Inheritance studies on Fusarium wilt resistance in long duration pigeonpea [Cajanus cajan (L.) Millsp.]

2018 ◽  
Author(s):  
Anil Kumar Singh ◽  
Dhirendra Kumar Singh ◽  
Rajeev Kumar ◽  
Mahendra Narain Singh ◽  
Ved Prakash Rai
Keyword(s):  
Fusarium Wilt ◽  
Goodness Of Fit ◽  
Dominant Gene ◽  
Segregation Ratio ◽  
Control Measures ◽  
Economic Losses ◽  
Susceptible Parent ◽  
Long Duration ◽  
Resistant Lines ◽  
Dominant Genes

Fusarium wilt (FW) is a major fungal disease of pigeonpea causing huge economic losses annually and breeding of FW resistant cultivars is essential as other control measures such as fungicides are expensive and harmful to environment. To understand the inheritance of FW resistance, nine populations each of F1, F2 and BCSF1 (F1 × susceptible parent) derived from crossing between three adopted but susceptible long duration pigeonpea cultivars (MA-6, MAL-13 and MAL-18) with three FW resistant lines (BSMR-846, BWR-23 and BDN-2029). All F1 plants were resistant to FW indicating the dominance of resistance. The ÷2 test for goodness-of-fit showed F2 segregation ratio of 13:3 (one dominant and one recessive), 15:1 (two dominant genes) and 3:1 (one dominant gene) in BSMR-846, BWR-23 and BDN-2029, respectively. The information generated on the genetics of FW resistance will be helpful in development of high yielding and stable wilt resistant, long duration pigeonpea varieties.

scholarly journals Inheritance of Resistance to Fusarium oxysporum f. sp. radicus-lycopersici, Causal Organism of Fusarium Crown and Root Rot in Tomato from Lycopersicon pennellii LA 1277

HortScience ◽  
1997 ◽  
Vol 32 (3) ◽  
pp. 449D-449
Author(s):  
J.W. Scott ◽  
J.P. Jones
Keyword(s):  
Fusarium Oxysporum ◽  
Root Rot ◽  
Dominant Gene ◽  
Susceptible Parent ◽  
Causal Organism ◽  
Breeding Programs ◽  
Lycopersicon Pennellii ◽  
Resistant Lines ◽  
Tomato Breeding ◽  
Crown And Root Rot

Lycopersicon pennellii accession LA 1277 was crossed to tomato (L. esculentum) and the F1 was backcrossed to tomato. Self-pollinated seed was saved from backcross plants and seedlings derived were inoculated with Fusarium oxysporum Schlecht f.sp. radicus-lycopersici Jarvis and Shoemaker, the causal agent of Fusarium crown and root rot (FCRR). Seed was saved from resistant plants that were self-pollinated and screened until homozygous resistance was verified five generations after the backcross. Three homozygous lines were crossed to Fla. 7547, a tomato breeding line susceptible to FCRR but resistant to Fusarium wilt races 1, 2, and 3. Subsequently, backcrosses were made to each parent and F2 seed were obtained. The three homozygous FCRR-resistant lines were also crossed to Ohio 89-1, which has a dominant gene for FCRR resistance presently being used in breeding programs. F2 seed were obtained from these crosses. These generations were inoculated with the FCRR pathogen. The resistant parents, F1, and backcross to the resistant parents were all healthy. The backcross to the susceptible parent and the F2 segregated healthy to susceptible plants in 1:1 and 3:1 ratios, respectively. Thus, the resistance from LA 1277 was inherited as a single dominant gene. This gene was different than the gene from Ohio 89-1 because susceptible segregants were detected in the F2 generation derived from the two resistant sources.

scholarly journals Transfer of Downy Mildew Resistance from Wild Basil (Ocimum americanum) to Sweet Basil (O. basilicum)

2018 ◽  
Vol 108 (1) ◽  
pp. 114-123 ◽  
Author(s):  
Yariv Ben-Naim ◽  
Lidan Falach ◽  
Yigal Cohen
Keyword(s):  
Downy Mildew ◽  
Dominant Gene ◽  
Susceptible Parent ◽  
Backcross Generation ◽  
Sweet Basil ◽  
Resistant Varieties ◽  
Homeologous Chromosomes ◽  
Tetraploid Parent ◽  
Dominant Genes

