New sources of resistance in Trifolium subterraneum L. to root rot caused by two races of Phytophthora clandestina Taylor, Pascoe and Greenhalgh

2005 ◽  
Vol 56 (3) ◽  
pp. 271 ◽  
Author(s):  
M. P. You ◽  
M. J. Barbetti ◽  
P. G. H. Nichols
Keyword(s):  
Root Rot ◽  
Trifolium Subterraneum ◽  
Sources Of Resistance ◽  
Breeding Programs ◽  
Breeding Lines ◽  
Late Flowering ◽  
Group 12 ◽  
New Cultivars

Eighty-four genotypes, comprising 71 ssp. subterraneum and ssp. yanninicum breeding lines of Trifolium subterraneum and 13 cultivars commonly used at the time of commencement of the experiment, were screened in the glasshouse for resistance to root rot caused by 2 races of Phytophthora clandestina that occur most widely in Australia. Resistance to race coded 001 was identified in 7 mid-season genotypes of ssp. subterraneum, including the new cultivar, Coolamon, and one genotype also showed resistance to race coded 373. Of the late flowering ssp. subterraneum genotypes tested, 13 showed resistance to race coded 001 and 4 of them also showed resistance to race coded 373. In the late flowering ssp. yanninicum group, 12 of 13 genotypes tested, including the new cultivar, Napier, showed resistance to both races. Of the mid-season ssp. yanninicum genotypes, all but 2 of 19 tested showed resistance to both races. The resistance observed in the majority of ssp. yanninicum and in some ssp. suberraneum genotypes, indicates that these are useful sources of resistance that can be exploited, either directly as new cultivars to minimise damage from this disease, or as parents in breeding programs to develop cultivars with improved resistance to P. clandestina. This study established the availability of 51 advanced lines and 11 cultivars as sources of resistance against P. clandestina race coded 001 and 36 lines and 4 cultivars for race coded 373, among which 36 lines and 4 cultivars were resistant against both races.

scholarly journals Identification of Pisum sativum Germ Plasm with Resistance to Root Rot Caused by Multiple Strains of Aphanomyces euteiches

Plant Disease ◽  
1999 ◽  
Vol 83 (1) ◽  
pp. 51-54 ◽  
Author(s):  
D. K. Malvick ◽  
J. A. Percich
Keyword(s):  
Pisum Sativum ◽  
Root Rot ◽  
Plant Introduction ◽  
Aphanomyces Euteiches ◽  
Sources Of Resistance ◽  
Breeding Programs ◽  
Pea Seedlings ◽  
Biomass Loss ◽  
Serious Disease ◽  
Multiple Strains

Aphanomyces root rot is a serious disease of pea (Pisum sativum), and additional sources of resistance are needed for development of disease-resistant cultivars. Accessions (n = 123) from the P. sativum Plant Introduction (PI) collection with the highest relative levels of resistance to one strain of Aphanomyces euteiches were previously identified from among approximately 2,500 accessions evaluated. The chosen 123 accessions were evaluated in this study for resistance to root rot caused by multiple strains of this pathogen. Five strains representing different US geographical locations and pathogenicity characteristics were used to evaluate pea seedlings in a greenhouse. Disease severity (DS) and percent loss of fresh biomass (inoculated vs. non-inoculated plants) were determined 15 days after inoculation. Significant differences (P = 0.05) in levels of DS and biomass loss (BL) occurred among the accessions after inoculation individually with the five strains. The relative rank of accessions based on DS and BL varied with the strain of A. euteiches used for inoculations. The 20 accessions with the lowest DS after inoculation with each strain were identified. Based on lowest DS, two accessions were among the 20 identified with all five individual strains, and four other accessions were among the 20 identified with four of the five strains. The results suggest that the P. sativum PI collection contains useful accessions for breeding programs aimed at developing pea varieties with resistance to A. euteiches.

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.

