Parasitic interactions of Orobanche with selected Nicotiana species and identification of effective resistant genotypes

Spodoptera litura an important insect pest of groundnut causes yield loss up to 71% in India. Though many effective chemicals are available to control Spodoptera, host plant resistance is the most desirable, economic and eco-friendly strategy. In the present study, groundnut mini core (184), recombinant inbred lines (318) and elite genotypes (44) were studied for their reaction to Spodoptera litura under hot spot location at Dharwad. Heritable component of variation existed for resistance to Spodoptera in groundnut mini core, recombinant inbred lines and elite genotypes indicating scope for selection of Spodoptera resistant genotypes. Only 29 (15%) genotypes belonging to hypogaea, fastigiata and hirsuta botanical varieties under mini core set, 15 transgressive segregants belonging to fastigiata botanical variety among 318 recombinant inbred lines and three genotypes belonging to hypogaea and fastigiata botanical varieties under elite genotypes showed resistance to Spodoptera litura with less than 10% leaf damage. Negative correlation existed between resistance to Spodoptera and days to 50 per cent flowering indicating late maturing nature of resistant genotypes. Eight resistant genotypes (ICG 862, ICG 928, ICG 76, ICG 2777, ICG 5016, ICG 12276, ICG 4412 and ICG 9905) under hypogaea botanical variety also had significantly higher pod yield. These diverse genotypes could serve as potential donors for incorporation of Spodoptera resistance in groundnut.

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Hazelnut Pollination

HortScience ◽

10.21273/hortsci.33.3.555d ◽

1998 ◽

Vol 33 (3) ◽

pp. 555d-555

Author(s):

J.L. Olsen ◽

S.A. Mehlenbacher ◽

A.N. Azarenko

Keyword(s):

Single Gene ◽

Pistillate Flower ◽

Temperature Dependent ◽

Multiple Alleles ◽

Anisogramma Anomala ◽

Molecular Aspects ◽

Management Recommendations ◽

Pollen Shed ◽

Resistant Genotypes ◽

Pollination And Fertilization

Hazelnuts are wind-pollinated, monoecious, mostly dichogamous, and self-incompatible of the sporophytic type. About 90% of the cultivars studied are protandrous. Anthesis of the pistillate flower is temperature-dependent and occurs from December through February, with its peak in January. Stigmatic surfaces may remain receptive for up to 3 months. Four to 5 months separate pollination and fertilization of the ovule, which usually occurs between mid-May and the end of June in Oregon. A 10% pollinizer density has been the standard, with a recommended distance of <20 m between the main cultivar and the nearest pollinizer. Two or three different pollinizer varieties with different times of pollen shed are recommended. The Oregon hazelnut industry is presently combating the fungal disease, Eastern Filbert Blight, Anisogramma anomala. Part of the current management recommendations are to reduce the susceptible pollinizer varieties to a density of around 5%, and then gradually replace those left with immune or more-resistant genotypes. Recent research by S.A. Mehlenbacher refined methods of using fluorescense microscopy to quickly determine genotype compatibility. The self-incompatiblity is controlled by a single gene with multiple alleles. The biochemical, physiological, and molecular aspects of sporophytic self-incompatiblity are being research by A.N. Azarenko.

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Genetic diversity of native cultivated cacao accessions (Theobroma cacao L.) in Nicaragua

Plant Genetic Resources ◽

10.1017/s1479262112000238 ◽

2012 ◽

Vol 10 (3) ◽

pp. 254-257

Author(s):

Erwin Aragon ◽

Claudia Rivera ◽

Helena Korpelainen ◽

Aldo Rojas ◽

Paula Elomaa ◽

...

Keyword(s):

Genetic Diversity ◽

Theobroma Cacao ◽

Phytophthora Palmivora ◽

Genetic Composition ◽

Breeding Programmes ◽

Black Pod ◽

Black Pod Disease ◽

Parental Lines ◽

Resistant Genotypes ◽

Theobroma Cacao L

A total of 60 farmers' cacao accessions (Theobroma cacao L.) from Nicaragua were investigated using microsatellite markers to reveal their genetic composition and to identify potentially resistant genotypes against the black pod disease caused by Phytophthora palmivora. These accessions were compared with 21 breeders' accessions maintained locally, two Criollo accessions from Costa Rica and two accessions from Ecuador. The analyses showed a low level of differentiation among groups of farmers' accessions (FST = 0.06) and that six Nicaraguan accessions were genetically closely related to the two Criollo accessions used as a reference. In addition, seven distinct genotypes were found to have allelic composition that may indicate linkage to resistance alleles, thus being potential parental lines in future breeding programmes.

