scholarly journals RESISTANCE EVALUATION ON POPULATIONS OF CROSSES BETWEEN TRANSGENIC POTATO KATAHDIN RB AND NON-TRANSGENIC ATLANTIC AND GRANOLA TO LATE BLIGHT (Phytophthora infestans) IN CONFINED FIELD TRIAL

2011 ◽  
Vol 12 (1) ◽  
pp. 33 ◽  
Author(s):  
Alberta Dinar Ambarwati ◽  
Muhammad Herman ◽  
Agus Purwito ◽  
Sientje Mandang Sumaraw ◽  
Hajrial Aswidinnoor
Keyword(s):  
Late Blight ◽  
Phytophthora Infestans ◽  
Resistance Gene ◽  
Field Trial ◽  
Transgenic Potato ◽  
Solanum Bulbocastanum ◽  
Resistance Level ◽  
Progress Curve ◽  
Resistance Score ◽  
Confined Field Trial

Late blight resistance gene (RB gene) isolated from Solanum bulbocastanum, is a broad resistance gene against all races of Phytophthora infestans. The gene was transformed into Katah-din event SP904 and SP951 using Agrobacterium tumefaciens and these transgenic plants have been crossed with susceptible potato cultivars Atlantic and Granola. Populations of the crosses have been molecularly characterized for the integration of the RB transgene. The study aimed to evaluate the resistance of the populations of crosses between transgenic Katahdin RB  and susceptible non-transgenic parents (Atlantic and Granola) to late blight in a confined field trial at Pasir Sarongge, Cianjur, West Java. A total of 84 clones originated from four popula-tions were evaluated for resistance to late blight. These included 22 clones of Atlantic x transgenic Katahdin SP904, 16 clones of Atlantic x transgenic Katahdin SP951, 19 clones of Granola x transgenic Katahdin SP904, and 27 clones of Granola x transgenic Katahdin SP951. Observations of the late blight infection were conducted when late blight symptoms were detected, i.e. at 56, 60, 63, 70, and 77 days after planting (DAP). The result showed there were high variations in the resistance level of all the 84 clones tested. Clones of crosses between susceptible parents (Atlantic or Granola) and resistant parents (transgenic Katahdin SP904 or Katahdin SP951) showed a similar pattern based on the area under disease progress curve (AUDPC) value, i.e. 377.2 greater than the AUDPC of the resistant parents (180.1), but smaller than that of the susceptible parents (670.7). Observation at 77 DAP resulted four resistant potato clones having resistance score of 7.0-7.6, higher than the transgenic parents Katahdin SP904 (4.6) and Katahdin SP951 (6.8), i.e. clone B8 (Atlantic x transgenic Katahdin SP951) with resistance score of 7.6 and clones B26 (Atlantic x transgenic Katahdin SP951), C183 (Granola x transgenic Katahdin SP904), and D89 (Granola x transgenic Katahdin SP951) with resistance score of 7. These four transgenic potato resistant clones need to be further developed as promising potato clones to late blight.<br /><br />

scholarly journals Pengujian Ketahanan Klon-klon Hasil Silangan Tanaman Kentang Transgenik dengan Nontransgenik terhadap Penyakit Hawar Daun Phytophthora infestans di Lapangan Uji Terbatas

2013 ◽  
Vol 22 (2) ◽  
pp. 187 ◽  
Author(s):  
Alberta Dinar Ambarwati ◽  
Muhamad Herman ◽  
Edi Lisanto ◽  
Euis Suryaningsih ◽  
Eri Sofiari
Keyword(s):  
Late Blight ◽  
Phytophthora Infestans ◽  
Field Trial ◽  
Durable Resistance ◽  
Transgenic Potato ◽  
Resistance Testing ◽  
Solanum Bulbocastanum ◽  
Phenotypic Resistance ◽  
Rb Gene ◽  
Confined Field Trial