Sweet basil (Ocimum basilicum) is susceptible to downy mildew caused by the oomycete foliar pathogen Peronospora belbahrii. No resistant varieties of sweet basil are commercially available. Here, we report on the transfer of resistance gene Pb1 from the highly resistant tetraploid wild basil O. americanum var. americanum (PI 500945, 2n = 4x = 48) to the tetraploid susceptible O. basilicum ‘Sweet basil’ (2n = 4x = 48). F1 progeny plants derived from the interspecific hybridization PI 500945 × Sweet basil were resistant, indicating that the gene controlling resistance (Pb1) is dominant, but sterile due to the genetic distance between the parents. Despite their sterility, F1 plants were pollinated with the susceptible parent and 115 first backcross generation to the susceptible parent (BCs1) embryos were rescued in vitro. The emerging BCs1 plants segregated, upon inoculation, 5:1 resistant/susceptible, suggesting that resistance in F1 was controlled by a pair of dominant genes (Pb1A and Pb1A’). Thirty-one partially fertile BCs1 plants were self-pollinated to obtain BCs1-F2 or were backcrossed to Sweet basil to obtain the second backcross generation to the susceptible parent (BCs2). In total, 1 BCs1-F2 and 22 BCs2 progenies were obtained. The BCs1-F2 progeny segregated 35:1 resistant/susceptible, as expected from a tetraploid parent with two dominant resistant genes. The 22 BCs2 progenies segregated 1:1 resistant/susceptible (for a BCs1 parent that carried one dominant gene for resistance) or 5:1 (for a BCs1 parent that carried two dominant genes for resistance) at a ratio of 4:1. The data suggest that a pair of dominant genes (Pb1A and Pb1A’) residing on a two homeologous chromosomes is responsible for resistance of PI 500945 against P. belbahrii.

scholarly journals Inheritance and Allelic Relationship Among Downy Mildew Resistance Genes in Pearl Millet

Plant Disease ◽  
2018 ◽  
Vol 102 (6) ◽  
pp. 1136-1140 ◽  
Author(s):  
Chandramani Raj ◽  
Rajan Sharma ◽  
B. Pushpavathi ◽  
S. K. Gupta ◽  
K. Radhika
Keyword(s):  
Downy Mildew ◽  
Pearl Millet ◽  
Dominant Gene ◽  
Single Dominant Gene ◽  
Susceptible Parent ◽  
Sclerospora Graminicola ◽  
Resistant Parent ◽  
Disease Reaction ◽  
Allelic Relationship ◽  
Dominant Genes

Pearl millet downy mildew (DM), caused by Sclerospora graminicola, is of serious economic concern to pearl millet farmers in the major crop-growing areas of the world. To study the inheritance and allelic relationship among genes governing resistance to this disease, three DM-resistant pearl millet lines (834B, IP 18294-P1, and IP 18298-P1) and one susceptible line (81B) were selected on the basis of disease reaction under greenhouse conditions against two isolates of S. graminicola (Sg 526-1 and Sg 542-1). Three resistant parents were crossed with the susceptible parent to generate F1, F2, and backcross BC1P1 (susceptible parent × F1) and BC1P2 (resistant parent × F1) generations for inheritance study. To carry out a test for allelism, the three resistant parents were crossed with each other to generate F1 and F2 generations. The different generations of these crosses were screened for disease reaction against two isolates (Sg 526-1 and Sg 542-1) by artificial inoculation under greenhouse conditions. The segregation pattern of resistance in the F2 and corresponding backcross generations revealed that resistance to DM is controlled by a single dominant gene in 834B and IP 18294-P1 and by two dominant genes in IP 18298-P1. A test for allelism inferred that a single dominant gene for resistance in 834B is nonallelic to that which governs resistance in IP 18294-1, whereas one of the two dominant genes for DM resistance in IP 18298-P1 against the test isolates is allelic to the gene for DM resistance in 834B and a second gene is allelic to the resistance gene present in IP 18294-P1.

scholarly journals Novel Fusarium Wilt Resistance Genes Uncovered in the Wild Progenitors and Heirloom Cultivars of Strawberry

