scholarly journals Mapping Resistance to Alternaria cucumerina in Cucumis melo

2017 ◽  
Vol 107 (4) ◽  
pp. 427-432 ◽  
Author(s):  
James Daley ◽  
Sandra Branham ◽  
Amnon Levi ◽  
Richard Hassell ◽  
Patrick Wechter
Keyword(s):  
Cucumis Melo ◽  
Genetic Basis ◽  
Genotyping By Sequencing ◽  
Susceptible Parent ◽  
Single Seed Descent ◽  
Lesion Area ◽  
Lesion Formation ◽  
Resistant Parent ◽  
Greenhouse Study ◽  
Yield And Quality

Infection with Alternaria cucumerina causes Alternaria leaf blight (ALB), a disease characterized by lesion formation on leaves, leading to substantial yield and quality losses in Cucumis melo (melon). Although fungicides are effective against ALB, reduction in the frequency of application would be economically and environmentally beneficial. Resistant melon lines have been identified but the genetic basis of this resistance has not been determined. A saturated melon genetic map was constructed with markers developed through genotyping by sequencing of a recombinant inbred line population (F6 to F10; n = 82) derived from single-seed descent of a F2 population from a cross between the ALB-resistant parent MR-1 and the ALB-susceptible parent Ananas Yokneum. The population was evaluated for A. cucumerina resistance with an augmented block greenhouse study using inoculation with the wounded-leaf method. Multiple quantitative trait loci (QTL) mapping identified two QTL that explained 33.9% of variation in lesion area. Several candidate genes within range of these QTL were identified using the C. melo v3.5 genome. Markers linked to these QTL will be used to accelerate efforts to breed melon cultivars resistant to ALB.

Dieldrin-resistance in a strain of Aedes aegypti (L.) from Puerto Rico

1964 ◽  
Vol 55 (3) ◽  
pp. 519-526 ◽  
Author(s):  
A. M. Guneidy
Keyword(s):  
Puerto Rico ◽  
Aedes Aegypti ◽  
Cross Resistance ◽  
Autosomal Gene ◽  
Normal Strain ◽  
Susceptible Parent ◽  
Resistant Parent ◽  
Back Cross ◽  
Direct Cross ◽  
Resistance Spectrum

The cross-resistance characteristics of a dieldrin-resistant strain of Aedes aegypti (L.) from Puerto Rico were investigated by comparative tests on the adults of this and of a normal strain, using various insecticides. A resistance spectrum typical of that associated with resistance to BHC/dieldrin in other insects was revealed, characterised by slight or negligible cross-resistance to DDT, malathion and diazinon.The mode of inheritance of dieldrin-resistance was studied by determining resistance levels in the progeny of direct crosses of the resistant and normal strains and of back-crosses. The F1 generation of the direct cross was of intermediate resistance, and the F1 generation showed 1:2:1 segregation into normal, intermediate and resistant individuals. Both back-crosses showed 1:1 segregation into susceptible and intermediate individuals when the back-cross was to the susceptible parent, or into intermediate and resistant individuals when it was to the resistant parent, and these results were confirmed when one genotype was eliminated and the back-cross was repeated. These results indicate monofactorial inheritance of an autosomal gene with intermediate dominance, which is typical of the BHC/dieldrin type of resistance.

scholarly journals Downregulated expression of S2-RNase attenuates self-incompatibility in “Guiyou No. 1” pummelo

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Jianbing Hu ◽  
Qiang Xu ◽  
Chenchen Liu ◽  
Binghao Liu ◽  
Chongling Deng ◽  
...  
Keyword(s):  
Genetic Basis ◽  
Fruit Set ◽  
Spontaneous Mutation ◽  
Practical Significance ◽  
Spontaneous Mutant ◽  
Self Incompatibility ◽  
Yield And Quality ◽  
Citrus Maxima ◽  
Self Compatibility

