Comparative assessments of seedling runner and adult-plant resistance to leaf scorch in strawberry

Nine progeny populations, derived from a half-diallel and self-crosses of strawberry cultivars Vantage, Scotland, Governor Simcoe and Kent were evaluated for resistance to leaf scorch (Diplocarpon earlianum) as seedling runners and at the adult-plant stage. At both stages selfed Vantage and selfed Scotland were resistant; crosses between Vantage and Kent and between Governor Simcoe and Kent were susceptible; and remaining progeny populations were of intermediate resistance. A strong correlation (r = 0.970, P < 0.01) was observed between resistance of seedling runners and adult-plants of the nine S1 and F1 populations. The results suggest that strawberry genotypes can be evaluated effectively at the seedling stage in a breeding program for resistance to leaf scorch. Key words: Leaf scorch, Diplocarpon earlianum, strawberry, Fragaria × ananassa, seedling-runner, adult plant, resistance

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Deciphering resistance to Zymoseptoria tritici in the Tunisian durum wheat landrace accession ‘Agili39’

10.21203/rs.3.rs-923215/v1 ◽

2021 ◽

Author(s):

Sahbi Ferjaoui ◽

Lamia Aouini ◽

Rim Ben Slimane ◽

Karim Ammar ◽

Suzanne Dreisigacker ◽

...

Keyword(s):

Durum Wheat ◽

Plant Resistance ◽

Adult Plant Resistance ◽

Field Trials ◽

Adult Plant ◽

Zymoseptoria Tritici ◽

Adult Plant Stage ◽

Plant Stage ◽

Explained Variance ◽

Major Qtl

Abstract Background Septoria tritici blotch (STB), caused by Zymoseptoria tritici (Z. tritici), is an important biotic threat to durum wheat in the entire Mediterranean Basin. Although most durum wheat cultivars are susceptible to Z. tritici, research in STB resistance in durum wheat has been limited. Results In our study, we have identified resistance to a wide array of Z. tritici isolates in the Tunisian durum wheat landrace accession ‘Agili39’. Subsequently, a recombinant inbred population was developed and tested under greenhouse conditions at the seedling stage with eight Z. tritici isolates and for five years under field conditions with three Z. tritici isolates. Mapping of quantitative trait loci (QTL) resulted in the identification of two major QTL on chromosome 2B designated as Qstb2B_1 and Qstb2B_2. The Qstb2B_1 QTL was mapped at the seedling and the adult plant stage (highest LOD 33.9, explained variance 61.6 %), conferring an effective resistance against five Z. tritici isolates. The Qstb2B_2 conferred adult plant resistance (highest LOD 32.9, explained variance 42 %) and has been effective at the field trials against two Z. tritici isolates. The Qstb2B_1 QTL was mapped at the seedling and the adult plant stage (highest LOD 33.9, explained variance 61.6 %), conferring an effective resistance against five Z. tritici isolates. The Qstb2B_2 conferred adult plant resistance (highest LOD 32.9, explained variance 42 %) and has been effective at the field trials against two Z. tritici. The physical positions of the flanking markers linked to Qstb2B_1 and Qstb2B_2 indicate that these two QTL are 5Mb apart. In addition, we identified two minor QTL on chromosomes 1A (Qstb1A) and chromosome 7A (Qstb7A) (highest LODs 4.6 and 4.0, and explained variances of 16 % and 9%, respectively) that were specific to three and one Z. tritici isolates, respectively. All identified QTL were derived from the landrace accession Agili39 that represents a valuable source for STB resistance in durum wheat. Conclusion This study demonstrates that Z. tritici resistance in the ‘Agili39’ landrace accession is controlled by two minor and two major QTL acting in an additive mode.

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ADULT PLANT RESISTANCE OF SOME OAT VARIETIES TO PHYSIOLOGIC RACES OF CROWN RUST

Canadian Journal of Research ◽

10.1139/cjr44c-025 ◽

1944 ◽

Vol 22c (6) ◽

pp. 287-289 ◽

Cited By ~ 6

Author(s):

B. Peturson

Keyword(s):

Plant Resistance ◽

Adult Plant Resistance ◽

Crown Rust ◽

Seedling Stage ◽

Puccinia Coronata ◽

Adult Plant ◽

Adult Plant Stage ◽

Plant Stage ◽

Physiologic Races ◽

Generalized Type

The reactions of five varieties of oats in the seedling and adult plant stages to seven physiologic races of crown rust, Puccinia coronata Corda var. Avenae Erikss. & Henn. were determined.All five varieties were completely susceptible in the seedling stage to all the races. Two varieties, Erban and Ajax, were resistant in the adult plant stage to some of the races and susceptible or moderately susceptible to others. Two other varieties, R.L. No. 1370 and R.L. No. 1510 were resistant in the adult plant stage to all the races used in this test, and apparently possess a generalized type of adult plant resistance to crown rust.