STRAK. Tanaman kentang transgenik Katahdin event SP904 dan SP951 mengandung gen RB, yang diisolasi dari spesies liar kentang diploid Solanum bulbocastanum. Gen RB mempunyai ketahanan yang bersifat  durable dengan spektrum yang luas terhadap ras-ras Phytophthora  infestans di Amerika Serikat. Dalam perakitan tanaman kentang tahan penyakit hawar daun P. infestans di Indonesia, transgenik Katahdin dijadikan sebagai donor tahan dalam persilangan dengan varietas rentan Atlantik dan Granola. Klon-klon hasil silangan dianalisis secara molekuler mengandung gen RB. Penelitian dilakukan untuk menguji ketahanan klon-klon hasil silangan tanaman kentang transgenik dengan nontransgenik terhadap isolat P. infestans di lapangan uji terbatas (LUT) yang berlokasi di Balai Penelitian Tanaman Sayuran (Balitsa), Lembang dari bulan Oktober 2009 sampai dengan Maret 2010. Klon-klon yang diuji ialah 12 klon hasil silangan Atlantik x transgenik Katahdin SP904 (A); 15 klon hasil silangan Atlantik x transgenik Katahdin SP951 (B); 17 klon hasil silangan Granola x transgenik Katahdin SP904 (C); dan 20 klon hasil silangan Granola x transgenik Katahdin SP951 (D). Atlantik dan Granola digunakan sebagai kontrol rentan, sedangkan transgenik Katahdin sebagai kontrol tahan. Pengamatan dimulai ketika muncul gejala awal, yaitu pada 26, 32, 39, 46, dan 53 hari setelah tanam. Ketahanan tanaman semakin menurun dengan bertambahnya periode pengamatan, diikuti meningkatnya intensitas penyakit dan AUDPC. Semua klon yang diuji menunjukkan keragaman dalam ketahanan fenotipik terhadap hawar daun P. infestans. Klon-klon hasil silangan Atlantik x transgenik Katahdin SP951 mempunyai nilai AUDPC 697, yang hampir sama dengan transgenik Katahdin SP904 yaitu 698,5. Klon-klon Granola x transgenik Katahdin SP951 mempunyai nilai AUDPC  687,5 lebih kecil dibandingkan transgenik Katahdin SP904. Hasil penelitian ini juga menunjukkan bahwa klon-klon tersebut mempunyai ketahanan yang lebih tinggi dibandingkan transgenik Katahdin SP904. Pada pengamatan 46 hari setelah tanam atau 20 hari setelah infeksi diperoleh tiga klon tahan yaitu B49 (skor 7,5), C111 (skor 7,1), dan D26 (skor 7,3). Ketahanan ini lebih tinggi daripada transgenik Katahdin SP904 (skor 5,1) dan transgenik Katahdin SP951 (skor 6,4). <br /><br />ABSTRACT. Ambarwati, AD, Herman, M, Listanto, E, Suryaningsih, E and Sofiari, E 2012. Resistance Testing on Transgenic and Nontransgenic Potato Clones Against Late Blight Phytophthora  infestans in Confined Field Trial.  Transgenic potato Katahdin event SP904 and  SP951 containing RB gene, which were isolated from a wild diploid potato species, Solanum bulbocastanum. RB gene showed durable resistance with broad spectrum to all known races of  P. infestans in the USA. In development of  potato resistant to late blight P. infestans in Indonesia, Katahdin transgenic were used as a resistant donor and crossed with susceptible varieties i.e. Atlantic and Granola. Clones derived from the crossing were molecularly analyzed and had RB gene contain. Experiment was conducted to assess the resistance of the clones derived from crossing of Katahdin transgenic and nontransgenic to P. infestans in confined field trial (CFT), located at the Indonesian Vegetable Research Institute (IVEGRI), Lembang from October 2009 to March 2010. Several clones tested were 12 clones of Atlantic x Katahdin transgenic SP904 (A); 15 clones of Atlantic x Katahdin transgenic SP951 (B); 17 clones of Granola x Katahdin transgenic SP904 (C); and 20 clones of Granola x Katahdin transgenic SP951 (D). Atlantic and Granola were used as susceptible control whereas Katahdin transgenic as resistant control. Observation was started as late blight symptoms and detected at 26, 32, 39, 46, and 53 days after planting. Plant resistance decreases with increasing period of observation, followed by increasing disease intensity and AUDPC. All clones tested showed variation in phenotypic resistance to late blight P. infestans. Clones derived from crossing of Atlantic x Katahdin transgenic SP951 had AUDPC score 697 and almost similar to Katahdin transgenic SP904 (698.5). Clones derived from crossing of Granola x Katahdin transgenic SP951 had AUDPC score 687.5 and smaller than Katahdin transgenic SP904. The results also indicated that these clones had higher resistance than Katahdin transgenic SP904. Observation at 46 days after planting or 20 days after infection resulted three resistant clones i.e. B49 (score 7.5), C111 (score 7.1); and D26 (score 7.3).  This resistance was higher than Katahdin transgenic SP904 (score 5.1) and Katahdin transgenic SP951 (score 6.4). <br />

scholarly journals Performance of Transgenic Potato Containing the Late Blight Resistance Gene RB