AbstractSelf-incompatibility (SI) substantially restricts the yield and quality of citrus. Therefore, breeding and analyzing self-compatible germplasm is of great theoretical and practical significance for citrus. Here, we focus on the mechanism of a self-compatibility mutation in ‘Guiyou No. 1’ pummelo (Citrus maxima), which is a spontaneous mutant of ‘Shatian’ pummelo (Citrus maxima, self-incompatibility). The rate of fruit set and the growth of pollen tubes in the pistil confirmed that a spontaneous mutation in the pistil is responsible for the self-compatibility of ‘Guiyou No. 1’. Segregation ratios of the S genotype in F1 progeny, expression analysis, and western blotting validated that the reduced levels of S2-RNase mRNA contribute to the loss of SI in ‘Guiyou No. 1’. Furthermore, we report a phased assembly of the ‘Guiyou No. 1’ pummelo genome and obtained two complete and well-annotated S haplotypes. Coupled with an analysis of SV variations, methylation levels, and gene expression, we identified a candidate gene (CgHB40), that may influence the regulation of the S2-RNase promoter. Our data provide evidence that a mutation that affects the pistil led to the loss of SI in ‘Guiyou No. 1’ by influencing a poorly understood mechanism that affects transcriptional regulation. This work significantly advances our understanding of the genetic basis of the SI system in citrus and provides information on the regulation of S-RNase genes.

scholarly journals Inheritance of Resistance to Gray Leaf Spot in Crosses Involving Selected Resistant Inbred Lines of Corn

1998 ◽  
Vol 88 (9) ◽  
pp. 972-982 ◽  
Author(s):  
S. T. Coates ◽  
D. G. White
Keyword(s):  
Leaf Area ◽  
Leaf Spot ◽  
Inbred Lines ◽  
Gray Leaf Spot ◽  
Inheritance Of Resistance ◽  
Generation Mean Analysis ◽  
Susceptible Parent ◽  
Dominance Model ◽  
Resistant Parent ◽  
Naturally Occurring

Three populations derived from crosses of selected resistant inbreds (061, B37HtN, and DS:74:1071) with susceptible inbred FR1141 and a population derived from a cross of B37 × B37HtN were evaluated for gray leaf spot severity in 1992 and 1993 at Urbana, IL, and Andrews, NC. Populations included the susceptible parent (P1), the resistant parent (P2), F1 and F2 generations, backcrosses BCP1 and BCP2, and, when space and seed were available, one or more of the F3, BCP1S1, and BCP2S1 generations. Plants at Urbana were inoculated, and naturally occurring disease was relied upon at Andrews. Individual plants were rated by visually estimating the percent leaf area blighted (necrotic). Generation mean analysis of data combined over years or locations indicated that a simple additive-dominance model was able to explain the inheritance of resistance for all populations. Dominance effects were detected in all population evaluated. For the FR1141 × 061 and FR1141 × B37HtN populations, dominance was significant at early ratings, but not at late ratings. Results from generation mean analysis for individual years, locations, and rating were variable.

Effect of Solid CO2 Generator Treatment on Fruit Yield and Quality of Korean Melon(Cucumis melo var. hybrida)

2014 ◽  
Vol 23 (2) ◽  
pp. 83-87 ◽  
Author(s):  
Yong Seub Shin ◽  
습 신용 ◽  
Ji Eun Lee ◽  
Min Ki Kim ◽  
Joung Do Cheung ◽  
...  
Keyword(s):  
Cucumis Melo ◽  
Fruit Yield ◽  
Yield And Quality

Inheritance of powdery mildew resistance in pea

1997 ◽  
Vol 77 (3) ◽  
pp. 307-310 ◽  
Author(s):  
K. R. Tiwari ◽  
G. A. Penner ◽  
T. D. Warkentin
Keyword(s):  
Powdery Mildew ◽  
Genetic Basis ◽  
Recessive Gene ◽  
Growth Conditions ◽  
Parasitic Fungus ◽  
Grain Legume ◽  
Erysiphe Pisi ◽  
Legume Crop ◽  
Yield And Quality ◽  
Significant Yield

