scholarly journals Resistance to Athelia rolfsii and Web Blotch in the U.S. Mini-core Collection

2020 ◽  
Vol 47 (1) ◽  
pp. 17-24
Author(s):  
R.S. Bennett ◽  
K.D. Chamberlin
Keyword(s):  
Core Collection ◽  
Sclerotium Rolfsii ◽  
Germplasm Collection ◽  
Stem Rot ◽  
Sources Of Resistance ◽  
Southern Blight ◽  
Mini Core Collection ◽  
Athelia Rolfsii ◽  
Low Levels ◽  
The U.S

ABSTRACT Athelia rolfsii (=Sclerotium rolfsii) is a soilborne fungus that causes the disease commonly known as southern blight, southern stem rot, stem rot, and white mold. Despite the fact that A. rolfsii is one of the most destructive pathogens of peanut, the U.S. germplasm collection has not been evaluated for resistance to this pathogen. Therefore, 71 of the 112 accessions comprising the U.S. peanut mini-core collection were evaluated in the field for resistance to southern blight in 2016 to 2018 in Oklahoma. Moderate to low levels of southern blight were observed, but four accessions—CC125, CC208, CC559, and CC650—had low levels of disease in 2017 and 2018, the most favourable years for A. rolfsii. Ratings for web blotch, a yield-limiting foliar disease in some production areas caused by Didymella arachidicola, were also taken in 2017 and 2018, when outbreaks occurred. Five entries—CC287, CC155, CC149, CC812, and CC559—had between 10% and 20% disease in 2018, a year when over half of the mini-core accessions exhibited between 50% and 93% disease. Because cultivated peanut in the U.S. has a narrow genetic base, these results will be useful to breeders seeking additional sources of resistance to A. rolfsii and web blotch.

Status of the Arachis Germplasm Collection in the United States

2001 ◽  
Vol 28 (2) ◽  
pp. 84-89 ◽  
Author(s):  
C. C. Holbrook
Keyword(s):  
South America ◽  
Economic Impact ◽  
Core Collection ◽  
Germplasm Collection ◽  
Seed Storage ◽  
The United States ◽  
Cercospora Arachidicola ◽  
Root Knot Nematode ◽  
Sources Of Resistance ◽  
The U.S

Abstract An extensive working collection of Arachis germplasm is maintained by the USDA at the Southern Regional Plant Introduction Sta. in Griffin, GA. Much of this collection is maintained also under long-term seed storage at the Nat. Seed Storage Lab. in Ft. Collins, CO. The working collection consists of 9027 accessions of A. hypogaea and 684 accessions of Arachis species. About half of the A. hypogaea accessions are unimproved landraces collected in the crop's centers of diversity in South America. The other half is comprised of germplasm obtained from countries outside of South America. The U.S. germplasm collection of peanut was the first major germplasm collection to have a working core collection. Research has verified that this core collection can be used to improve the efficiency of germplasm utilization. This has stimulated a great amount of germplasm evaluation work and has resulted in the identification of numerous sources of resistance to several economically significant pathogens. Considerable efforts in the U.S. also have been devoted to the use of wild species of Arachis for sources of resistance to pathogens. Programs are ongoing to introgress high levels of resistance or immunity to early (Cercospora arachidicola Hori) and late (Cercosporidium personatum Berk. & M.A. Curtis) leaf spots, nematodes, and viruses. Genetic resources have been particularly useful in adding disease resistance to peanut cultivars. This has had a significant economic impact on U.S. peanut farmers. The largest impacts have been from the development of cultivars with resistance to Sclerotinia blight (Sclerotinia minor Jagger), the peanut root-knot nematode [Meloidogyne arenaria (Neal) Chitwood race 1], and tomato spotted wilt Tospovirus. Use of these resistant cultivars has an estimated economic impact of more that $200 million annually for U.S. peanut producers.

scholarly journals Pigeonpea composite collection and identification of germplasm for use in crop improvement programmes

2011 ◽  
Vol 9 (01) ◽  
pp. 97-108 ◽  
Author(s):  
H. D. Upadhyaya ◽  
K. N. Reddy ◽  
Shivali Sharma ◽  
R. K. Varshney ◽  
R. Bhattacharjee ◽  
...  
Keyword(s):  
Agronomic Traits ◽  
Crop Improvement ◽  
Germplasm Collection ◽  
Sources Of Resistance ◽  
Abiotic And Biotic Stresses ◽  
Biotic Stresses ◽  
Mini Core Collection ◽  
Breeding Programmes ◽  
Simple Sequence ◽  
High Seed Yield