The proportion of individual lucerne plants resistant to Phytophthora medicaginis and Colletotrichum trifolii in Australian cultivars

1998 ◽  
Vol 38 (1) ◽  
pp. 41 ◽  
Author(s):  
J. M. Mackie ◽  
J. A. G. Irwin
Keyword(s):  
Root Rot ◽  
Crown Rot ◽  
Sources Of Resistance ◽  
Breeding Programs ◽  
Phytophthora Root Rot ◽  
Colletotrichum Trifolii ◽  
Eastern Australia

Summary. Phytophthora root rot (Phytophthora medicaginis) and colletotrichum crown rot (Colletotrichum trifolii) are the 2 most serious pathogens of lucerne in eastern Australia. Work reported in this paper shows that in glasshouse tests of the 11 most commonly grown Australian lucerne cultivars, the proportion of individual plants with resistance to both pathogens ranges from 0 (Hunter River and Aurora) through to a maximum of 19.8% (Sequel HR). Within 9 of the cultivars, the proportion of individual plants resistant to the 2 pathogens was <7%. Since these 2 diseases are known to cause serious losses in eastern Australia, the results indicate further improvement in lucerne production can be obtained by increasing the proportion of individual plants in a cultivar resistant to both pathogens. This would be best achieved by identifying dominant sources of resistance and incorporating this into on-going lucerne breeding programs.

Allelic studies of new sources of scald (Rhynchosporium secalis Davis) resistance in barley

2003 ◽  
Vol 83 (4) ◽  
pp. 709-713 ◽  
Author(s):  
A. K. Singh ◽  
G. J. Scoles ◽  
R. A. Pickering ◽  
B. G. Rossnagel
Keyword(s):  
New Zealand ◽  
Genetic Resistance ◽  
Rhynchosporium Secalis ◽  
Sources Of Resistance ◽  
Hordeum Vulgare L ◽  
Breeding Programs ◽  
Breeding Lines ◽  
Disease Management Strategy ◽  
Key Words Barley ◽  
Resistant Lines

The use of genetic resistance is a desirable disease management strategy for controlling scald (Rhynchosporium secalis Davis) in barley (Hordeum vulgare L.); thus, it is essential to screen for new sources of resistance. The objectives of this study were to test the novelty of scald resistance in two barley lines from New Zealand, 145L2 and 4176/10/n/3/2/6, relative to a number of resistance sources available to western Canadian breeding programs, and to determine the source of this resistance. 145L2 and 4176/10/n/3/2/6 were resistant in New Zealand and in scald screening nurseries in Alberta, Canada, in 1998. 145L2 was crossed with 4176/10/n/3/2/6 and with four local resistant lines to determine allelic relationships between 145L2 resistance, 4176/10/n/3/2/6 resistance and the resistance(s) in the local lines. To determine the source of the resistance, all H. vulgare L. lines in the pedigree of the New Zealand lines were evaluated in the same nurseries. The resistance gene in 145L2 was not allelic to that in 4176/10/n/3/2/6 or the other barley lines tested. All lines in the pedigree of the two New Zealand lines were susceptible, suggesting that their resistance is derived from unknown parents in their pedigrees. These New Zealand lines provide new sources of scald resistance that can be incorporated into western Canadian breeding lines. Key words: Barley, scald, resistance

Reactions of eastern Canada oat genotypes to Puccinia coronata f. sp. avenae

2020 ◽  
Vol 100 (2) ◽  
pp. 209-217
Author(s):  
Allen G. Xue ◽  
Jim Menzies ◽  
Yuanhong Chen ◽  
Weikai Yan ◽  
Bao-luo Ma ◽  
...  
Keyword(s):  
Natural Populations ◽  
Field Trials ◽  
Crown Rust ◽  
Puccinia Coronata ◽  
Adult Plant ◽  
Limiting Factor ◽  
Sources Of Resistance ◽  
Eastern Canada ◽  
Breeding Programs ◽  
Breeding Lines