2021 ◽  
Author(s):  
Dominique D. A. Pincot ◽  
Mitchell J. Feldmann ◽  
Michael A. Hardigan ◽  
Mishi V. Vachev ◽  
Peter M. Henry ◽  
...  
Keyword(s):  
Fusarium Wilt ◽  
Dominant Gene ◽  
Soilborne Disease ◽  
Resistance Proteins ◽  
In The Wild ◽  
Race 1 ◽  
Race 2 ◽  
Wild Progenitors ◽  
Dominant Genes ◽  
Gene For Gene

Fusarium wilt, a soilborne disease caused by Fusarium oxysporum f. sp. fragariae, poses a significant threat to strawberry (Fragaria × ananassa) production in many parts of the world. This pathogen causes wilting, collapse, and death in susceptible genotypes. We previously identified a dominant gene (FW1) on chromosome 2B that confers resistance to race 1 of the pathogen and hypothesized that gene-for-gene resistance to Fusarium wilt was widespread in strawberry. To explore this, a genetically diverse collection of heirloom and modern cultivars and wild octoploid ecotypes were screened for resistance to Fusarium wilt races 1 and 2. Here we show that resistance to both races is widespread and that resistance to race 1 is mediated by dominant genes (FW1, FW2, FW3, FW4, and FW5) on three non-homoeologous chromosomes (1A, 2B, and 6B). The resistance proteins encoded by these genes are not yet known; however, plausible candidates were identified that encode pattern recognition receptor or other proteins known to mediate gene-for-gene resistance in plants. High-throughput genotyping assays for SNPs in linkage disequilibrium with FW1-FW5 were developed to facilitate marker-assisted selection and accelerate the development of race 1 resistant cultivars. This study laid the foundation for identifying the genes encoded by FW1-FW5, in addition to exploring the genetics of resistance to race 2 and other races of the pathogen, as a precaution to averting a Fusarium wilt pandemic.

scholarly journals DNA Markers Linked to Fusarium Wilt Race 1 Resistance in Pea

2002 ◽  
Vol 127 (4) ◽  
pp. 602-607 ◽  
Author(s):  
Melissa T. McClendon ◽  
Debra A. Inglis ◽  
Kevin E. McPhee ◽  
Clarice J. Coyne
Keyword(s):  
Fusarium Wilt ◽  
Aflp Marker ◽  
Random Amplified Polymorphic Dna ◽  
Recombinant Inbred Lines ◽  
Rapd Marker ◽  
Dominant Gene ◽  
Segregation Ratio ◽  
Causal Organism ◽  
Breeding Programs ◽  
Race 1

Dry pea (Pisum sativum L.) production in many areas of the world may be severely diminished by soil inhabiting pathogens such as Fusarium oxysporum f. sp. pisi race 1, the causal organism of fusarium wilt race 1. Our objective was to identify closely linked marker(s) to the fusarium wilt race 1 resistance gene (Fw) that could be used for marker assisted selection in applied pea breeding programs. Eighty recombinant inbred lines (RILs) from the cross of Green Arrow (resistant) and PI 179449 (susceptible) were developed through single-seed descent, and screened for disease reaction in race 1 infested field soil and the greenhouse using single-isolate inoculum. The RILs segregated 38 resistant and 42 susceptible fitting the expected 1:1 segregation ratio for a single dominant gene (χ2 = 0.200). Bulk segregant analysis (BSA) was used to screen 64 amplified fragment length polymorphism (AFLP) primer pairs and previously mapped random amplified polymorphic DNA (RAPD) primers to identify candidate markers. Eight AFLP primer pairs and 15 RAPD primers were used to screen the RIL mapping population and generate a linkage map. One AFLP marker, ACG:CAT_222, was within 1.4 cM of the Fw gene. Two other markers, AFLP marker ACC:CTG_159 at 2.6 cM linked to the susceptible allele, and RAPD marker Y15_1050 at 4.6 cM linked to the resistant allele, were also identified. The probability of correctly identifying resistant lines to fusarium wilt race 1, with DNA marker ACG:CAT_222, is 96% percent. These markers will be useful for marker assisted breeding in applied pea breeding programs.

scholarly journals Global Distribution and Genetic Heterogeneity of Border Disease Virus

Viruses ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 950
Author(s):  
Cecilia Righi ◽  
Stefano Petrini ◽  
Ilaria Pierini ◽  
Monica Giammarioli ◽  
Gian Mario De Mia
Keyword(s):  
Disease Virus ◽  
Significant Risk ◽  
Small Ruminants ◽  
Control Measures ◽  
Interspecies Transmission ◽  
Economic Losses ◽  
Border Disease Virus ◽  
Diarrhea Virus ◽  
Geographical Regions ◽  
Border Disease

