scholarly journals Assessing Genetic Resistance in Wheat to Black Point Caused by Six Fungal Species in the Yellow and Huai Wheat Area of China

Plant Disease ◽  
2020 ◽  
Vol 104 (12) ◽  
pp. 3131-3134
Author(s):  
Qiaoyun Li ◽  
Mengyu Li ◽  
Yumei Jiang ◽  
Siyu Wang ◽  
Kaige Xu ◽  
...  
Keyword(s):  
Disease Incidence ◽  
Genetic Resistance ◽  
Bipolaris Sorokiniana ◽  
Triticum Aestivum L ◽  
Fungal Species ◽  
Field Conditions ◽  
Sources Of Resistance ◽  
Black Point ◽  
Environmentally Sustainable ◽  
Resistant Cultivars

The most effective and environmentally sustainable method for controlling black point disease of wheat (Triticum aestivum L.) is to plant resistant cultivars. To identify sources of resistance to black point, 165 selected cultivars/lines were inoculated with isolates of six fungal species (Bipolaris sorokiniana, Alternaria alternata, Fusarium equiseti, Exserohilum rostratum, Epicoccum sorghinum, and Curvularia spicifera) known to cause black point in wheat using spore suspensions under controlled field conditions in 2016 and 2017. Inoculation of the isolates significantly increased the incidence of black point in the cultivars/lines compared with those grown under natural field conditions (NFC). The disease incidence of plants inoculated with B. sorokiniana and E. rostratum was 15.5% and 18.8% in 2016, and 20.4% and 23.0% in 2017, whereas those under NFC were 5.7% (2016) and 1.5% (2017), respectively. Furthermore, disease symptoms varied with pathogen. Among the 165 cultivars/lines tested, 3.6%, 50.9%, 60.0%, 1.8%, 47.3%, and 58.8% were resistant to B. sorokiniana, A. alternata, F. equiseti, E. rostratum, E. sorghinum, and C. spicifera, respectively. In addition, we identified one line (‘SN530070’) resistant to black point caused by all six pathogens. This is the first study to assess resistance to wheat black point caused by six fungal species under controlled conditions. The black point-resistant cultivars/lines could be useful in breeding and also in research on the mechanisms of resistance to black point.

scholarly journals Screening of Selected Sorghum Genotypes for Resistance to Covered Kernel Smut Disease in Western Kenya

2021 ◽  
Vol 13 (7) ◽  
pp. 63
Author(s):  
Okongo Caroline ◽  
Ouma Evans ◽  
Gudu Samuel
Keyword(s):  
Abiotic Factors ◽  
Disease Incidence ◽  
Field Conditions ◽  
Test Results ◽  
Yield Losses ◽  
Important Food ◽  
Sources Of Resistance ◽  
Western Kenya ◽  
Sorghum Genotypes ◽  
The University

Sorghum is an important food security crop for arid and semi-arid tropics but its production is hampered by many biotic and abiotic factors including covered kernel smut disease (CKSD) caused by fungus Sporosorium sorghi in the Ustilaginaceae family. The disease attacks susceptible sorghum genotypes causing yield losses estimated at 43% in Western Kenya. This study determined the response of selected sorghum genotypes to CKSD under field and greenhouse conditions. A total of 15 elite sorghum genotypes were screened under field conditions in Migori and Homa Bay sites and under greenhouse at the University of Eldoret. Data on disease incidence and severity were collected per genotype and analyzed using R-Studio software and means were separated at 1% using Tukey’s test. Results showed significant differences among genotypes for disease incidence and severity under fields and greenhouse conditions. Disease incidence varied significantly (p < 0.001) among the genotypes ranging from zero (for T53, T30, IS3092, N4 and N68) to 64% (for Nyadundo2) under field conditions but ranged from 0-69% under greenhouse conditions. Similarly, severity followed the same trend with C26 having the worst attack with a score of 5 while T53 recorded the least (score of 1). This study has identified potential sources of resistance for covered kernel smut disease that can be utilized to manage the disease and significantly improve sorghum yields in the target regions.

scholarly journals Bean Rust Control under Field Conditions with Systemic and Contact Fungicides.

