Kurniawan ◽  
Ineu Sulastrini ◽  
Tarkus Suganda

ABSTRACTResistance Test of Potato Clones Derived from Crossing of Atlantic x Repita to Late Blight (Phytophthora infestans)Late blight, incited by Phytophthora infestans is the most destructive disease of potato. The management that is effective and environmentally-friendly is the use of resistant variety. The objective of this study was to test the resistance of the six potato clones (AR 04, AR 05, AR 06, AR 07, AR 08 and AR 09) derived from crossing var. Atlantic x var. Repita to late blight caused by P. infestans. Var. Atlantic, Repita and Granola were used as susceptible, resistant and susceptible but the most-grown variety, respectively. Field test was located in Ciwidey, one of the potato growing center where late blight is endemic since potatoes are continuously grown. The treatments were arranged in a randomized block design with 3 replicates. The result showed that clones AR 07 and AR 08 were more resistant than the other potato clones, but it still below the resistance level var. Repita. However, based on statistical test on the diseases development (AUDPC), clone AR 08 could be categorized as resistant, equal with of the resistance level of var. Repita.Keywords: Potato clones, Rsistance, P. infestansABSTRAKPenyakit hawar daun yang disebabkan Phytopthora infestans merupakan penyakit utama pada tanaman kentang. Pengendalian yang efektif dan ramah lingkungan adalah dengan penanaman varietas tahan. Penelitian ini bertujuan untuk menguji ketahanan 6 klon kentang (AR 4, AR5, AR6, AR7, AR 8, dan AR9) yang merupakan hasil persilangan antara var. Atlantic (produksi tinggi tetapi rentan) dengan var. Repita, sebagai tetua tahan terhadap penyakit hawar daun yang disebabkan oleh P. infestans. Varietas Atlantic, Repita dan Granola digunakan sebagai pembanding. Pengujian ketahanan dilakukan di Ciwidey, yang merupakan salah satu sentra produksi kentang di Jawa Barat dan endemik penyakit hawar daun. Perlakuan ditata menggunakan Rancangan Acak Kelompok dengan 3 ulangan. Hasil penelitian menunjukkan bahwa klon AR 07 dan Klon AR 08 memiliki ketahanan yang lebih baik dibanding klon-klon kentang lainnya, namun tingkat ketahanannya masih di bawah cv Repita. Namun, berdasarkan uji statistik terhadap nilai perkembangan penyakit (AUDPC) klon AR 08 dapat dikategorikan tahan, sama dengan derajat tahan var. Repita.Kata Kunci: Klon kentang, Ketahanan, P. infestans


2019 ◽  
Vol 49 ◽  
Author(s):  
Bruno Zuntini ◽  
Rita de Cassia Félix Alvarez ◽  
Gustavo de Faria Theodoro ◽  
Alan Mario Zuffo

ABSTRACT Fungicides used to control the Asian soybean rust are composed almost entirely of mixtures involving the systemic (triazoles) and meso-systemic (strobilurins) modes of action. However, to control the soybean downy mildew, only protective fungicides are available. The present study aimed to evaluate the effectiveness of fungicides with different modes of action in the control of downy mildew and Asian soybean rust. A field experiment was carried out in a randomized block design, with seven treatments [negative control; difenoconazole at V7 + (azoxystrobin + cyproconazole) at R2 and R5.1; (tebuconazole + carbendazim) at V7 + (azoxystrobin + tebuconazole) at R2 and R5.1; carbendazim and mancozeb at V7 + (azoxystrobin + tebuconazole) at R2 and R5.1; (tebuconazole + carbendazim) at V7 + mancozeb in V7 + (azoxystrobin + tebuconazole) at R2 and R5.1; (tebuconazole + carbendazim) at V7 + (azoxystrobin + tebuconazole) at R2 and R5.1 + mancozeb at R2 and R5.1; (tebuconazole + carbendazim) at V7 + azoxystrobin + tebuconazole at R2 and R5.1 + mancozeb at R2 and R5.1 + carbendazim at R5.1] and four replicates. The following variables were evaluated: disease severity based on diagrammatic scales, phytotoxicity, product effectiveness, defoliation, number of pods per plant, number of seeds per pod, 1,000-seed weight and yield. The treatments with mancozeb addition showed to be more efficient in reducing the severity of mildew and Asian soybean rust and defoliation, providing increased seed yields for the crop. For the soybean downy mildew, the treatments with addition of mancozeb to benzimidazole, strobilurins and triazoles were more efficient in reducing the severity and for the control.