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Adult plant resistance to white rust in Lunaria annua

Phytopathologia Mediterranea ◽

10.36253/phyto-12805 ◽

2021 ◽

Vol 60 (2) ◽

pp. 381-385

Author(s):

Diana CERVANTES ◽

Mary RIDOUT ◽

Claudia NISCHWITZ ◽

George NEWCOMBE

Keyword(s):

Plant Resistance ◽

Adult Plant Resistance ◽

Asymptomatic Infection ◽

Wild Plants ◽

Adult Plant ◽

Mature Adult ◽

White Rust ◽

Premature Deaths ◽

Introduced Range ◽

Adult Plants

Wild plants produce abundant seeds and seedlings, but most die before reaching maturity, and these premature deaths are often caused by pathogens. Major genes for resistance protect some seedlings or juveniles. These selected individuals can become a resistant, mature cohort. Alternatively, plants can exhibit mature, adult plant resistance. These two explanations can be indistinguishable in the field, when epidemics in natural pathosystems occur regularly resulting in annual selection for resistance. This study included multi-year observations of a biennial plant where the distinction could be made. White rust of Lunaria annua, a pathosystem native to the Mediterranean Basin, took time in its introduced range in Idaho, USA, to generate epidemics. After years of minimal white rust, an epidemic occurred in 2017 in which first-year, juvenile plants had 20 times the sorus density of second-year, adult plants. Since white rust incidence had been minimal for years prior to 2017, the greater resistance of 2017 adults over 2017 juveniles may have been due to adult-plant resistance. This could also be due to phenology: adult plants have mature leaves, and are flowering and maturing seed, by the time that white rust begins to build up on leaves of juveniles. The juvenile-adult difference was maintained in 2018. In white blister rusts, interpretation of resistance can also be complicated by the frequency of asymptomatic infections that adult plants would pass on to the next generation. However, we found no asymptomatic infection of seeds of L. annua in our sampling of the Idaho population.

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THE INHERITANCE OF RESISTANCE TO STEM RUST RACES 56 AND 15B-1L (CAN.) IN THE WHEAT VARIETIES HOPE AND H-44

Canadian Journal of Genetics and Cytology ◽

10.1139/g68-043 ◽

1968 ◽

Vol 10 (2) ◽

pp. 311-320 ◽

Cited By ~ 21

Author(s):

D. R. Knott

Keyword(s):

Adult Plant Resistance ◽

Recessive Gene ◽

Adult Plant ◽

Inheritance Of Resistance ◽

Single Recessive Gene ◽

Wheat Varieties ◽

Adult Plant Stage ◽

Plant Stage ◽

Physiological Resistance ◽

Dominant Genes

The inheritance of resistance to races 56 and 15B-1L was studied in back-crosses of Hope and H-44 to Marquis. The results indicated that both varieties carry the same three genes. Resistance to race 56 is controlled by two dominant genes, Sr 1 which conditions seedling or physiological resistance and Sr 2 which conditions adult plant resistance. At either the seedling or adult plant stage both genes must be present to provide full resistance to race 56. A single recessive gene, not yet named, provides resistance to race 15B-1L.The gene Sr 1 was transferred from Hope to Marquis by backcrossing and the line was crossed to the Chinese Spring monosomics. The gene proved to be on chromosome 2B (XIII).

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Race-Specific Adult-Plant Resistance in Winter Wheat to Stripe Rust and Characterization of Pathogen Virulence Patterns

Phytopathology ◽

10.1094/phyto-11-14-0305-r ◽

2015 ◽

Vol 105 (8) ◽

pp. 1114-1122 ◽

Cited By ~ 12

Author(s):

Eugene A. Milus ◽

David E. Moon ◽

Kevin D. Lee ◽

R. Esten Mason

Keyword(s):