Plant Disease ◽  
2008 ◽  
Vol 92 (3) ◽  
pp. 339-343 ◽  
Author(s):  
Dennis A. Halterman ◽  
Lara Colton Kramer ◽  
Susan Wielgus ◽  
Jiming Jiang
Keyword(s):  
Late Blight ◽  
Resistance Gene ◽  
Late Blight Resistance ◽  
Transgenic Potato ◽  
Field Trials ◽  
Blight Resistance ◽  
Solanum Bulbocastanum ◽  
Wild Potato Species ◽  
Foliar Resistance ◽  
In The Wild

Late blight of potato, caused by Phytophthora infestans, is one of the most devastating diseases of potato. A major late blight resistance gene, called RB, previously was identified in the wild potato species Solanum bulbocastanum through map-based cloning. The full-length gene coding sequence, including the open reading frame and promoter, has been integrated into cultivated potato (S. tuberosum) using Agrobacterium-mediated transformation. RB-containing transgenic plants were challenged with P. infestans under optimal late blight conditions in greenhouse experiments. All transgenic lines containing RB exhibited strong foliar resistance. Field-grown transgenic tubers also were tested for resistance to P. infestans. In contrast to the foliar resistance phenotype, RB-containing tubers did not exhibit increased resistance. Two years of field trials were used to ascertain whether the presence of RB had any effect on tuber yield. We were unable to detect any significant effect on tuber size or yield after addition of the resistance gene to several S. tuberosum cultivars.

scholarly journals Late Blight Resistance of RB Transgenic Potato Lines

2007 ◽  
Vol 132 (6) ◽  
pp. 783-789 ◽  
Author(s):  
Joseph C. Kuhl ◽  
Kelly Zarka ◽  
Joseph Coombs ◽  
William W. Kirk ◽  
David S. Douches
Keyword(s):  
Late Blight ◽  
Resistance Gene ◽  
Late Blight Resistance ◽  
Transgenic Potato ◽  
Kanamycin Resistance ◽  
Field Resistance ◽  
State University ◽  
Solanum Bulbocastanum ◽  
Native Promoter ◽  
Transgenic Lines

Late blight of potato (Solanum tuberosum L.), incited by Phytophthora infestans (Mont.) de Bary, is a devastating disease affecting tuber yield and storage. Recent work has isolated a resistance gene, RB, from the wild species Solanum bulbocastanum Dun. Earlier work in Toluca, Mexico, observed significant levels of field resistance under intense disease pressure in a somatic hybrid containing RB. In this study, five transgenic RB lines were recovered from the late blight susceptible line MSE149-5Y, from the Michigan State University (MSU) potato breeding program. Transgenic lines were molecularly characterized for the RB transgene, RB transcript, and insertion number of the kanamycin resistance gene NPTII. Transgenic lines and the parent line were evaluated for resistance in field and laboratory tests. Molecular characterization alone did not predict which lines were resistant. Three of the RB transformed MSE149-5Y lines showed increased resistance under field conditions at MSU and increased resistance in detached leaf evaluations using multiple isolates individually (US-1, US-1.7, US-8, US-10, and US-14). Transfer of RB into late blight susceptible and resistant lines could provide increased protection to potato late blight. The use of the RB gene for transformation in this way creates a partially cisgenic event in potato because the gene's native promoter and terminator are used. This type of transformation provides a chance to generate greater public acceptance of engineered approaches to trait introgression in food crops.