1969 ◽  
Vol 70 (1) ◽  
pp. 45-55
Author(s):  
Pedro L. Meléndez ◽  
Rocío Rodríguez ◽  
Linda Wessel-Beaver
Keyword(s):  
Puerto Rico ◽  
Disease Incidence ◽  
Genetic Resistance ◽  
Field Conditions ◽  
Uromyces Appendiculatus ◽  
Bean Rust ◽  
Disease Symptoms ◽  
Systemic Fungicides

Bean rust (Uromyces appendiculatus) was generally controlled with both contact and systemic fungicides on three cultivars (Blanca del País, Bountiful and Naranjito) tested at two locations in Puerto Rico. However, effectiveness varied with rate, cultivar, location and disease level. On cultivars in Lajas, contact fungicides chlorothalonil and mancozeb were more effective in reducing disease symptoms and in increasing yields than the systemic fungicides oxycarboxin and triforine. There were fewer differences between fungicides in Isabela, where disease incidence was lower, but contact fungicides again were generally more effective. Mancozeb was the most effective fungicide, reducing disease symptoms and increasing yields. Certain fungicides combined with genetic resistance should be effective in increasing bean yields.

Screening the Peanut Core Collection for Resistance to Tomato Spotted Wilt Virus

1996 ◽  
Vol 23 (1) ◽  
pp. 57-61 ◽  
Author(s):  
W. F. Anderson ◽  
C. C. Holbrook ◽  
A. K. Culbreath
Keyword(s):  
Core Collection ◽  
Tomato Spotted Wilt Virus ◽  
Disease Incidence ◽  
Field Trials ◽  
Stepwise Multiple Regression ◽  
Sources Of Resistance ◽  
Plant Introductions ◽  
Resistant Cultivars ◽  
Tomato Spotted Wilt ◽  
Wilt Virus

Abstract Tomato spotted wilt virus (TSWV) is among the greatest yield-reducing viruses affecting peanut (Arachis hypogaea L.). The best known method of control of TSWV is through the use of resistant cultivars. Unfortunately, only a few peanut genotypes with moderate levels of resistance are known. The objectives of this study were to identify additional sources of resistance to TSWV and to determine whether plant descriptor information is associated with reaction to TSWV in the field. Peanut plant introductions from a core collection were evaluated for resistance to TSWV in field trials from 1991 to 1993. Great variability was found among PIs for reaction to natural TSWV epidemics at Attapulgus, GA. Accessions which exhibited potential resistance in 1991 or 1992 were reevaluated in subsequent years. Disease pressure was high in 1993 and 27 accessions exhibited significantly greater resistance than Florunner, and one (PI 262049) had lower disease incidence than Southern Runner. Only minor relationships existed between TSWV incidence and plant descriptor traits (growth habit and maturity) using the stepwise multiple regression procedure. Peanut accessions with resistance to TSWV were found among all maturity levels and growth habits. These accessions provide additional parents and may provide additional genes for resistance that may be useful in developing resistant cultivars.

scholarly journals Field Evaluation of Tomato Cultivars for Tolerance to Tomato Chlorotic Spot Tospovirus

2019 ◽  
Vol 20 (2) ◽  
pp. 77-82 ◽  
Author(s):  
Shouan Zhang ◽  
Xiaohui Fan ◽  
Yuqing Fu ◽  
Qingren Wang ◽  
Eugene McAvoy ◽  
...  
Keyword(s):  
Frankliniella Occidentalis ◽  
Disease Incidence ◽  
Total Yield ◽  
Genetic Resistance ◽  
Field Evaluation ◽  
South Florida ◽  
Fruit Yield ◽  
Field Conditions ◽  
Chlorotic Spot ◽  
Tomato Cultivars