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Assessment of physiological races of Exserohilum turcicum isolates from maize in Argentina and Brazil

Tropical Plant Pathology ◽

10.1007/s40858-020-00417-x ◽

2021 ◽

Author(s):

Barbara Ludwig Navarro ◽

Lucia Ramos Romero ◽

María Belén Kistner ◽

Juliana Iglesias ◽

Andreas von Tiedemann

Keyword(s):

Exserohilum Turcicum ◽

Breeding Programs ◽

Physiological Races ◽

Maize Leaves ◽

Race 1 ◽

Resistance Reaction ◽

Qualitative Resistance ◽

Maize Plants ◽

Corn Leaf Blight ◽

Resistant Genotypes

AbstractNorthern corn leaf blight (NCLB) is one of the most important diseases in maize worldwide. It is caused by the fungus Exserohilum turcicum, which exhibits a high genetic variability for virulence, and hence physiological races have been reported. Disease control is based mainly on fungicide application and host resistance. Qualitative resistance has been widely used to control NCLB through the deployment of Ht genes. Known pathogen races are designated according to their virulence to the corresponding Ht gene. Knowledge about of E. turcicum race distribution in maize-producing areas is essential to develop and exploit resistant genotypes. Maize leaves showing distinct elliptical grey-green lesions were collected from maize-producing areas of Argentina and Brazil, and 184 monosporic E. turcicum isolates were obtained. A total of 66 isolates were collected from Argentina during 2015, 2018 and 2019, while 118 isolates from Brazil were collected during 2017, 2018 and 2019. All isolates were screened on maize differential lines containing Ht1, Ht2, Ht3 and Htn1 resistance genes. In greenhouse experiments, inoculated maize plants were evaluated at 14 days after inoculation. Resistance reaction was characterized by chlorosis, and susceptibility was defined by necrosis in the absence of chlorosis. The most frequent race was 0 in both Argentina (83%) and Brazil (65%). Frequencies of race 1 (6% and 24%) and race 23N (5% and 10%) were very low in Argentina and Brazil, respectively. The high frequency of race 0 isolates provides evidence that qualitative resistance based on the tested Ht genes is not being used extensively in Argentina and Brazil to control NCLB. This information may be relevant for growers and breeding programs as the incidence of NCLB is increasing in both countries.

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Search for Resistant Genotypes to Cuscuta campestris Infection in Two Legume Species, Vicia sativa and Vicia ervilia

Plants ◽

10.3390/plants10040738 ◽

2021 ◽

Vol 10 (4) ◽

pp. 738

Author(s):

Eva María Córdoba ◽

Mónica Fernández-Aparicio ◽

Clara Isabel González-Verdejo ◽

Carmela López-Grau ◽

María del Valle Muñoz-Muñoz ◽

...

Keyword(s):

Agricultural Production ◽

Host Plants ◽

Resistance Breeding ◽

Parasitic Plants ◽

Vicia Sativa ◽

Common Vetch ◽

Germplasm Collections ◽

Bitter Vetch ◽

Cuscuta Campestris ◽

Resistant Genotypes

The dodders (Cuscuta spp.) are parasitic plants that feed on the stems of their host plants. Cuscuta campestris is one of the most damaging parasitic plants for the worldwide agricultural production of broad-leaved crops. Its control is limited or non-existent, therefore resistance breeding is the best alternative both economically and environmentally. Common vetch (Vicia sativa) and bitter vetch (Vicia ervilia) are highly susceptible to C. campestris, but no resistant genotypes have been identified. Thus, the aim of this study was to identify in V. sativa and V.ervilia germplasm collections genotypes resistant to C. campestris infection for use in combating this parasitic plant. Three greenhouse screening were conducted to: (1) identify resistant responses in a collection of 154 accessions of bitter vetch and a collection of 135 accessions of common vetch genotypes against infection of C. campestris; (2) confirm the resistant response identified in common vetch accessions; and (3) characterize the effect of C. campestris infection on biomass of V. sativa resistant and susceptible accessions. Most common vetch and bitter vetch genotypes tested were susceptible to C. campestris. However, the V. sativa genotype Vs.1 exhibited high resistance. The resistant phenotype was characterized by a delay in the development of C. campestris posthaustorial growth and a darkening resembling a hypersensitive-like response at the penetration site. The resistant mechanism was effective in limiting the growth of C. campestris as the ratio of parasite/host shoot dry biomass was more significantly reduced than the rest of the accessions. To the best or our knowledge, this is the first identification of Cuscuta resistance in V. sativa genotypes.