Crown rust, caused by Puccinia coronata f. sp. avenae (Pca), is the most important disease and yield limiting factor of oat production in eastern Canada. In this study 101 oat genotypes composed of 51 cultivars and 50 breeding lines from eight oat breeding programs across Canada were evaluated for seedling reactions to six common Pca races, as well as reactions to a bulk inoculum of Pca in greenhouse trials and for adult plant resistance (APR) to natural populations of Pca in field trials in 2014 and 2015. Sixty-six genotypes showed resistant reactions to at least one of the six races; of these, 22 were resistant to all six races. These 22 genotypes also showed resistance to the bulk inoculum at the seeding stage and to the natural populations of Pca at the adult plant stage, suggesting that these current and future oat varieties have effective resistance against the common races and Pca populations in the region. Eleven genotypes, including 12ANS03, AAC Bullet, CFA1213, CFA1306, Idaho, OA1301-1w-3, OA1369-5, OA1370-2, OA1371-2, OA1383-2, and Oscar, were susceptible as seedlings but resistant as adult plants. APR is proven to be long lasting and provides broad-spectrum resistance to Pca populations. The 11 oat genotypes identified with APR in the present study are more desirable as sources of resistance for breeding programs developing durable crown rust resistant cultivars for eastern Canada.

Screening Exotic Sorghum Germplasm, Hybrids, and Elite Lines for Resistance to a New Virulent Pathotype (P6) of Peronosclerospora sorghi Causing Downy Mildew

2011 ◽  
Vol 12 (1) ◽  
pp. 17 ◽  
Author(s):  
Ghada L. Radwan ◽  
Ramasamy Perumal ◽  
Thomas Isakeit ◽  
Clint W. Magill ◽  
Louis K. Prom ◽  
...  
Keyword(s):  
Downy Mildew ◽  
Single Gene ◽  
Successful Management ◽  
Sources Of Resistance ◽  
Causal Organism ◽  
Breeding Programs ◽  
Breeding Lines ◽  
Peronosclerospora Sorghi ◽  
Recent Outbreak ◽  
Elite Breeding Lines

A recent outbreak of sorghum downy mildew (SDM) in Texas has led to the discovery of both metalaxyl fungicide resistance and a new pathotype, P6, in the causal organism Peronosclerospora sorghi. New and alternate sources of host plant resistance are needed for successful management of SDM. To identify sources of resistance, a total of 333 (242 minicore lines representing diverse germplasm from India, 67 commercial hybrids from Kansas, and 24 elite breeding lines from Texas) were inoculated in the greenhouse. Using an established sandwich inoculation technique, artificial inoculation of test lines with P. sorghi conidia, resulting in < 10% infection, were scored as “resistant.” Fifty-two minicore and 20 accessions from Kansas exhibited ≤ 10% infection and were selected as resistant. Out of 52 resistant minicore accessions, 28 were photoinsensitive. Eleven of 20 commercial hybrids from Kansas showed zero percent infection. Thirteen of 24 elite breeding lines from Texas were also resistant. In this study, resistance sources for the new P6 SDM pathotype were identified. The diversity among these materials is expected to provide different single-gene sources as well as quantitative sources of SDM resistance for use in breeding programs. Accepted for publication 13 January 2011. Published 23 March 2011.

scholarly journals Identification of sources of winter barley resistance to smut (Ustilago hordei)

2020 ◽  
pp. 72-76
Author(s):  
N. V. Shishkin ◽  
T. G. Derova ◽  
E. S. Doroshenko ◽  
O. S. Pavlenko
Keyword(s):  
Winter Barley ◽  
Optimal Time ◽  
Artificial Infection ◽  
Good Resistance ◽  
Sources Of Resistance ◽  
Breeding Programs ◽  
Breeding Lines ◽  
Resistant Varieties ◽  
Ustilago Hordei ◽  
Barley Resistance