Pigeonpea (Cajanus cajan(L.) Millsp. is one of the most important legume crops as major source for proteins, minerals and vitamins, in addition to its multiple uses as food, feed, fuel, soil enricher, or soil binder, and in fencing, roofing and basket making. ICRISAT's genebank conserves 13,632 accessions of pigeonpea. The extensive use of few parents in crop improvement is contrary to the purpose of collecting a large number of germplasm accessions and has resulted in a narrow base of cultivars. ICRISAT, in collaboration with the Generation Challenge Program, has developed a composite collection of pigeonpea consisting of 1000 accessions representing the diversity of the entire germplasm collection. This included 146 accessions of mini core collection and other materials. Genotyping of the composite collection using 20 microsatellite or simple sequence repeat (SSR) markers separated wild and cultivated types in two broad groups. A reference set comprising 300 most diverse accessions has been selected based on SSR genotyping data. Phenotyping of the composite collection for 16 quantitative and 16 qualitative traits resulted in the identification of promising diverse accessions for the four important agronomic traits: early flowering (96 accessions), high number of pods (28), high 100-seed weight (88) and high seed yield/plant (49). These accessions hold potential for their utilization in pigeonpea breeding programmes to develop improved cultivars with a broad genetic base. Pigeonpea germplasm has provided sources of resistance to abiotic and biotic stresses and cytoplasmic-male sterility for utilization in breeding programmes.

Seed Dormancy Variability in the U.S. Peanut Mini-Core Collection

2012 ◽  
Vol 5 (3) ◽  
pp. 84-95 ◽  
Author(s):  
M.L. Wang ◽  
C.Y. Chen ◽  
D.L. Pinnow ◽  
N.A. Barkley ◽  
R.N. Pittman ◽  
...  
Keyword(s):  
Seed Dormancy ◽  
Core Collection ◽  
Mini Core Collection ◽  
The U.S

Diagnosing stem diseases.

2021 ◽  
pp. 174-196
Author(s):  
Shou-Hua Wang
Keyword(s):  
Disease Management ◽  
Microscopic Examination ◽  
Stem Canker ◽  
Macrophomina Phaseolina ◽  
Crown Rot ◽  
Stem Rot ◽  
Pathogenicity Test ◽  
Disease Symptoms ◽  
Southern Blight ◽  
Athelia Rolfsii

Abstract This chapter provides information on diagnosis of stem diseases, including disease symptoms, visual and microscopic examination, isolation and colony observation, DNA-based identification, and pathogenicity test. Stem disease management are also discussed. Hemp diseases including hemp southern blight (Athelia rolfsii), hemp charcoal rot (Macrophomina phaseolina), hemp stem canker, stem rot and crown rot (Fusarium), hemp crown rot (Pythium) among others were used as models.

scholarly journals Evaluation of linkage disequilibrium, population structure, and genetic diversity in the U.S. peanut mini core collection

BMC Genomics ◽  
2019 ◽  
Vol 20 (1) ◽  
Author(s):  
Paul I. Otyama ◽  
Andrew Wilkey ◽  
Roshan Kulkarni ◽  
Teshale Assefa ◽  
Ye Chu ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Population Structure ◽  
Linkage Disequilibrium ◽  
Core Collection ◽  
Mini Core Collection ◽  
The U.S

scholarly journals Brown Stem Rot Resistance in Soybean Germ Plasm from Central China

Plant Disease ◽  
1997 ◽  
Vol 81 (8) ◽  
pp. 953-956 ◽  
Author(s):  
M. S. Bachman ◽  
C. D. Nickell ◽  
P. A. Stephens ◽  
A. D. Nickell
Keyword(s):  
Germplasm Collection ◽  
Central China ◽  
Stem Rot ◽  
Disease Assessment ◽  
Sources Of Resistance ◽  
University Of Illinois ◽  
Brown Stem Rot ◽  
Phialophora Gregata ◽  
Foliar Symptoms ◽  
Resistant Lines