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Appraisal of resistant genotypes against brinjal shoot and fruit borer (BSFB), Leucinodes orbonalis, Guenee

Journal of the Bangladesh Agricultural University ◽

10.3329/jbau.v16i2.37965 ◽

2018 ◽

Vol 16 (2) ◽

pp. 227-231

Author(s):

Hafija Sultana ◽

Md Aabdul Mannan ◽

Md Mostofa Kamal ◽

Khan Golam Quddus ◽

Shimul Das

Keyword(s):

Pot Experiment ◽

Leucinodes Orbonalis ◽

Fruit Borer ◽

Three Stages ◽

Fruit Damage ◽

Shoot Damage ◽

Resistant Genotypes

The main purpose of this study was to find out the best variety of brinjal having resistance to BSFB. A pot experiment was carried out at the germplasm centre, Agrotechnology Discipline, Khulna University, Khulna during February 2014 to August 2014. The experiment was laid out in CRD using thirteen varieties with five replications. The varieties were V1=BARI begun-1, V2=BARI begun-4, V3=BARI begun-5, V4=BARI begun-6, V5=BARI begun-7, V6=BARI begun-8, V7=BARI begun-9, V8=BARI begun-10, V9=Makra, V10=Muktokashi, V11=Lalita, V12=Hazra, V13=Chaga. Data were collected on total number of shoot, total number of infested shoot, percentage of shoot damage, percentage of shoot infestation reduction, numbers of larvae per infested shoot, total number of fruit, percentage of fruit damage, percentage of fruit infestation reduction, numbers of larvae per infested fruit. Results have shown that the minimum shoot infestation was found in BARI begun-6 (29.60%, 32.40%, 29.86% and 29.38%, respectively at four different stages of eggplant). Percent of fruit infestation was minimum in V4 (BARI begun-6) (25.16%, 27.42% and 25.40% at three stages respectively).J. Bangladesh Agril. Univ. 16(2): 227-231, August 2018

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Kinetic Parameters of the Extraction of Tannis from Three Nicotiana Species

2020 7th International Conference on Energy Efficiency and Agricultural Engineering (EE&AE) ◽

10.1109/eeae49144.2020.9279079 ◽

2020 ◽

Author(s):

Stanislava Tasheva ◽

Vanya Gandova ◽

Venelina Popova ◽

Tanya Ivanova ◽

Albena Stoyanova

Keyword(s):

Kinetic Parameters ◽

Nicotiana Species

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Fossil Record of Parasitism on Marine Invertebrates with Special Emphasis on the Platyceratid-Crinoid Interaction

The Paleontological Society Papers ◽

10.1017/s1089332600001091 ◽

2002 ◽

Vol 8 ◽

pp. 195-210 ◽

Cited By ~ 33

Author(s):

Tomasz K. Baumiller ◽

Forest J. Gahn

Keyword(s):

Fossil Record ◽

Marine Invertebrates ◽

Marine Diversity ◽

Parasitic Interactions ◽

Explicit Criteria ◽

Lower Frequencies

The paleontological literature on marine invertebrates is rich in supposed examples of parasitism and our tabulation shows a nearly even distribution of reported cases through the post-Cambrian Phanerozoic. Slightly lower frequencies characterize the Triassic and Jurassic and higher frequencies the Cretaceous and Tertiary, and the pattern roughly mirrors Sepkoski's (1984) marine diversity curve. The total number of parasitic associations for any geologic period rarely exceeds a dozen, yet few of the reported examples provide explicit criteria distinguishing parasitism from predation, commensalism, or mutualism. We evaluated the published examples using the following criteria: (1) evidence of a long-term relationship between two organisms, (2) benefit of interaction to supposed parasite, and (3) detriment of interaction to the host We found that only in exceptional cases were these criteria fulfilled. One example that provides much information on parasitic interactions involves platyceratids and crinoids and we summarize the evidence for the parasitic interaction between these two groups of organisms.

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