2016 ◽  
Vol 2 ◽  
pp. 22-26 ◽  
Author(s):  
Ram Devi Timila ◽  
Shrinkhala Manandhar

Bacterial wilt caused by Ralstonia solanacearum E.F. Smith is one of the destructive diseases of solanaceous vegetables specially tomato (Lycopersicon esculentum L.) and eggplant (Solanum melongena L.). Experiments were conducted to determine biovar types existing among the strains or isolates of Nepal and variation in virulence in some vegetables belonging to solanaceae family. A total of 39 isolates infecting tomato, eggplant, chilli and potato collected from different parts of Nepal were analyzed for biovar types on the basis of 3 disaccharides and 3 hexose alcohols oxidation test.  Experiments were conducted to determine variation in virulence or aggressiveness of some of the  isolates under  screen house conditions using three host differentials such as Pusa Ruby (susceptible), Bishesh (moderately resistant) and Srijana (resistant) tomato cultivars. Of the 39 isolates, 23 were biovar III, three biovar II, three biovar IV, and one was biovar I. Nine isolates could not be differentiated into any of the five biovars. For breeding and epidemiological purposes it is very important to analyze the variability of aggressiveness. A total of 5 isolates collected from different places were included in the test. Isolates from Bhaktapur was found the most virulent causing wilt in the variety Bishesh (moderately resistant). Other isolates had the negative impact with zero wilt on the differentials used. Isolates from Jungekhola of Dhading district did not induce wilt even on susceptible variety (Pusa Ruby), but exhibited only senescence reaction. The result indicated that there is some slight variation among the isolates tested. Some effective management tactics might be needed in those locations where highly aggressive or virulent strain of bacterial wilt is prevalent, because resistant variety may not be stable in such locations.


2020 ◽  
Vol 6 (2) ◽  
pp. 33
Author(s):  
GEMBONG DALMADIYO ◽  
MOCH. AMIR KARTAMIDJAJA

<p><strong>The effect of tobacco curl disease on the yield and quality of eight Virginia tobacco varieties</strong></p><p>Tobacco leaf curl disease is one of the important diseases on Virginia tobacco which especially occurs in dry condition. The use of resistant varieties is one of the most effective way to control the disease. This experiment was lo evaluate the effect of tobacco curl disease on tobacco varieties (DB 101, Coker 319, Coker 176, Coker 48, Coker 86, and Coker 371 Gold) and two promising lines (T.45/T.65 and T.45/T.69). The experiment was conducted in Pekuwon, Sumberrejo, Bojonegoro from April to October 1997. The experiment was arranged in randomized block design with three replications. The tobacco seedlings wee transplanted in 0.9 m x 0.6 m spacing and 9.0 m x 9.0 m plot size. The fertilizer dosage applied are 300 kg ZA + 108 kg SP-36 + 156 kg ZK per ha The parameters observed including percentage of diseased plant, productive leaves, as well as the yield and quality of leaves. The esults showed that Coker 371 Gold variety showed the lowest disease percentage (6.89%), decrease in productive leaves was high (71.86%), Whereas the two promising lines, were T.45/T.6S and T.45/T.69 showed that the percentage of diseased plants wee not significantly different compared with DB 101, Coker 319, and Coker 48, but the decrease in productive leaves was lower. The yield of these promising lines were 10.12-10.30 kg/81 m!, grade indexes 86.04-87.27, and crop indexes are 88.31-88.63. Coker 176 was the most susceptible variety. The percentage of diseased plant, flue- cured yield, grade index, and crop index on Coker 176 wee 42.67%, 7.77 kg/81 m!, 86.09, and 66.89, respectively.</p>