The current paper presents the 3-year assessment results of domestic and foreign winter barley varieties and lines for smut resistance. The smut pathogen in the Rostov region causes one of the most harmful diseases, which, in addition to direct crop losses (head destruction), causes the so-called hidden losses, which can several times exceed direct ones. An effective way to counteract the disease is to cultivate resistant varieties, and farmers need the reliable sources of resistance to the pathogen. The immunological properties of winter barley varieties were studied in an infectious nursery (2016–2018). Seed infection with spores was carried out by S. Dimitrov’s method (1968) using a nutrient medium. Inoculated seeds were sown at the end of the optimal time. There was estimated a number of infected stems. The variety “Dobrynya 3” was used as a susceptible test-variety, which percentage of infection throughout the years ranged from 20.6 to 71.8%. There were studied 115 domestic and foreign varieties and lines. Among 69 domestic commercial varieties and breeding lines, 11 ones (15.9%) showed good resistance, 21 ones (30.4%) showed weak susceptibility, 30 ones (43.5%) possessed average susceptibility and seven varieties (10.1%) were severely affected by the pathogen. Among foreign varieties, resistance to barley smut has been established in seven German varieties, in three French varieties, in two Swiss varieties, one Czech variety and one Ukrainian variety. The varieties “Rocca”, “Nixe” (Germany), “Metelitsa” (Ukraine) are classified as the best ones in resistance to the pathogen during the artificial infection. The French variety “18513 ЕН11” had no affected plants during the study and was identified as an immune variety. The identified sources of winter barley resistance to smut are recommended for use in breeding programs for immunity.

Response of Italian elite subterranean clover genotypes to Fusarium avenaceum and Fusarium oxysporum under artificial conditions

2002 ◽  
Vol 42 (5) ◽  
pp. 557 ◽  
Author(s):  
E. Piano ◽  
L. Riccioni ◽  
L. Pecetti ◽  
A. M. Carroni ◽  
A. Porta-Puglia
Keyword(s):  
Root Rot ◽  
Disease Outbreaks ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Fusarium Spp ◽  
Seedling Vigour ◽  
Breeding Programs ◽  
Disease Response ◽  
Artificial Infestation ◽  
Growth Vigour

Breeding programs of subterranean clover in southern Europe have traditionally set low priority on selection against major pathogens, in part because there have been no major disease outbreaks in this region. However, root-rot causing fungi, such as Fusarium spp., occur frequently on other crops and can therefore also represent a threat to clover. Thus, the breeding program carried out in Sardinia, Italy, took note of this disease. This study reports the results of 2 trials carried out in 2 consecutive years following artificial infestation with Fusarium spp. The first trial included 45 genotypes, of which 37 were Sardinian lines under advanced breeding and 8 were commercial varieties. To validate the variation observed in disease response, a subset of 27 genotypes was further evaluated in the second trial. In both trials, 3 pathogen treatments were applied, in addition to a control, uninoculated treatment - F. avenaceum, F. oxysporum, and an equal mixture of both fungi. One-month-old clover seedlings were scored in all treatments for shoot-growth vigour (1-9 scale), then excavated for scoring root-rot symptoms (1-5�scale), and finally weighed after oven drying. Analysis of variance tested differences among treatments, among genotypes, and between subsp. subterraneum and brachycalycinum of Trifolium subterraneum. On the common set of genotypes to both trials, a cluster analysis was applied using, as original variables, the average disease score across the 3 inoculated treatments in the 2 trials. Confirming previous evidence, F. avenaceum proved more pathogenic than F. oxysporum. The results suggested that high seedling vigour may play a role in limiting root-rot effects, and this may also contribute to the relatively better tolerance of subsp. brachycalycinum over subsp. subterraneum observed. Despite some inconsistency of response in the 2 trials both at the treatment and genotype level, some Sardinian genotypes demonstrated a consistent level of tolerance especially in relation to the performance of the commercial varieties tested. Among them were the lines `125 brachy C', `56 sub D', `22 brachy G', `56 sub B' (=Campeda), and `19 brachy E' (=Antas).

