A GENETICALLY-CONTROLLED NECROTIC SPOTTING OF CORN LEAVES

1979 ◽  
Vol 59 (1) ◽  
pp. 151-152 ◽  
Author(s):  
C. G. MORTIMORE ◽  
L. F. GATES
Keyword(s):  
Environmental Conditions ◽  
Dominant Gene ◽  
Pollen Grains ◽  
Single Dominant Gene ◽  
Necrotic Spots ◽  
Corn Plants ◽  
Necrotic Spotting

Corn plants of several cultivars were found in the field in 1972 and 1973 with a prominent pattern of small whitish necrotic spots on their leaves. No organisms could be isolated from the lesions. They start as water-soaked spots, and certain environmental conditions favor their appearance. The condition was shown to be seed-transmitted. Self-pollinating affected plants and cross-pollinations between affected and healthy plants resulted in genetically significant ratios of affected and healthy plants which supported the hypothesis that the condition is controlled by a single dominant gene. It very closely resembles a genetically-controlled necrotic leaf spotting produced by Neuffer and Calvert with a mutagen acting on pollen grains.

Resistance to Lettuce Infectious Yellows Virus in Melon

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 534b-534
Author(s):  
James D. McCreight
Keyword(s):  
Cucumis Melo ◽  
Dominant Gene ◽  
Field Tests ◽  
Single Dominant Gene ◽  
Limited Data ◽  
Sweetpotato Whitefly ◽  
Sources Of Resistance ◽  
Lettuce Infectious Yellows Virus ◽  
Greenhouse Tests

Yellowing of melon (Cucumis melo L.) incited by lettuce infectious yellows virus (LIYV) reduces yield and fruit quality of infected plants. LIYV is transmitted only by the sweetpotato whitefly (Bemisia tabaci Genn.). Two naturally infected field tests indicated several potential sources of resistance to LIYV. PI 124112 and `Snake Melon' had mild symptoms in both field tests whereas PI 313970 was asymptomatic in the test in which it was included. In greenhouse tests using controlled inoculation, PI 313970 was asymptomatic, had negative ELISA assays for LIYV, and was negative for LIYV in serial transfers to Chenopodium. `Top Mark' and `PMR 5' were symptomatic, had positive ELISA assays for LIYV, and were positive for LIYV in serial transfers to Chenopodium in these greenhouse tests. Limited data indicate that resistance in PI 313970 is conditioned by a single, dominant gene.

scholarly journals Independent Resistant Reactions Expressed in Root and Tuber of Potato Breeding Lines with Introgressed Resistance to Meloidogyne chitwoodi

2009 ◽  
Vol 99 (9) ◽  
pp. 1085-1089 ◽  
Author(s):  
C. R. Brown ◽  
H. Mojtahedi ◽  
L.-H. Zhang ◽  
E. Riga
Keyword(s):  
Genetic Factors ◽  
Dominant Gene ◽  
Breeding Line ◽  
Single Dominant Gene ◽  
Solanum Bulbocastanum ◽  
Chromosome 11 ◽  
Meloidogyne Chitwoodi ◽  
Tuber Resistance ◽  
Advanced Backcross ◽  
Resistance Breaking

Resistance to Meloidogyne chitwoodi was introgressed from Solanum bulbocastanum into the cultivated gene pool of potato. A single dominant gene is responsible for resistance to race 1 reproduction on the root system. An additional form of resistance was discovered in certain advanced backcross clones. A BC5 clone, PA99N82-4, resisted invasion of tubers by available nematode juveniles whether supplied by weeds or challenged by several root resistance-breaking pathotypes. This tuber resistance is inherited as a single dominant gene and is linked to RMc1(blb). Because this gene has been mapped to chromosome 11, tuber resistance genetic factors are inferred to be on the same chromosome in coupling phase. Among 153 progeny derived from crosses with PA99N82-4, 42 recombinants, comprising both resistant root/susceptible tuber and susceptible root/resistant tubers, were found while other progeny were doubly resistant (like PA99N82-4) or doubly susceptible. Therefore, the existence of two linked genetic factors controlling independently expressed traits is confirmed. The combination of the two phenotypes is likely to be a sufficient level of resistance to avoid tuber damage from circumstances that provide exogenous juveniles proximal to the tubers in the soil. These factors are weed hosts of M. chitwoodi host races and pathotypes of M. chitwoodi that overcome RMc1(blb). Under field conditions, where a resistance-breaking pathotype of M. chitwoodi was present, tuber-resistant PA99N82-4 breeding line produced tubers which were commercially acceptable and not culled. A related breeding line, root resistant but tuber susceptible, and Russet Burbank were severely tuber damaged and commercially unacceptable.