Border disease virus (BDV) belongs to the genus Pestivirus of the family Flaviviridae. Interspecies transmission of BDV between sheep, cattle, and pigs occurs regularly, sometimes making diagnosis a challenge. BDV can yield substantial economic losses, including prenatal and postnatal infections in lambs, which are the primary source of infection and maintenance of the virus in the population. Since BDV is antigenically and genetically related to bovine viral diarrhea virus (BVDV), it might pose a significant risk to cattle, influencing BVDV eradication campaigns. Similarly, the presence of BDV in swine herds due to pestivirus spillover between small ruminants and pigs might cause uncertainty in classical swine fever virus (CSFV) diagnostics. Therefore, knowledge of BDV epidemiology in different geographical regions will help prevent its spread and optimize control measures. Previous epidemiological studies have shown that various BDV genotypes are predominant in different countries. This review provides an overview of the spread of BDV world-wide in different host species.

Influence of occupational heat stress on labour productivity – a case study from Chennai, India

2016 ◽  
Vol 65 (2) ◽  
pp. 245-255 ◽  
Author(s):  
Jeremiah Chinnadurai ◽  
Vidhya Venugopal ◽  
Kumaravel P ◽  
Paramesh R
Keyword(s):  
Climate Change ◽  
Heart Rate ◽  
Heat Stress ◽  
Pearson Correlation ◽  
Labour Productivity ◽  
Productivity Loss ◽  
Threshold Limit Value ◽  
Control Measures ◽  
Economic Losses ◽  
Content Type

Purpose – Raise in temperatures due to climate change is likely to increase the heat stress in occupations that are physically exerting and performed outdoors which might potentially have adverse health and productivity consequences. The purpose of this paper is to estimate the productivities in construction work under the influence of heat stress using the predicted mean vote (PMV) index. Design/methodology/approach – Field studies were conducted during May 2014 which is summer time in Chennai. Continuous heart rate of workers and wet bulb globe temperature measurements are conducted for workers engaged in different jobs in construction. Metabolic rates and the workload of the workers from heart rate were calculated using the ISO method 8996 and the PMV values are calculated using the tool developed by Malchaire based on the method ISO 7730. Direct observations and personal interviews were conducted to substantiate the productivity estimations. Findings – The results showed that workers working outdoors with moderate and heavy workload exceeded the threshold limit value of 28°C and had adverse productivity impacts (18-35 per cent productivity loss), whereas the workers engaged in light indoor work was not affected by heat stress and consequent productivity losses. The productivity estimations using the PMV index is found to be statistically significant for three types of construction works (Pearson correlation coefficient value of −0.78) and also correlated well with the observations and self-reported productivities of the workers. Originality/value – The method used in this paper provides a scientific and reliable estimation of the productivities which may benefit the industry to set realistic project completion goals in hot weather and also implement interventions and policies to protect workers’ health. Developing adaptive strategies and implementing control measures are the need of the hour to protect worker’s health and economic losses in the face of climate change.

Lantana camara (lantana).

2021 ◽  
Author(s):  
Sarah E. Thomas ◽  
Julissa Rojas-Sandoval ◽  
Pedro Acevedo-Rodríguez
Keyword(s):  
South Africa ◽  
Biological Control ◽  
Control Measures ◽  
Economic Losses ◽  
Pests And Diseases ◽  
Control Programmes ◽  
Agricultural Weed ◽  
Successful Control ◽  
The Tropics ◽  
Ornamental Shrub

Abstract L. camara is a highly variable ornamental shrub, native of the neotropics. It has been introduced to most of the tropics and subtropics as a hedge plant and has since been reported as extremely weedy and invasive in many countries. It is generally deleterious to biodiversity and has been reported as an agricultural weed resulting in large economic losses in a number of countries. In addition to this, it increases the risk of fire, is poisonous to livestock and is a host for numerous pests and diseases. L. camara is difficult to control. In Australia, India and South Africa aggressive measures to eradicate L. camara over the last two centuries have been largely unsuccessful, and the invasion trajectory has continued upwards despite control measures. This species has been the target of biological control programmes for over a century, with successful control only being reported in a few instances.

