scholarly journals A Note on a Greenhouse Evaluation of Wild Arachis Species for Resistance to Athelia rolfsii

2021 ◽  
Author(s):  
Rebecca S. Bennett ◽  
Angie D. Harting ◽  
Charles E. Simpson ◽  
Shyamalrau P. Tallury ◽  
Austin B. Pickering ◽  
...  
Keyword(s):  
Mycelial Growth ◽  
Lesion Length ◽  
Sources Of Resistance ◽  
Arachis Species ◽  
Southern Blight ◽  
Soilborne Disease ◽  
Greenhouse Evaluation ◽  
Athelia Rolfsii ◽  
Cultivated Peanut ◽  
The One

Athelia rolfsii (Curzi) C.C. Tu & Kimbr. is the one of the most damaging pathogens of cultivated peanut, causing the soilborne disease known regionally as white mold, stem rot, or southern blight. Because the genetic base for cultivated peanut is narrow, wild Arachis species may possess novel sources of disease resistance. We evaluated 18 accessions representing 15 Arachis species ( batizocoi , benensis , cardenasii , correntina , cruziana , diogoi , duranensis , herzogii , hoehnei , kempff - mercadoi , kuhlmannii , microsperma , monticola , simpsonii , williamsii ) in the greenhouse for resistance to At. rolfsii . Assays were conducted on intact plants propagated from rooted cuttings inoculated with mycelial plugs, and lesion length and mycelial growth were measured at 4, 6, 10, and 12 days after inoculation. For lesion length, Arachis batizocoi (PI 468326 and PI 468327), and A. kuhlmannii PI 468159 were the most susceptible entries with a mean lesion length >50 mm at 12 days after inoculation. Arachis microsperma (PI 666096 and PI 674407) and A. diogoi PI 468354 had the shortest lesions with mean lengths ≤16 mm at 12 days after inoculation. Arachis cruziana PI 476003 and the two A. batizocoi PIs had the highest mean area under the disease progress curves (AUDPCs), and the lowest AUDPC was obtained from the A. microsperma PI 674407. Mycelial growth was correlated with lesion length in most species except A. monticola PI 497260 . These results may be useful to peanut geneticists seeking additional sources of resistance to Athelia rolfsii .

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.

scholarly journals Growth Chamber Assay for Evaluating Resistance to Athelia rolfsii

2020 ◽  
Vol 47 (1) ◽  
pp. 25-32 ◽  
Author(s):  
R.S. Bennett
Keyword(s):  
Sclerotium Rolfsii ◽  
Growth Chamber ◽  
Lesion Length ◽  
Mycelium Growth ◽  
Arachis Species ◽  
Resistant Cultivars ◽  
Athelia Rolfsii ◽  
Commercial Cultivars ◽  
Intermediate Resistance ◽  
Resistant Genotypes

ABSTRACT Planting resistant cultivars is most sustainable method for managing Athelia rolfsii (= Sclerotium rolfsii), one of the most damaging pathogens of peanut worldwide. However, evaluating germplasm for resistance in the field can be complicated by unfavorable environmental conditions, uneven distribution of sclerotia in soil, and difficulty in growing non-standard peanut genotypes such as wild species. Thus, a growth-chamber assay was used to screen for resistance to A. rolfsii in the laboratory. Thirteen peanut genotypes were used to test the assay: cultivars Georgia-03L, Georgia-12Y, Florida-07, Georgia-07W, Tamrun OL02, FloRun ‘107′, Georgia-06G, and U.S. mini-core accessions CC038 (PI 493581), CC041 (PI 493631), CC068 (PI 493880), CC384 (PI 155107), CC650 (PI 478819), and CC787 (PI 429420). Lesion length, as well as length of visible mycelium, on the main stem and a side stem were recorded at 4, 7, 10, and 13 days after inoculation. In general, patterns of lesion and mycelium growth were similar. The most resistant genotypes, Georgia-03L and CC650, had the smallest lesions and least mycelium growth. However, Georgia-12Y, one of the most resistant cultivars available today, appeared less resistant than Georgia-03L in the assay. Other commercial cultivars were intermediate in lesion and mycelium lengths. The most susceptible entries were CC038, CC041, and CC787. Despite limitations in discriminating among genotypes with intermediate resistance to A. rolfsii, these assays may be useful for pre-screening germplasm to identify physiologically resistant and highly susceptible entries, as well as for screening Arachis species that are difficult to grow in the field.