United States ◽

Winter Wheat ◽

Stripe Rust ◽

Plant Resistance ◽

Rust Resistance ◽

Adult Plant Resistance ◽

Stripe Rust Resistance ◽

Adult Plant ◽

Pathogen Population ◽

Adult Plants

Stripe rust, caused by Puccinia striiformis f. sp. tritici, is an important disease of wheat in the Great Plains and southeastern United States. Growing resistant cultivars is the preferred means for managing stripe rust, but new virulence in the pathogen population overcomes some of the resistance. The objectives of this study were to characterize the stripe rust resistance in contemporary soft and hard red winter wheat cultivars, to characterize the virulence of P. striiformis f. sp. tritici isolates based on the resistances found in the cultivars, and to determine wheat breeders’ perceptions on the importance and methods for achieving stripe rust resistance. Seedlings of cultivars were susceptible to recent isolates, indicating they lacked effective all-stage resistance. However, adult-plants were resistant or susceptible depending on the isolate, indicating they had race-specific adult-plant resistance. Using isolates collected from 1990 to 2013, six major virulence patterns were identified on adult plants of twelve cultivars that were selected as adult-plant differentials. Race-specific adult-plant resistance appears to be the only effective type of resistance protecting wheat from stripe rust in eastern United States. Among wheat breeders, the importance of incorporating stripe rust resistance into cultivars ranged from high to low depending on the frequency of epidemics in their region, and most sources of stripe rust resistance were either unknown or already overcome by virulence in the pathogen population. Breeders with a high priority for stripe rust resistance made most of their selections based on adult-plant reactions in the field, whereas breeders with a low priority for resistance based selections on molecular markers for major all-stage resistance genes.

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Molecular characterization of adult plant resistance loci against powdery mildew in winter wheat cultivar Liangxing 99 using BSR-Seq technology

Plant Disease ◽

10.1094/pdis-03-21-0664-re ◽

2021 ◽

Author(s):

Xiaohan Shi ◽

Peipei Wu ◽

Jinghuang Hu ◽

Dan Qiu ◽

Yunfeng Qu ◽

...

Keyword(s):

Powdery Mildew ◽

Winter Wheat ◽

Plant Resistance ◽

Adult Plant Resistance ◽

Wheat Cultivar ◽

Field Tests ◽

Blumeria Graminis ◽

Adult Plant ◽

Winter Wheat Cultivar ◽

Plant Stage

Winter wheat cultivar Liangxing 99, which carries gene Pm52, is resistant to powdery mildew at both seedling and adult plant stages. An F2:6 recombinant inbred line (RIL) population from cross Liangxing 99 × Zhongzuo 9504 was phenotyped with Blumeria graminis f. sp. tritici isolate Bgt27 at the adult plant stage in four field tests and the seedling stage in a greenhouse test. The analysis of bulk segregant RNA sequences identified an SNP-enriched locus, Qaprpm.caas.2B, on chromosome 2BL in the same genomic interval of Pm52 associated with the all-stage resistance (ASR) and Qaprpm.caas.7A on chromosome 7AL associated with the adult-plant resistance (APR) against the disease. Qaprpm.caas.2B was detected in a 1.3 cM genetic interval between markers Xicscl726 and XicsK128 in which Pm52 was placed with a range of LOD values from 28.1 to 34.6, and the phenotype variations explained in terms of maximum disease severity (MDS) ranged from 45% to 52%. The LOD peak of Qaprpm.caas.7A was localized in a 4.6 cM interval between markers XicsK7A8 and XicsK7A26 and explained the phenotypic variation of MDS ranging from 13% to 16%. The results of this study confirmed Pm52 for ASR and identified Qaprpm.caas.7A for APR to powdery mildew in Liangxing 99. Keywords: Triticum aestivum; Blumeria graminis f. sp. tritici; Pm52; QTL; BSR-Seq

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Seedling and adult plant resistance to Pyricularia oryzae in Ethiopian rice cultivars

Acta Universitatis Sapientiae Agriculture and Environment ◽

10.2478/ausae-2020-0004 ◽

2020 ◽

Vol 12 (1) ◽

pp. 45-57

Author(s):

Geleta Gerema ◽

Girma Mengistu ◽

Megersa Kebede ◽

Dagnachew Lule ◽

Kebede Desalegn ◽

...

Keyword(s):

Plant Resistance ◽

Adult Plant Resistance ◽

Blast Resistance ◽

Yield Reduction ◽

Adult Plant ◽

Rice Cultivars ◽

Rice Varieties ◽

Plant Stage ◽

Rice Improvement ◽

High Level

AbstractTwo separate experiments were done for seedling and adult resistance in rice varieties against blast. Each experiment consists of 20 varieties and is evaluated under artificial inoculation with blast. The result of the study confirmed that NERICA varieties have shown low disease infection at the seedling stage whereas the varieties Chewaka and Edget have shown adult plant resistance. Severe yield reduction and highly diseased grain were obtained from Superica-1, which is highly susceptible at adult plant stage. In contrast, the maximum grain yield was obtained from the Chewaka and Edget varieties, these having a high level of adult resistance. Therefore, Chewaka and Edget are promising candidates for utilization in yield and blast resistance in rice improvement.

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