Localization of Ds-transposon containing T-DNA inserts in the diploid transgenic potato: linkage to the R1 resistance gene against Phytophthora infestans (Mont.) de Bary

Genome ◽  
1996 ◽  
Vol 39 (2) ◽  
pp. 249-257 ◽  
Author(s):  
A. El-Kharbotly ◽  
J. M. E. Jacobs ◽  
B. te Lintel Hekkert ◽  
W. J. Stiekema ◽  
A. Pereira ◽  
...  
Keyword(s):  
Solanum Tuberosum ◽  
Phytophthora Infestans ◽  
Resistance Gene ◽  
Dna Sequences ◽  
Transgenic Potato ◽  
Potato Genome ◽  
Rflp Map ◽  
Polymerase Chain ◽  
R1 Gene ◽  
Map Location

The Dissociation transposable element (Ds) of maize containing NPTII was introduced into the diploid potato (Solanum tuberosum) clone J91-6400-A16 through Agrobacterium tumefaciens mediated transformation. Genomic DNA sequences flanking the T-DNAs from 312 transformants were obtained with inverse polymerase chain reaction or plasmid rescue techniques and used as probes for RFLP linkage analysis. The RFLP map location of 60 T-DNAs carrying Ds–NPTII was determined. The T-DNA distribution per chromosome and the relative distance between them appeared to be random. All 12 chromosomes have been covered with Ds-containing T-DNAs, potentially enabling tagging of any gene in the potato genome. The T-DNA insertions of two transformants, BET92-Ds-A16-259 and BET92-Ds-A16-416, were linked in repulsion to the position of the resistance gene R1 against Phytophthora infestans. After crossing BET92-Ds-A16-416 with a susceptible parent, 4 desired recombinants (Ds carrying T-DNA linked in coupling phase with the R1 gene) were discovered. These will be used for tagging the R1 gene. The efficiency of the pathway from the introduction to localization of T-DNAs is discussed. Key words : Solanum tuberosum, Phytophthora infestans, Ds element, transposon tagging, R genes, euchromatin.

scholarly journals Uji Ketahanan Klon Kentang Hasil Pesilangan Atlantic x Repita terhadap Penyakit Hawar Daun Phytophthora infestans

Agrikultura ◽  
2018 ◽  
Vol 29 (2) ◽  
pp. 100
Author(s):  
Helmi Kurniawan ◽  
Ineu Sulastrini ◽  
Tarkus Suganda
Keyword(s):  
Late Blight ◽  
Phytophthora Infestans ◽  
Field Test ◽  
Block Design ◽  
Environmentally Friendly ◽  
Statistical Test ◽  
The Other ◽  
Resistant Variety ◽  
Resistance Level ◽  
Randomized Block Design

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

scholarly journals Classifying the Relative Host Reaction in Potato Cultivars and Breeding Lines to the US-8 Strain of Phytophthora infestans in Minnesota

Plant Disease ◽  
2003 ◽  
Vol 87 (8) ◽  
pp. 983-990 ◽  
Author(s):  
J. C. Jenkins ◽  
R. K. Jones
Keyword(s):  
Late Blight ◽  
Phytophthora Infestans ◽  
Rank Correlation ◽  
The United States ◽  
Spearman Rank Correlation ◽  
Breeding Lines ◽  
Spearman Rank ◽  
Progress Curve ◽  
Tuber Blight ◽  
The Us

A total of 32 commercial cultivars grown in the United States and 15 potato breeding lines and non-U.S. cultivars were evaluated at Rosemount, MN for their reaction to the US-8 strain of Phytophthora infestans. Commercial red-, russet-, and white-skinned cultivars tested in the commercial cultivar trial (COMC) in 1996 and 1997 were susceptible (S) to moderately susceptible (MS) to this organism, except for Elba, which ranked as moderately resistant (MR). Yellow-fleshed cvs. Hertha, Santé, and Agria were screened in the late blight nursery (LB1) in 1997 and 1998 and classified as S to MS while Island Sunshine, Brador, and Aziza were classified as MR. The Scottish breeding line G6582-3 and U.S. breeding lines A90586-11, AWN86514-2, AWN85624-5, B0692-4, B0718-3, and B0767-2 were classified as resistant (R). Comparison among entries was based on the area under the disease progress curve (AUDPC). Spearman rank correlation for AUDPC in the 1996 and 1997 COMC trials at 14 to 18 days after inoculation (r = 0.65, P < 0.01) was greater than any other interval tested. The Spearman rank correlation for AUDPC in the 1997 and 1998 LB1 trials at 14 to 18 days after inoculation was r = 0.87, P < 0.01 and increased only slightly in successive assessment dates, suggesting that, in Minnesota, effective evaluation of the foliar infection of late blight can occur at 18 days after inoculation or later. The average tuber blight incidence for the COMC trials at harvest was 10.0% in 1996 and 9.7% in 1997. The average tuber blight incidence for the LB1 trials at harvest was 4.3% in 1997 and 14.6% in 1998. Pearson correlations between tuber blight incidence and foliar disease for the COMC trials was very low; however, for the LBl trials, it was significant in both 1997 (r = 0.53, P < 0.01) and 1998 (r = 0.53, P < 0.01). Asymptomatic tubers harvested from the COMC trials developed additional tuber blight when stored 28 days at ambient temperatures and still more when stored for another 5 months at 5°C. Surviving tubers of nine entries were planted in field trials during 1997 and 1998 to determine if plants that develop from tubers exposed to P. infestans could manifest late blight in the subsequent season. Late blight failed to develop throughout the trials in either year.