Mechanisms of pathogenesis in Sclerotium bataticola on sunflowers. 1. Production and translocation of a necrosis-inducing toxin

1969 ◽  
Vol 47 (7) ◽  
pp. 1147-1151 ◽  
Author(s):  
Yu-Ho Chan ◽  
W. E. Sackston
Keyword(s):  
Activated Carbon ◽  
Root System ◽  
Vascular System ◽  
Early Symptom ◽  
Vascular Tissues ◽  
Detached Leaves ◽  
Necrotic Spots ◽  
Whole Plants ◽  
Necrotic Spotting

Necrotic spotting of leaves is an early symptom of attack by Sclerotium bataticola on sunflowers. Spots appear after invasion of vascular tissues by the pathogen, which does not spread appreciably from the point of inoculation.Inoculation of one stem of plants split apically to give twin stems on one root system resulted in necrotic spotting of leaves first on the inoculated, and later on the uninoculated stem. Introducing cell-free filtrates of cultures of S. bataticola into sunflower plants or detached leaves resulted in production of the same type of necrotic spots. Introduction of eosin dye, which is translocated in the vascular system, into whole plants and detached leaves produced patterns of coloration similar to the patterns of necrotic spotting. The necrosis may be attributed to a translocatable toxin produced by the fungus.It is indicated that the toxin is neither an enzyme nor a protein. It has not been eluted after adsorption by activated carbon.

INHERITANCE OF CROWN RUST RESISTANCE IN THREE ACCESSIONS OF AVENA STERILIS

1980 ◽  
Vol 22 (1) ◽  
pp. 27-33 ◽  
Author(s):  
D. E. Harder ◽  
R. I. H. McKenzie ◽  
J. W. Martens
Keyword(s):  
Rust Resistance ◽  
Dominant Gene ◽  
Crown Rust ◽  
Inheritance Of Resistance ◽  
Single Dominant Gene ◽  
Avena Sterilis ◽  
Oat Crown Rust ◽  
Crown Rust Resistance ◽  
Resistance Spectrum ◽  
Dominant Genes

The inheritance of resistance to oat crown rust was studied in three accessions of Avena sterilis L. Accession CAV 4274 originated from Morocco, CAV 4540 from Algeria, and CAV 3695 from Tunisia. Seedling rust tests on F2 backcross families indicated the presence of two dominant genes for crown rust resistance in CAV 4274. One of these, a gene conditioning resistance to most races tested, was linked or allelic to gene Pc-38, and was designated gene Pc-62. The second gene conferred resistance only to one of the six races studied, and was not tested further. In CAV 4540, a single dominant gene, Pc-63 was possibly allelic with Pc-62 and linked or allelic to Pc-38. Genes Pc-62 and 63 are generally similar to Pc-38 in their resistance spectrum, but these three genes are differentiated by races CR 102, CR 103, and CR 107. A single dominant gene in CAV 3695 appeared to be Pc-50.

THE INHERITANCE OF LOOSE SMUT RESISTANCE.: I. THE INHERITANCE OF RESISTANCE IN FOUR BARLEY VARIETIES IMMUNE TO RACE 2 OF LOOSE SMUT

1962 ◽  
Vol 42 (1) ◽  
pp. 69-77 ◽  
Author(s):  
E. N. Larter ◽  
H. Enns
Keyword(s):  
Disease Resistance ◽  
Dominant Gene ◽  
The Other ◽  
Inheritance Of Resistance ◽  
Single Dominant Gene ◽  
Loose Smut ◽  
Race 2 ◽  
Or Genes ◽  
Dominant Genes

Four barley varieties, each immune to a Valki-attacking culture of loose smut (designated as race 2), were studied with respect to the inheritance of their resistance. Jet (C.I. 967) and Nigrinudum (C.I. 2222) were each found to possess two independent dominant genes determining resistance. Steudelli (C.I. 2266) proved to be immune to race 2 through the action of a single dominant gene, while resistance of Hillsa (C.I. 1604) was found to be conditioned by two complementary dominant genes. The absence of susceptible F3 families in crosses between Jet, Nigrinudum, and Steudelli indicated that these three varieties have in common a gene or genes for resistance to the race of smut used. The two complementary genes for resistance in Hillsa proved to be distinct from those of the other three varieties under study.The use of genetic analyses of disease resistance based upon classification of F3 families of the backcross to the resistant source is described and the merits of such a method are discussed.