Author(s):  
Ayda Krisnawati ◽  
ANDY SOEGIANTO ◽  
BUDI WALUYO ◽  
KUSWANTO

Abstract. Krisnawati A, Soegianto A, Waluyo B, Kuswanto. 2019. Selection of F6 soybean population for pod shattering resistance. Biodiversitas 20: 3340-3346. Pod shattering is one of the major soybean constraints in Indonesia. This research aimed to evaluate the resistance of soybean F6 population to pod shattering and characterize the selected lines for their agronomic performances. The materials used were 147 F6 lines derived from six crossing combinations. The check varieties consisted of Dega 1, Detap 1, and Anjasmoro. The experiment was arranged in a randomized block design with two replications. At R8 stage, thirty pods were randomly detached from five sample plants of each line to be used for evaluation of pod shattering resistance using an oven-dry method. The variability of pod shattering was showed after the treatment of 60°C oven temperature. The shattering resistance of 147 F6 lines was classified into 52 highly resistant, 49 resistant, two moderately resistant, ten susceptible, and 34 highly susceptible lines. The pod-shattering resistant lines could be used for further improvement in the breeding program. Anjasmoro variety was effective to be used as gene source for shattering resistant. Simultaneous selection based on yield (30% selection intensity) and shattering resistance selected six lines which have early maturity and large seed size, hence they could be further evaluated in several locations in the next breeding stage.


2021 ◽  
Vol 911 (1) ◽  
pp. 012020
Author(s):  
Jamaluddin ◽  
Paesal ◽  
Syuryawati ◽  
Muzdalifah ◽  
Abdul Fattah

Abstract In the last decade, purple corn gain more attention mainly due to its high nutritional value and attractive color appearance. Purple corn contain anthocyanin 350% higher than normal corn. Based on its excellence, the research was conducted to find out of high yield purple opv corn with good resistance to downy mildew. The experiment was conducted by using randomized block design with three replication. The variable observed including agronomic character like vegetative, generative and scored disease of downy meldows. The result showed that two opve candidate were PMU(S1).Synth.F.C1 and PMU(S1).Synth.D.C1 have the highest yield6,80-6,85 t/ha, higher 50% than PLU. C0 (check). PMU(S1).Synth.F.C1 showed moderate resistence to downy meldows (20%-35%) and PMU(S1).Synth.D.C1 susceptible (>60%).


2019 ◽  
Vol 18 (2) ◽  
pp. 95
Author(s):  
Suriani . ◽  
Nurasiah Djaenuddin ◽  
A.Haris Talanca

Correlation of stomata density to rust severity on some accessions of maize germplasm. Rust is an important disease on maize. Control of rust using resistant varieties is recommended because it is more practical and environmental friendly. This research aims to study on the correlation of stomata density to rust severity on the several maize germplasm accessions. The research was conducted in Bontobili Farm Experimental Station and ICERI Pathology Laboratory, held from March to August 2017; it used Randomized Block Design with 2 replicates. As much as 30 corn germplasm accessions and 2 varieties for comparison (Bima 10 and Anoman) were planted by spacing 20 x 70 cm. The inoculation of Puccinia sp. was allowed to occur naturally. Printing of stomata was conducted with painted the lower part of corn leaf with nail polish transparent. After drying, it was pasted with clear isolation and then it was pulled and saved on glass object. Observed parameters were rust severity on the age of 50, 60, 70 days after planting and density of stomata. Results of the experiment showed that disease severity of germplasm accession number 2, 218 and 243 were not significant with comparison (tolerant variety). Germplasm with accession number 234 was categorized tolerant to rust. The rust infection rate on all accession were categorized by mild to moderate. Density of stomata of each maize germplasm accession was significantly correlated with rust severity, the increase of stomata density could increase of rust severity at 0.73%.


2020 ◽  
Vol 142 ◽  
pp. 03007
Author(s):  
Sholeh Avivi ◽  
Silvia Fitri Mei Arini ◽  
Sigit Soeparjono ◽  
Didik Pudji Restanto ◽  
Wahyu Indra Duwi Fanata ◽  
...  

The aim of this research was to obtain the resistant plant toward waterlogging stress. The research used complete randomized block design (RBD) with two factors and three replications. The first factors of sugarcane variety are PS 8845, VMC 7616, BL, VMC 86550, PSJK 922 and PS 864. The second factor is the treatments of waterlogging on the level of treatment, that is, without waterlogging, 6, 9, and 12 weeks of waterlogging in bucket. The research results showed that the differences in resistance response of several tested varieties were seen in parameters of number of leaves, number of yellowing leaves, fresh weight of plant, plant height, stem diameter, root length, root’s branch, number of tillers, chlorophyll content, the rate of photosynthesis, stomatal density, shoot leaf size, and leaf angle. Quantitative data character were analysed using ANOVA and DMRT. The conclusion of this research were that PS 8845 and VMC 7616 variety can be recommended as a variety that is resistant to water logging stress. While variety PSJK 922 showed the worst response in condition of waterlogging stress.


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