Soybean accessions from China were screened in an attempt to identify unique sources of resistance to Phialophora gregata, the cause of brown stem rot. In 1994, over 500 accessions from the USDA Soybean Germplasm Collection, University of Illinois, Urbana-Champaign, were evaluated in the field at Urbana, IL, for reaction to brown stem rot. The accessions originated from nine provinces in central China and ranged in maturity from groups II to IV. Disease assessment was based on incidence of foliar symptoms and severity of stem symptoms produced by infection with natural inoculum. Based on field results, 64 putatively resistant lines were selected and evaluated in the greenhouse by a root-dip inoculation method. Thirteen accessions with levels of resistance equal to those of resistant standards were identified from five provinces. These lines may have value as donors of unique sources of resistance to brown stem rot.

Oil, Fatty Acid, Flavonoid, and Resveratrol Content Variability andFAD2AFunctional SNP Genotypes in the U.S. Peanut Mini-Core Collection

2013 ◽  
Vol 61 (11) ◽  
pp. 2875-2882 ◽  
Author(s):  
Ming Li Wang ◽  
Charles Y. Chen ◽  
Brandon Tonnis ◽  
Noelle A. Barkley ◽  
David L. Pinnow ◽  
...  
Keyword(s):  
Fatty Acid ◽  
Core Collection ◽  
Mini Core Collection ◽  
The U.S

Reaction of the Core Collection of Peanut Germplasm to Sclerotinia Blight and Pepper Spot1

2010 ◽  
Vol 37 (1) ◽  
pp. 1-11 ◽  
Author(s):  
J. P. Damicone ◽  
C. C. Holbrook ◽  
D. L. Smith ◽  
H. A. Melouk ◽  
K. D. Chamberlin
Keyword(s):  
Core Collection ◽  
Growth Habit ◽  
Disease Incidence ◽  
Germplasm Collection ◽  
Blight Resistance ◽  
Sources Of Resistance ◽  
Sclerotinia Blight ◽  
History Of ◽  
Growth Habits ◽  
Moderately Resistant

Abstract In 2001, entries from the peanut core collection, a subset of the USDA peanut germplasm collection, were planted in non-replicated plots in a field with a history of Sclerotinia blight caused by Sclerotinia minor. Variability existed among entries for reaction to Sclerotinia blight. Of the 744 entries evaluated, 11% had no disease, nearly 30% had <10% disease incidence, and only 21% had 50% disease incidence or more. Most of the resistant entries had an upright growth habit and were in early and mid-maturity groups. Many of the early maturing entries were susceptible to the foliar disease pepper spot which occurred throughout the study. Entries were selected for further evaluation in replicated plots based on a nil to low (<10%) incidence of Sclerotinia blight, adaptation and/or vigor, and other desirable characteristics such as an intermediate to prostrate growth habit and pepper spot resistance. Selected entries were retested in both 2002 and 2003 (n  =  62) and compared to resistant (Tamspan 90), moderately resistant (Tamrun 96), and susceptible (Okrun) reference cultivars. Most entries (55 in 2001 and 46 in 2003) had disease incidence less than Tamrun 96 and similar to Tamspan 90. In 2003 when disease incidence was highest, all 46 entries with resistant reactions similar to that of Tamspan 90 had erect plant growth habits except for entries 208 and 582 which were prostrate, and entries 273, 128, and 804 which were intermediate. Resistance to Sclerotinia blight and yield similar to Tamspan 90, plant habit, and/or reactions to pepper spot and web blotch were used to select the best entries. Entries 208, 128, 804, 582, and 273 combined resistance to Sclerotinia blight, pepper spot, and web blotch with less than erect growth habits. Entry 103 had good Sclerotinia blight resistance and yield, but an upright growth habit. Entry 92 had an upright growth habit and low yield, but good Sclerotinia blight resistance. Entries 92 and 103 had upright growth habits but were among the best entries for resistant to pepper spot and web blotch. Entries 426, 184, and 562 were upright and susceptible to pepper spot, but had resistance to web blotch and the best resistance to Sclerotinia blight. These entries appear to be useful sources of resistance to Sclerotinia blight for breeding programs and for increasing the probability of finding additional sources of resistance in clusters of germplasm identified within the entire USDA collection.

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