Pea, an important grain legume crop, suffers significant yield and quality losses because of infections by the parasitic fungus Erysiphe pisi Syd., the causal agent of powdery mildew. Most pea cultivars in western Canada are susceptible to this fungus. The genetic basis of resistance found in certain Canadian cultivars is unclear. Resistant cultivars and lines were intercrossed with each other and crossed with susceptible lines to determine the genetic basis of resistance. Resistance in the cultivars Highlight, AC Tamor, Tara, Mexique 4, Stratagem and lines JI 210, JI 1951, JI 1210 was found to be conferred by a single recessive gene, er-1. The resistance in line JI 2480 is conferred by a different recessive gene, er-2. Resistance provided by er-1 was durable under both field and growth cabinet conditions, however, resistance of er-2 was broken under controlled growth conditions. Combining er-1 and er-2 in a cultivar could increase the durability of resistance. Key words: pea, Pisum sativum, powdery mildew, Erysiphe pisi, inheritance, resistance

scholarly journals Macrophage-derived apolipoprotein E ameliorates dyslipidemia and atherosclerosis in obese apolipoprotein E-deficient mice

2008 ◽  
Vol 294 (2) ◽  
pp. E284-E290 ◽  
Author(s):  
Robin D. Atkinson ◽  
Kimberly R. Coenen ◽  
Michelle R. Plummer ◽  
Marnie L. Gruen ◽  
Alyssa H. Hasty
Keyword(s):  
Adipose Tissue ◽  
Apolipoprotein E ◽  
Plasma Lipids ◽  
Atherosclerotic Lesion ◽  
Density Lipoprotein ◽  
Tissue Expansion ◽  
Lower Plasma ◽  
Lesion Area ◽  
Lesion Formation ◽  
Atherosclerotic Lesion Formation

Previous studies have demonstrated that macrophage-derived apolipoprotein E (apoE) reduces atherosclerotic lesion formation in lean apoE-deficient (−/−) mice. apoE has also been demonstrated to play a role in adipocyte differentiation and lipid accumulation. Because the prevalence of obesity has grown to epidemic proportions, we sought to determine whether macrophage-derived apoE could impact atherosclerotic lesion formation or adipose tissue expansion and inflammation in obese apoE−/− mice. To this end, we transplanted obese leptin-deficient ( ob/ ob) apoE−/− mice with bone marrow from either ob/ ob;apoE−/− or ob/ ob;apoE+/+ donors. There were no differences in body weight, total body adipose tissue, or visceral fat pad mass between recipient groups. The presence of macrophage-apoE had no impact on adipose tissue macrophage content or inflammatory cytokine expression. Recipients of apoE+/+ marrow demonstrated 3.7-fold lower plasma cholesterol ( P < 0.001) and 1.7-fold lower plasma triglyceride levels ( P < 0.01) by 12 wk after transplantation even though apoE was present in plasma at concentrations <10% of wild-type levels. The reduced plasma lipids reflected a dramatic decrease in very low density lipoprotein and a mild increase in high-density lipoprotein levels. Atherosclerotic lesion area was >10-fold lower in recipients of ob/ ob;apoE+/+ marrow ( P < 0.005). Similar results were seen in leptin receptor-deficient ( db/ db) apoE−/− mice. Finally, when bone marrow transplantation was performed in 4-mo-old ob/ ob;apoE−/− and db/ db;apoE−/− mice with preexisting lesions, recipients of apoE+/+ marrow had a 2.8-fold lower lesion area than controls ( P = 0.0002). These results demonstrate that macrophage-derived apoE does not impact adipose tissue expansion or inflammatory status; however, even very low levels of macrophage-derived apoE are capable of reducing plasma lipids and atherosclerotic lesion area in obese mice.

scholarly journals Heterosis Studies in Muskmelon (Cucumis melo L.) for Yield and Quality Traits

2021 ◽  
Vol 10 (2) ◽  
pp. 1534-1549
Author(s):  
Shivaji Kallappa Duradundi V. D. Gasti ◽  
Ravindra Mulage Deelipkumar A. Masuthi
Keyword(s):  
Cucumis Melo ◽  
Quality Traits ◽  
Yield And Quality ◽  
Cucumis Melo L
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