Soybean Aphid Resistance in Soybean Jackson Is Controlled by a Single Dominant Gene

Crop Science ◽  
2007 ◽  
Vol 47 (1) ◽  
pp. 463-463
Author(s):  
Curtis B. Hill ◽  
Yan Li ◽  
Glen L. Hartman
Keyword(s):  
Dominant Gene ◽  
Soybean Aphid ◽  
Aphid Resistance ◽  
Single Dominant Gene

Hybridization between resistant and susceptible fenugreek accessions and evaluation of Cercospora leaf spot resistance in segregating generations

2020 ◽  
Vol 100 (1) ◽  
pp. 1-15
Author(s):  
U. Subedi ◽  
S. Acharya ◽  
S. Chatterton ◽  
J. Thomas ◽  
D. Friebel
Keyword(s):  
Leaf Spot ◽  
Dominant Gene ◽  
Single Dominant Gene ◽  
Narrow Sense ◽  
Cercospora Leaf Spot ◽  
Narrow Sense Heritability ◽  
Trigonella Foenum Graecum ◽  
Resistant Genes ◽  
Simple Pathway ◽  
Resistant Genotypes

Cercospora leaf spot (CLS), caused by Cercospora traversoana, is an important phyto-pathological problem of self-pollinated fenugreek (Trigonella-foenum graecum). Developing resistant genotypes in crop plants has been considered the best option to control diseases for economic, environmental, and social reasons. However, before this can be accomplished, knowledge about the inheritance of disease-resistant genes is necessary for creating high-yielding resistant genotypes. One susceptible fenugreek cultivar, Tristar, and two resistant accessions L3717 and PI138687 were used in two-way crosses using hand emasculation and pollination technique in a greenhouse. F1 plants were grown in a greenhouse and allowed to grow till maturity to produce F2 seeds. Some flowers from F1 plants were crossed back to both resistant and susceptible parents separately to generate backcross (BC1) seeds. Parents, F1, F2, and BC1 populations were grown in the greenhouse using a RCBD with four replications. Plants were inoculated 30 d after sowing with a suspension of C. traversoana at 2 × 105 conidia mL−1. Symptoms were observed and rated on individual plants 25 d after inoculation, and plants were categorized according to susceptible or resistant reactions based on rating scores. Mean disease score was significantly different (p < 0.0001) among generations. In both the cross combinations, results showed CLS resistance in fenugreek (from L3717 and PI138687) was governed by a single dominant gene which is moderately heritable (46% narrow sense heritability). This indicates a relatively simple pathway for transfer of genes to adapted fenugreek cultivars.

scholarly journals Resistance to Monopartite Begomoviruses Associated with the Bean Leaf Crumple Disease in Phaseolus vulgaris Controlled by a Single Dominant Gene

2005 ◽  
Vol 95 (7) ◽  
pp. 819-826 ◽  
Author(s):  
Francisco Monci ◽  
Susana García-Andrés ◽  
José Antonio Maldonado ◽  
Enrique Moriones
Keyword(s):  
Phaseolus Vulgaris ◽  
Common Bean ◽  
Dominant Gene ◽  
Monopartite Begomoviruses ◽  
Tomato Yellow Leaf ◽  
Yellow Leaf ◽  
Single Dominant Gene ◽  
Long Distance ◽  
Backcross Populations ◽  
Leaf Curl

Tomato yellow leaf curl virus (TYLCV) and Tomato yellow leaf curl Málaga virus are monopartite begomoviruses (genus Begomovirus, family Geminiviridae) that infect common bean (Phaseolus vulgaris), causing bean leaf crumple disease (BLCD). This disease was found to be widespread in southern Spain and causes stunted growth, flower abortion, and leaf and pod deformation in common bean plants. Commercial yield losses of up to 100% occur. In the present study, we have identified and characterized a resistance trait to BLCD-associated viruses in the common bean breeding line GG12. This resistance resulted in a complete absence of BLCD symptoms under field conditions or after experimental inoculation. Our analysis showed that virus replication was not inhibited. However, a severe restriction to systemic virus accumulation occurred in resistant plants, suggesting that cell-to-cell or long-distance movement were impaired. In addition, recovery from virus infection was observed in resistant plants. The reaction of P. vulgaris lines GG12 (resistant) and GG14 (susceptible), and of F1, F2, and backcross populations derived from them, to TYLCV inoculation suggested that a single dominant gene conferred the BLCD resistance described here.

A Single Dominant Gene for Resistance to the Soybean Aphid in the Soybean Cultivar Dowling

Crop Science ◽  
2006 ◽  
Vol 46 (4) ◽  
pp. 1601-1605 ◽  
Author(s):  
Curtis B. Hill ◽  
Yan Li ◽  
Glen L. Hartman
Keyword(s):  
Dominant Gene ◽  
Soybean Aphid ◽  
Soybean Cultivar ◽  
Single Dominant Gene
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