Flavor Profiles of Wild Species-Derived Peanut Breeding Lines

2008 ◽  
Vol 35 (2) ◽  
pp. 81-85 ◽  
Author(s):  
S. P. Tallury ◽  
H. E. Pattee ◽  
T. G. Isleib ◽  
H. T. Stalker
Keyword(s):  
Wild Species ◽  
Interspecific Hybrid ◽  
Diploid Species ◽  
Sensory Attributes ◽  
Sources Of Resistance ◽  
Breeding Programs ◽  
Breeding Lines ◽  
Arachis Hypogaea L ◽  
Cultivated Peanut ◽  
Important Quality

Abstract Several diploid wild species of the genus Arachis L. have been used as sources of resistance to common diseases of cultivated peanut (Arachis hypogaea L.). Because flavor is among the most important quality attributes for commercial acceptance of roasted peanuts, sensory attributes of interspecific hybrid derived breeding lines were evaluated to determine if transfer of disease resistance from wild species is associated with concomitant changes in flavor. Sixteen interspecific hybrid derivatives with five diploid species in their ancestries and the commercial flavor standard, NC 7 were evaluated for sensory quality. Significant variation among entries was found for the roasted peanut, sweet, and bitter sensory attributes, but not for the overall contrast between NC 7 and the wild species-derived breeding lines. The variation was either between two groups of wild species-derived breeding lines or within one or both groups. Introduction of disease and pest resistance traits from Arachis species did not result in degradation or improvement of the flavor profile. This suggests that flavor of wild species-derived germplasm will not prevent its use either as parents in peanut breeding programs or as cultivars.

scholarly journals Colletotrichum isolates related to Anthracnose of cashew trees in Brazil: morphological and molecular description using LSU rDNA sequences

2010 ◽  
Vol 53 (4) ◽  
pp. 741-752 ◽  
Author(s):  
Ana Maria Queijeiro Lopez ◽  
John Alexander Lucas
Keyword(s):  
Mycelial Growth ◽  
Host Plants ◽  
Large Subunit ◽  
Lsu Rdna ◽  
Rdna Sequences ◽  
D2 Domain ◽  
The One ◽  
High Degree ◽  
Molecular Description ◽  
28S Ribosomal Dna

Thirty six isolates of fungi obtained from anthracnose lesions of cashew and associated host plants in Brazil, were compared by their cultural, morphological and partial sequences of the 28S ribosomal DNA characters. They showed a high degree of cultural variability. The average mycelial growth rate on all tested media ranged from 10.2-13.3 mm/day between the isolates. Most of them produced perithecia (sterile and fertile) and some produced setae (sterile and fertile). All the isolates produced acervuli with predominantly cylindrical conidia (12.4-17.7 µmX 4.8-6.0 µm in width) with round ends, which became septate on germination, and produced unlobed or slightlylobed appressoria. Comparison of the D2 domain of the large subunit (LSU) rDNA sequences with those of other defined species of Colletotrichum and Glomerella grouped 35 of the isolates with known strains of C. gloeosporioides from different hosts (> 98.9% homology). The one exception (LARS 921) was identical to G. cingulata (LARS 238) from Vigna unguiculata.

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 Comparative Reaction of Camelina sativa to Sclerotinia sclerotiorum and Leptosphaeria maculans

Plant Disease ◽  
2019 ◽  
Vol 103 (11) ◽  
pp. 2884-2892 ◽  
Author(s):  
Maria I. Purnamasari ◽  
William Erskine ◽  
Janine S. Croser ◽  
Ming Pei You ◽  
Martin J. Barbetti
Keyword(s):  
Sclerotinia Sclerotiorum ◽  
Leptosphaeria Maculans ◽  
Resistance Breeding ◽  
Hypersensitive Reaction ◽  
Camelina Sativa ◽  
Lesion Length ◽  
Oilseed Crop ◽  
Sources Of Resistance ◽  
Stem Lesion ◽  
Stem Resistance