scholarly journals Efficacy of fungicide mixtures for the management of Phytophthora infestans (US-1) on potato

2010 ◽  
Vol 90 (1) ◽  
pp. 19-29 ◽  
Author(s):  
F.N. Muchiri ◽  
R.D. Narla ◽  
O.M. Olanya ◽  
R.O. Nyankanga ◽  
E.S. Ariga
Keyword(s):  
Late Blight ◽  
Phytophthora Infestans ◽  
Tuber Yield ◽  
Severe Disease ◽  
Resistance Management ◽  
Foliar Blight ◽  
Progress Curve ◽  
Fungicide Mixtures ◽  
Spray Regimes ◽  
Disease Pressure

Fungicide application strategies (timing, frequency, rates and mixtures) are important for the control and resistance management of potato late blight caused by Phytophthora infestans. The efficacy of fungicide mixtures consisting of fenamidone + mancozeb and propamocarb HCL + mancozeb at various rates and in spray regimes containing metalaxyl and mancozeb was evaluated for late blight control (US-1) at four locations in Kenya. Propamocarb HCL + mancozeb significantly (P < 0.05) reduced foliar blight compared with mancozeb and the untreated control under moderate to severe disease pressure. Disease severity was significantly lower following application of propamocarb HCL + mancozeb at a rate of 4L ha-1 than at rates of 2L and 3L ha-1 in 1999 and 2000, but it was not significantly lower following applications at a rate of 3L ha-1 in 2000 and 2001. There were no significant differences in mean final late blight score among the three rates of 0.9, 1.0 and 1.1 kg ha-1 of fenamidone + mancozeb. All fungicide mixtures and application sequences significantly reduced the area under the disease progress curve and final late blight scores as compared with the unprotected control. Total and marketable tuber yield significantly (P < 0.05) increased in all fungicide-treated plots.

Resistance to Phytophthora infestans Clonal Lineage US-23 in Potato Cultivars and Its Relationship with Early Blight Resistance and Tuber Yield

Plant Disease ◽  
2021 ◽  
Author(s):  
Weiya Xue ◽  
Kathleen G. Haynes ◽  
Xinshun Qu
Keyword(s):  
Late Blight ◽  
Phytophthora Infestans ◽  
Early Blight ◽  
Tuber Yield ◽  
Late Blight Resistance ◽  
Field Trials ◽  
Potato Cultivars ◽  
Blight Resistance ◽  
Clonal Lineage ◽  
Progress Curve

Resistance to late blight, caused by Phytophthora infestans clonal lineage US-23, in 217 old and modern potato cultivars was evaluated in field trials in 2016 and 2017 in Pennsylvania. Significant differences in resistance were found among these cultivars (P < 0.0001). Significant interaction between cultivars and environments was found (P < 0.0001). The values of relative area under the disease progress curve ranged from 0 to 0.5841 in 2016 and from 0 to 0.5469 in 2017. Broad-sense heritability of late blight resistance was estimated to be 0.91 with a 95% confidence interval of 0.88 to 0.93. Cluster analysis classified the cultivars into 5 groups: resistant, moderately resistant, intermediate, moderately susceptible, and susceptible. Thirty cultivars showing resistance and 32 cultivars showing moderate resistance were identified. The 217 cultivars were also evaluated for foliar maturity, tuber yield and resistance to early blight, caused by Alternaria solani. A few cultivars with late blight resistance independent of late maturity were found. Late blight resistance and early blight resistance were positively correlated, and 17 cultivars possessed resistance to both diseases. Yield tradeoff associated with late blight resistance was not observed among the cultivars in the absence of disease pressure.