Fourteen tomato cultivars resistant to tomato spotted wilt tospovirus (TSWV) were evaluated for their tolerance against tomato chlorotic spot tospovirus (TCSV) under field conditions during the 2014–2015 and 2015–2016 growing seasons in Homestead, FL. All TSWV-resistant tomato cultivars had significantly (P < 0.05) lower disease incidence of TCSV, compared with the commercial standard cultivars ‘FL 47’ or ‘Sanibel’, exhibiting intermediate to high levels of tolerance to TCSV. There was no significant effect of tomato genotype on the thrips vectors, western flower thrips (Frankliniella occidentalis) and common blossom thrips (F. schultzei). All tested tomato cultivars had equivalent or greater yields of total marketable fruit compared with the standard cultivar Sanibel. Particularly, in the third trial with disease incidence of 25% on Sanibel, ‘BHN 1064’ had significantly greater total yield and yields of extra-large and large fruit compared with Sanibel. ‘SV 7631TD’ and ‘Brickyard’ had significantly greater extra-large fruit yield and medium fruit yield, respectively, compared with Sanibel. Results from this study show that TSWV-resistant tomato cultivars were tolerant to TCSV under field conditions of south Florida, indicating that the use of genetic resistance in commercial tomato cultivars is an effective strategy to manage TCSV.

scholarly journals Cultural practices and genetic resistance as factors affecting soybean stem canker and plant yield in the Cerrado

2002 ◽  
Vol 27 (1) ◽  
pp. 5-11 ◽  
Author(s):  
MARCOS A. FREITAS ◽  
ADALBERTO C. CAFÉ FILHO ◽  
LUIZ C. B. NASSER
Keyword(s):  
Field Experiments ◽  
Cultural Practices ◽  
Disease Incidence ◽  
Genetic Resistance ◽  
Stem Canker ◽  
Disease Development ◽  
Resistant Cultivars ◽  
Plant Densities ◽  
Plant Yields ◽  
Moderately Resistant

Field experiments were conducted in the 1995-96 soybean (Glycine max) growing season to evaluate the effects of cultural practices and host genetic resistance on the intensity of soybean stem canker, caused by Diaporthe phaseolorum f.sp. meridionalis (Dpm). Experiments were conducted in a commercial field severely infected in the previous (1994-95) season. In one study, minimum tillage (MT) and no-tillage (NT) cropping systems were investigated for their effects on disease development and on plant yields in cvs. FT-Cristalina (susceptible) and FT-Seriema (moderately resistant). Another study evaluated the effects of plant densities (8, 15, 21 and 36 plants/m) on disease development in cvs. FT-Cristalina, FT-101 (moderately resistant) and FT-104 (resistant). Disease incidence and severity were consistently lower in NT than in MT, and plant yields were increased by 23% and 14% in the NT system for the susceptible and moderately resistant cultivars, respectively, compared to the yields in the MT system. The Gompertz and Logistic models described well the disease progress curves in all situations. For both susceptible and moderately resistant cultivars, disease severity increased proportionately to the increase in plant densities. At the end of the season, 100% of the plants of cv. FT-Cristalina were infected by Dpm, at all plant densities. Disease levels on cv. FT-101 were intermediate while only very low disease levels were recorded on cv. FT-104. There was a consistent negative correlation between stem canker severity and yield. Some practices demonstrated potential for direct application in disease control, and could be combined considering their additive effects.

scholarly journals Colletotrichum lindemuthianum Races Prevalent on Dry Beans in North Dakota and Potential Sources of Resistance

Plant Disease ◽  
2011 ◽  
Vol 95 (4) ◽  
pp. 408-412 ◽  
Author(s):  
Rubella S. Goswami ◽  
Luis E. del Rio-Mendoza ◽  
Robin S. Lamppa ◽  
Jeff Prischmann
Keyword(s):  
United States ◽  
North Dakota ◽  
Disease Incidence ◽  
Genetic Resistance ◽  
The United States ◽  
Colletotrichum Lindemuthianum ◽  
Sources Of Resistance ◽  
Dry Bean ◽  
New Races ◽  
Major Resistance Genes