scholarly journals Serological Investigation of Peste Des Petits Ruminants in East Shewa and Arsi Zones, Oromia Region, Ethiopia

2017 ◽  
Vol 2017 ◽  
pp. 1-5 ◽  
Author(s):  
Getachew Gari ◽  
Biressaw Serda ◽  
Dejene Negesa ◽  
Fethu Lemma ◽  
Hagos Asgedom
Keyword(s):  
Significant Variation ◽  
Small Ruminants ◽  
Control Measures ◽  
Economic Losses ◽  
Enzyme Linked Immunosorbent Assay ◽  
High Seroprevalence ◽  
Serum Samples ◽  
Male And Female ◽  
Significant Difference ◽  
Important Disease

Peste des petits ruminant (PPR) is an economically important disease of small ruminants with a rapidly expanding geographical distribution. There are fragmented reports to the occurrence and distribution of the disease in Ethiopia. A total of 700 serum samples were collected from goats and sheep to detect the presence of antibody against PPR virus using Competitive Enzyme-Linked Immunosorbent Assay (C-ELISA). An overall PPR seropositivity was reported to be 48.43% in the area. There is no statistically significant difference in the seroprevalence of the disease between sheep and goats (50.85% and 46.68%), respectively. However, there was statistically significant variation (P<0.05) in the seroprevalence of the disease in young (33.9%) and adult (55.8%) age categories. The seroprevalence in male and female was 42.07% and 50.09%, respectively, where the variation was statistically not significant (P>0.05). High seroprevalence of Peste des petites ruminants in the study area indicated the virus circulation and endemicity of the disease. The disease causes substantial economic losses by affecting the livelihood of the farmers. Therefore, control measures should be put in place to minimize the loss associated with the disease.

scholarly journals The mechanism whereby the genes M1 and M2 in Paramecium aurelia, stock 540, control growth of the mate-killer (mu) particles

1962 ◽  
Vol 3 (1) ◽  
pp. 24-50 ◽  
Author(s):  
I. Gibson ◽  
G. H. Beale ◽  
E. C. R Reeve
Keyword(s):  
Recipient Cell ◽  
Physiological Activity ◽  
Dominant Gene ◽  
Initial Number ◽  
Irregular Distribution ◽  
Large Numbers ◽  
Control Growth ◽  
Phenotypic Manifestation ◽  
A Cell ◽  
Dominant Genes

1. Replacement of the dominant genes M1 and M2 in Paramecium aurelia, stock 540 (syngen/variety 1), results in loss of ability to maintain mu particles and manifestation of mate-killing after a delay of eight to fifteen fissions in most cells. The change, when it does occur, is relatively abrupt, extending over less than the space of one inter-fission period.2. The delay between change of genotype and loss of mu particles is interpreted as being due to presence in the initial cytoplasm of some thousand ‘metagons’, which are non-replicating gene derivatives having the physiological activity of the corresponding genes. During successive fissions of paramecia deprived of M1 and M2 the metagons are passively distributed amongst the progeny, until virtually all animals lack them.3. On reaching a stage at which some individuals of genotype m1m1m2m2 contain only a single metagon, the paramecia still contain large numbers of mu particles and are mate-killers. Fission of such animals gives rise to one daughter again with mu particles, and another in which the latter are destroyed during the next inter-fission period.4. By induced cytoplasmic exchange between conjugants, metagons can be transferred from one animal to another via the cytoplasm. Where such transference is into an animal not originally containing mu particles, that animal is converted into a condition in which it favours the maintenance of mu particles and transmits the latter to one or more of its offspring.5. Distribution of metagons amongst progeny of dividing paramecia is not random, due possibly to clumping of the metagons. Induced cytoplasmic exchange seems to break up the clumps.6. Reintroduction of a dominant gene (M2) into a cell recently deprived of the same gene, succeeds—even after fifteen fissions—in re-establishing the ability to support growth of mu particles, provided that the recipient cell contains at least one metagon and one or more mu particles. There is a regular lag of only one fission between introduction of such a dominant gene and its phenotypic manifestation.7. Mathematical formulae are developed for calculating the expected initial number of metagons, the proportions of animals lacking mu particles at each fission following loss of the dominant genes, and the proportions of cells containing 0, 1, 2 …, etc. metagons per cell at any stage. The consequences of one of the possible types of irregular distribution of metagons in dividing paramecia are also considered mathematically.

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