Sclerotinia sclerotiorum and Leptosphaeria maculans are two of the most important pathogens of many cruciferous crops. The reaction of 30 genotypes of Camelina sativa (false flax) was determined against both pathogens. C. sativa genotypes were inoculated at seedling and adult stages with two pathotypes of S. sclerotiorum, highly virulent MBRS-1 and less virulent WW-1. There were significant differences (P < 0.001) among genotypes, between pathotypes, and a significant interaction between genotypes and pathotypes in relation to percent cotyledon disease index (% CDI) and stem lesion length. Genotypes 370 (% CDI 20.5, stem lesion length 1.8 cm) and 253 (% CDI 24.8, stem lesion length 1.4 cm) not only consistently exhibited cotyledon and stem resistance, in contrast to susceptible genotype 2305 (% CDI 37.7, stem lesion length 7.2 cm), but their resistance was independent to S. sclerotiorum pathotype. A F5-recombinant inbred line population was developed from genotypes 370 × 2305 and responses characterized. Low broad-sense heritability indicated a complex pattern of inheritance of resistance to S. sclerotiorum. Six isolates of L. maculans, covering combinations of five different avirulent loci (i.e., five different races), were tested on C. sativa cotyledons across two experiments. There was a high level of resistance, with % CDI < 17, and including development of a hypersensitive reaction. This is the first report of variable reaction of C. sativa to different races of L. maculans and the first demonstrating comparative reactions of C. sativa to S. sclerotiorum and L. maculans. This study not only provides new understanding of these comparative resistances in C. sativa, but highlights their potential as new sources of resistance, both for crucifer disease-resistance breeding in general and to enable broader adoption of C. sativa as a more sustainable oilseed crop in its own right.

scholarly journals Evaluation of Sclerotinia Stem Rot Resistance in Oilseed Brassica napus Using a Petiole Inoculation Technique Under Greenhouse Conditions

Plant Disease ◽  
2004 ◽  
Vol 88 (9) ◽  
pp. 1033-1039 ◽  
Author(s):  
J. Zhao ◽  
A. J. Peltier ◽  
J. Meng ◽  
T. C. Osborn ◽  
C. R. Grau
Keyword(s):  
Brassica Napus ◽  
Germ Plasm ◽  
Evaluation Criteria ◽  
Lesion Length ◽  
Sclerotinia Stem Rot ◽  
Flowering Stage ◽  
Sources Of Resistance ◽  
Inoculation Technique ◽  
Spring Type ◽  
Canola Quality

A petiole inoculation technique was adapted for evaluating resistance of oilseed Brassica napus seedlings to Sclerotinia sclerotiorum. In the first of four experiments, four isolates of S. sclerotiorum were tested, two originating from soybean and two from B. napus. In all, 10 to 47 B. napus accessions were inoculated in the seedling stage and responses to isolates were evaluated using days to wilt (DW) and a lesion phenotype index (LP). There were no significant differences in virulence among the four isolates for DW and only slight differences for LP. However, significant differences (P < 0.0001) were observed among the B. napus accessions for DW and LP in this experiment and in subsequent experiments using one isolate. The responses of accessions were consistent among experiments and among evaluation criteria. Higher levels of resistance were found among winter-type than spring-type accessions, and among rapeseed-quality compared with canola-quality accessions. The most resistant accessions identified also were the most resistant when inoculated at the flowering stage. Terminal stems were inoculated immediately below the lowest flower and stem lesion length (SLL) was used to characterize the interaction phenotype of each accession. The petiole inoculation technique can be used successfully to differentiate oilseed B. napus germ plasm for response to S. sclerotiorum. This inoculation technique and the sources of resistance identified in this study may be used to determine inheritance resistance to S. sclerotiorum and for improving oilseed B. napus cultivars for resistance to this important pathogen.

scholarly journals Evaluation of Arachis Species and Interspecific Tetraploid Lines for Resistance to Aflatoxin Production by Aspergillus flavus

2004 ◽  
Vol 31 (2) ◽  
pp. 134-141 ◽  
Author(s):  
H. Q. Xue ◽  
T. G. Isleib ◽  
H. T. Stalker ◽  
G. A. Payne ◽  
G. OBrian
Keyword(s):  
Aspergillus Flavus ◽  
Insect Pests ◽  
Low Cost ◽  
Aflatoxin Production ◽  
Management Program ◽  
Aflatoxin Contamination ◽  
Sources Of Resistance ◽  
Resistant Parent ◽  
Arachis Species ◽  
Aflatoxin Accumulation