Anthracnose caused by Colletotrichum lindemuthianum is one of the most important diseases of dry edible beans in the major production areas worldwide. This pathogen is highly variable, with numerous races. Disease management relies heavily on genetic resistance and use of clean seed. Genetic resistance is controlled by major resistance genes conferring protection against specific races of the pathogen. Therefore, knowledge of the pathogen population in a region is essential for effective screening of germplasm. Surveys were conducted for more than 6 years in North Dakota, the largest dry-bean-growing state in the United States, and seed samples submitted for certification were assessed to identify the C. lindemuthianum races prevalent in the region. A collection of commercial cultivars from different market classes of dry bean was also screened for resistance to these races. Disease incidence was found to be low in most years. However, in addition to the previously reported races of anthracnose 7, 73, and 89, two new races, 1153 and 1161, previously never reported in the United States, were identified and the commercial cvs. Montcalm, Avalanche, Vista, and Sedona where found to possess resistance to these races.

scholarly journals Improvements in Hazelnuts in the United States

HortScience ◽  
2011 ◽  
Vol 46 (3) ◽  
pp. 343-344
Author(s):  
Jeff Olsen
Keyword(s):  
United States ◽  
Genetic Resistance ◽  
The United States ◽  
Management Program ◽  
Breeding Program ◽  
Eastern United States ◽  
Multiple Sources ◽  
Sources Of Resistance ◽  
Resistant Cultivars ◽  
Beneficial Traits

In the mid-1980s, eastern filbert blight (EFB) fungus, Anisogramma anomala (Peck) E. Müller, was discovered in Oregon's main hazelnut-producing region and now is present throughout the hazelnut-producing area. Oregon State University's (OSU) Hazelnut Breeding Program responded by developing EFB-resistant cultivars, the first of which was released in 2005. The breeding program has also selected for other beneficial traits such as uniform early nut maturation, larger kernel size, and improved kernel quality. A 2008 OSU economic study on the costs of establishing and producing hazelnuts showed that the EFB-resistant cultivars enhanced economic viability of orchards, increasing cumulative cash flow during the 12-year establishment period by $12,243 per hectare. Several completely resistant cultivars have been released from the OSU Hazelnut Breeding program, all of which have ‘Gasaway’ as a resistance source, which transmits a dominant allele at a single locus that provides resistance to EFB. Additional EFB-resistant genotypes have also been identified from a diversity of origins that are being integrated into the OSU breeding program to produce new cultivars expressing multiple sources of genetic resistance. Interest in growing hazelnuts is increasing in other parts of the United States; for example, the Arbor Day Foundation began the Hazelnut Research Project in 1996 in Nebraska. A Hybrid Hazelnut Consortium was formed to join the leading hazelnut researchers in the United States. The Consortium's goal is to create a world-leading research and breeding program to develop hazelnuts as a widely adapted, high-yielding, and low-input sustainable crop that is competitive with annual crops for food, feed, or bioenergy. At Rutgers University, there has been a program of breeding and research for hazelnuts for the eastern United States since 1996. The program currently has ≈11,000 hazelnut seedlings undergoing evaluation. The Rutgers program is also looking for winter-hardy genotypes. They have been working closely with OSU to assess the response of OSU hazelnut selections that are resistant to EFB in Oregon when they are exposed to EFB isolates collected from across the eastern United States. This work has demonstrated the need for cultivars to express multiple sources of resistance and has prompted quarantine on importation of hazelnut plants into Oregon from other states where EFB strains may differ. Rutgers is also searching for new sources of resistance to EFB from seedling populations from Europe with the goal of integrating these sources into American germplasm. More effective Integrated Pest Management for EFB-susceptible hazelnut cultivars has been developed by OSU scientists. They recommend a management program that integrates scouting for and pruning infected tissue, fungicidal sprays, and the use of more resistant cultivars. Advances in hazelnut fertilizer management have included descriptions of patterns of nitrogen uptake, distribution, and use using isotopically labeled nitrogen.