STUDIES ON FERTILITY AND LATE BLIGHT RESISTANCE IN SOLANUM BULBOCASTANUM DUN. IN MEXICO

1959 ◽  
Vol 37 (1) ◽  
pp. 41-49 ◽  
Author(s):  
K. M. Graham ◽  
J. S. Niederhauser ◽  
Leopoldo Servin
Keyword(s):  
Late Blight ◽  
Phytophthora Infestans ◽  
Late Blight Resistance ◽  
Field Resistance ◽  
Blight Resistance ◽  
Solanum Bulbocastanum ◽  
Mexican Isolate

Solanum balbocastanum Dun. was collected extensively throughout its range in Mexico and Guatemala. Experimental self- and cross-pollinations showed that the species is highly self-sterile and consists of cross-sterile and cross-fertile individuals. Self-sterility may be due to the presence of incompatibility factors or to triploidy. Authentic hybrids were produced between S. bulbocastanum and S. trifidum Correll, and between S. bulbocastanum and S. pinnatisectum Dun.After inoculation with race 1.2.3.4 of Phytophthora infestans three types of reaction were observed among 1148 seedlings of S. bulbocastanum: immunity with no perceptible lesions, resistance expressed by non-sporulating lesions of the hypersensitive type, and susceptibility indicated by large sporulating necrotic lesions. Seedlings resistant to an isolate of race 1.2.3.4 of Canadian origin did not always show the same level of resistance to a Mexican isolate of the same race. Varying degrees of field resistance were observed among seedling plants, while tuber-propagated plants were generally field immune. Solanum bulbocastanum is considered a mixture of resistant and susceptible genotypes.

scholarly journals Evaluation of potato (Solanum tuberosum L.) genotypes for resistance to late blight at Sinana Southeastern Ethiopia

2016 ◽  
Vol 6 (1) ◽  
pp. 21-25 ◽  
Author(s):  
Getachew Asefa ◽  
Wassu Mohammed ◽  
Tesfaye Abebe
Keyword(s):  
Late Blight ◽  
Phytophthora Infestans ◽  
Agricultural Research ◽  
Solanum Tuberosum L ◽  
Block Design ◽  
Severity Index ◽  
High Yield ◽  
Mean Values ◽  
Progress Curve ◽  
Moderately Resistant

Late blight caused by Phytophthora infestans (Mont.) de Bary, is one of the most significant constraints to potato production in Bale high lands and other regions of Ethiopia. Hence, this requires to develop high yielding and late blight resistant varieties. Therefore, this study was conducted to determine host resistance of potato against Phytophthora infestans in order to develop late blight resistant/tolerant genotypes. The experiment was laid out in randomized complete block design with three replications at Sinana Agricultural Research Center during 2014 main cropping season. The genotypes showed highly significant (P<0.01) differences for all the characters studied. Genotypes exhibited wide ranges of mean values for all characters. The highest total tuber yield (46.1 t ha-1) was obtained from the advanced clone, CIP-392640.524 followed by Belete (41 t ha-1). Late blight appeared early on farmer's cultivar Kellacho (48 days after planting) and late on advanced clones CIP- 399062.102(74 days after planting). Percent severity index (PSI) and area under disease progress curve (AUDPC) ranged from 33.91 to 91.67% and 105 to 2370, respectively. Eleven newly introduced clones and the released variety "Belete" recorded PSI 33 to 39.7% and AUDPC 105 to 264.1. Hence, these genotypes can be categorized as moderately resistant. The study revealed the presence of considerable variability in tested genotypes for economically important traits and the higher chance of selecting genotypes with high yield and moderately resistant to late blight. However, it appears that further evaluation of genotypes across seasons and locations to identify genotypes that could be released as varieties seem to be quite pertinent.Int. J. Agril. Res. Innov. & Tech. 6 (1): 21-25, June, 2016

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