Abstract Anatoxins are carcinogenic and extremely toxic secondary metabolites produced primarily by two fungi, Aspergillus flavus Link ex Fries and A. parasiticus Speare. Elimination of aflatoxin contamination in peanut (Arachis hypogaea L.) is a high priority of the peanut industry. Resistant cultivars should be an effective and low-cost part of an integrated aflatoxin management program. To date, no cultivated peanut has been reported with stable high levels of resistance to aflatoxin production. Arachis species and interspecific tetraploid lines have been evaluated for resistance to several peanut diseases and insect pests, and highly resistant accessions have been reported. Seven accessions of A. cardenasii Krapov. and W.C. Gregory, 29 of A. duranensis Krapov. and W.C. Gregory, and 17 interspecific tetraploid lines derived from A. hypogaea × A. cardenasii were inoculated with A. flavus strain NRRL 3357 and analyzed for aflatoxin content after incubation. On average, A. duranensis and A. cardenasii accumulated significantly less aflatoxin than A. hypogaea checks. The mean difference between the two wild species was not significant. Arachis duranensis accessions PI 468319 (GKBSPSc 30073), PI 468200 (GKBSPSc 30064), and PI 262133 (GKP 10038 sl.); and A. cardenasii accessions PI 262141 (GKP 10017) and PI 475997 (KSSc 36018) had reduced levels of aflatoxin accumulation and should be valuable sources of resistance to aflatoxin contamination. Of the interspecific tetraploid lines, only GP-NC WS 2 supported aflatoxin production not significantly different from resistant parent A. cardenasii GKP 10017, and it appears to be a line with reduced capacity for aflatoxin accumulation.

scholarly journals Mycelial inhibition of Trichoderma spp. isolated from the cultivation of Pleurotus ostreatus with an extract of Pycnoporus sp.

2020 ◽  
Author(s):  
Anaid Talavera-Ortiz ◽  
Priscila Chaverri ◽  
Gerardo Diaz-Godinez ◽  
Ma de Lourdes Acosta-Urdapilleta ◽  
Elba Villegas ◽  
...  
Keyword(s):  
Growth Rate ◽  
Pleurotus Ostreatus ◽  
Mycelial Growth ◽  
Viral Diseases ◽  
Human Consumption ◽  
Edible Fungi ◽  
Lignocellulosic Substrate ◽  
Trichoderma Spp ◽  
Mycelial Growth Rate ◽  
The One

Abstract:Background and Aims: The production of edible fungi is affected by bacterial, fungal and viral diseases, which very often cause large losses. In the productionof mushrooms of the genus Pleurotus, the fungi of Trichoderma spp. represent a serious problem of contamination and although there are some chemical compoundsthat control the infection, they are not entirely safe for human consumption. As a consequence, alternatives are being searched for through biotechnology,such as the one presented in this paper.Methods: Strains of fungi of the genus Trichoderma were isolated from the substrate where Pleurotus ostreatus was being cultivated. These were identifiedmorphologically and molecularly, followed by tests to inhibit the growth of Trichoderma strains in both agar and wheat straw, using a cetonic extract of thedehydrated fruiting body of Pycnoporus sp.Key results: Two strains of Trichoderma (T. pleuroti and T. atrobrunneum, belonging to the clade of T. harzianum) were isolated from infected substrate obtainedin production modules of Pleurotus ostreatus located in Tlaquitenango and Cuernavaca, in the state of Morelos, Mexico. The effect of a cetonic extract of thefruiting body of Pycnoporus sp. on the mycelial growth of the isolated strains of Trichoderma was also evaluated, observing decrease in mycelial growth rate inPetri dish up to 72% and on lignocellulosic substrate both mycelial growth and sporulation were delayed up to 10 days.Conclusions: The extract of Pycnoporus sp. could be an alternative to control the infection by Trichoderma spp. in mushroom cultures of the genus Pleurotus.Key words: disease control, edible mushrooms, lignocellulosic substrate. 

Sign in / Sign up

Export Citation Format

Share Document