RESISTANCE IN WHEAT TO BLACK POINT CAUSED BY Alternaria alternata AND Cochliobolus sativus

1988 ◽  
Vol 68 (2) ◽  
pp. 351-359 ◽  
Author(s):  
R. L. CONNER ◽  
J. G. N. DAVIDSON
Keyword(s):  
Spring Wheat ◽  
Alternaria Alternata ◽  
Disease Incidence ◽  
Triticum Aestivum L ◽  
Cochliobolus Sativus ◽  
Wheat Cultivars ◽  
Canadian Prairies ◽  
Black Point ◽  
Hard Red Spring Wheat ◽  
Low Incidence

A 2-yr field study conducted at six locations on the Canadian prairies identified seven wheat (Triticum aestivum L. em Thell.) cultivars that consistently had low incidence of black point. These resistant wheats included the hard red spring wheat cultivars Sinton, Park, Thatcher, Benito and Era, the utility wheat Glenlea, and the soft white spring wheat line SWS15 (ICARDA 15). In separate tests, the inoculation of resistant wheat cultivars with Alternaria alternata (Fr.) Keissler or Cochliobolus sativus (Ito and Kurib.) Drechs. ex Dastur under controlled environmental conditions revealed significant differences in black point incidence. All cultivars were more resistant to A. alternata than the susceptible cultivar Fielder. Glenlea and Era were more resistant to A. alternata than all the other cultivars. Only the cultivars Thatcher, Benito, and Sinton were more resistant to C. sativus than Fielder. A test comparing black point incidence caused by the two fungi found that certain cultivars differed significantly in disease incidence caused by A. alternata and C. sativus. Cochliobolus sativus produced less disease in Fielder and Sinton than A. alternata, but the reverse was true for Glenlea. These results indicate that resistance to A. alternata and C. sativus is under different genetic control in certain cultivars.Key words: Wheat (spring), black point, Alternaria alternata, Cochliobolus sativus

Characterization of elite bread wheat (Triticum aestivum L.) germplasm for spot blotch Bipolaris sorokiniana (Sacc.) Shoemaker resistance

2021 ◽  
pp. 1-8
Author(s):  
Deep Shikha ◽  
Chandani Latwal ◽  
Elangbam Premabati Devi ◽  
Anupama Singh ◽  
Pawan K. Singh ◽  
...  
Keyword(s):  
Abiotic Stress Tolerance ◽  
Bipolaris Sorokiniana ◽  
Triticum Aestivum L ◽  
Spot Blotch ◽  
Biotic And Abiotic Stress ◽  
Wheat Varieties ◽  
Effective Measure ◽  
Breeding Lines ◽  
Elite Breeding Lines ◽  
Germplasm Accessions

Abstract Genetic resources are of paramount importance for developing improved crop varieties, particularly for biotic and abiotic stress tolerance. Spot blotch (SB) is a destructive foliar disease of wheat prevalent in warm and humid regions of the world, especially in the eastern parts of South Asia. For the management of this disease, the most effective measure is the development of resistant cultivars. Thus, the present investigation was carried out to confirm SB resistance in 200 germplasm accessions based on phenotypic observations and molecular characterization. These elite breeding lines obtained from the International Centre for Maize and Wheat Improvement, Mexico, are developed deploying multiple parentages. These lines were screened for SB resistance in the field under artificially created epiphytotic conditions during 2014–15 and 2015–16 along with two susceptible checks (CIANO T79 and Sonalika) and two resistant checks (Chirya 3 and Francolin). Eighty-two out of 200 germplasm accessions were found resistant to SB and resistance in these lines was confirmed with a specific SSR marker Xgwm148. Three accessions, VORONA/CNO79, KAUZ*3//DOVE/BUC and JUP/BJY//URES/3/HD2206/HORK//BUC/BUL were observed possessing better resistance than the well-known SB-resistant genotype Chirya3. These newly identified resistant lines could be used by wheat breeders for developing SB-resistant wheat varieties.

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