Biplot evaluation of test environments and identification of lentil genotypes with durable resistance to fusarium wilt in India

2017 ◽  
Vol 68 (11) ◽  
pp. 1024 ◽  
Author(s):  
A. K. Parihar ◽  
Ashwani K. Basandrai ◽  
D. R. Saxena ◽  
K. P. S. Kushwaha ◽  
S. Chandra ◽  
...  
Keyword(s):  
Fusarium Wilt ◽  
Disease Incidence ◽  
Durable Resistance ◽  
Sources Of Resistance ◽  
Breeding Programs ◽  
Breeding Lines ◽  
Disease Occurrence ◽  
Sources Of Variation ◽  
Testing Site ◽  
Natural Incidence

Fusarium wilt (caused by Fusarium oxysporum f. sp. lentis) is the most crucial limiting variable for decreasing yield levels of lentils (Lens culinaris Medik.) around the world. A set of 20 diverse lentil genotypes comprising breeding lines and released varieties was evaluated, along with susceptible controls, for resistance to fusarium wilt through natural incidence for two continuous years (2010–11 and 2011–12) in six diverse lentil-growing environments in India. Analysis of variance showed that the effect of genotype (G) and environment (E) for disease incidence was highly significant. Among the three sources of variation, the biggest contribution in disease occurrence was accounted for by environment (54.68%), followed by G × E interaction (17.32%). The high G × E variation necessitated assessment of the genotypes at different locations (environments). GGE biplot analysis of the studied genotypes revealed that genotype PL 101 and released cultivar L 4076 had low levels of disease incidence. The sources of resistance to fusarium wilt have great potential for use in lentil-breeding programs. Another biplot of relationships among environments demonstrated that, among the test locations, Sehore and Faizabad, were the most effective for differentiation of genotypes. On the basis of discriminating ability and representativeness, the Sehore location appeared an ideal testing site for natural incidence of F. oxysporum f. sp. lentis.

scholarly journals Sources of Resistance to Powdery Mildew in Barley Landraces from Turkey

Agriculture ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1017
Author(s):  
Jerzy H. Czembor ◽  
Elżbieta Czembor
Keyword(s):  
Powdery Mildew ◽  
Resistance Genes ◽  
Sources Of Resistance ◽  
Seedling Resistance ◽  
Breeding Programs ◽  
Breeding Lines ◽  
Resistant Lines ◽  
Highly Effective ◽  
Barley Landraces

Powdery mildew on barley, caused by the pathogen Blumeria graminis f. sp. hordei, occurs worldwide and can result in severe yield loss. Germplasm of barley, including landraces, commercial cultivars, wild relatives and breeding lines are stored in more than 200 institutions. There is a need for characterization of this germplasm in terms of resistance to biotic and abiotic stresses. This is necessary in order to use specific accessions in breeding programs. In the present study, 129 barley landraces originated from Turkey and provided by the ICARDA genebank were tested for resistance to powdery mildew. Seedling resistance tests after inoculation with 19 differentiated isolates of B. graminis f. sp. hordei were used to postulate the presence of resistance genes. From the 129 landraces studied, plants of 19 (14.7%) of them showed resistance to infection with powdery mildew. Based on preliminary tests from these 19 landraces, 25 resistant single plant lines were selected for testing with differential powdery mildew isolates. Seven lines were resistant to all 19 isolates used. However, only one line (5583-1-4) showed resistance scores of zero against all isolates used. It is likely that this line possesses unknown, but highly effective genes for resistance. In five resistant lines it was not possible to postulate the presence of specific resistance genes. In 19 lines the presence of the genes Mlp, Mlk, Mlh, Mlg, Ml(CP), Mlat, Mla3, Mla6, Mla7 and Mla22 were postulated. These new sources of highly effective powdery mildew resistance in barley landraces from Turkey could be successfully used in breeding programs.

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