Evaluation of the Phytopathological Reaction of Wild and Cultivated Olives as a Means of Finding Promising New Sources of Genetic Diversity for Resistance to Root-Knot Nematodes

Olive (Olea europaea L.) is one of the most important fruit crops in the Mediterranean Basin, because it occupies significant acreage in these countries and often has important cultural heritage and landscape value. This crop can be infected by several Meloidogyne species (M. javanica, M. arenaria, and M. incognita, among others), and only a few cultivars with some level of resistance to these nematodes have been found. Innovations in intensive olive growing using high planting densities, irrigation, and substantial amounts of fertilizers could increase the nematode population to further damaging levels. To further understand the interactions involved between olive and pathogenic nematodes and in the hope of finding solutions to the agricultural risks, this research aimed to determine the reaction of important olive cultivars in Spain and wild olives to M. javanica infection, including genotypes of the same and other O. europaea subspecies. All olive cultivars tested were good hosts for M. javanica, but high levels of nematode reproduction found in three cultivars (Gordal Sevillana, Hojiblanca, and Manzanilla de Sevilla) were substantially different. In the wild accessions, O. europaea subsp. cerasiformis (genotype W147) and O. europaea subsp. europaea var. sylvestris (genotype W224) were resistant to M. javanica at different levels, with strong resistance in W147 (reproduction factor [Rf] = 0.0003) and moderate resistance in W224 (Rf = 0.79). The defense reaction of W147 to M. javanica showed a strong increase of phenolic compounds but no hypersensitive reaction.

Download Full-text

RESISTANCE OF POTATO GENOTYPES TO Meloidogyne javanica

Revista Caatinga ◽

10.1590/1983-21252017v30n230rc ◽

2017 ◽

Vol 30 (2) ◽

pp. 536-540 ◽

Cited By ~ 1

Author(s):

JAQUELINE TAVARES SCHAFER ◽

CESAR BAUER GOMES ◽

ARIONE DA SILVA PEREIRA ◽

FERNANDA FERREIRA CRUZ ◽

DANIELLE RIBEIRO DE BARROS

Keyword(s):

Potato Cultivar ◽

Meloidogyne Javanica ◽

Temperate Climate ◽

Initial Population ◽

Nematode Reproduction ◽

Potato Plants ◽

Final Population ◽

Susceptible Control ◽

Different Levels ◽

Reproduction Factor

ABSTRACT The objective of this study was to evaluate the resistance of a group of clones and cultivars from the potato breeding program of Embrapa to Meloidogyne javanica. The experiment was conducted at Embrapa Temperate Climate, Pelotas / RS, under greenhouse conditions at temperatures of 25 ± 5°C. Individual potato plants of different genotypes [BRSIPR Bel, BRS F63 (Camila), CL02-05, F23-11-06, F32-02-06, F38-03-07, F189-09-06, F23-24-06 and F22-01-08], kept in pots with sterilized soil were inoculated with 5,000 eggs and J2 of M. javanica, using six replicates per treatment. The susceptible control, potato cultivar BRS Ana was inoculated with the same level of inoculum. Fifty-five days after inoculation, the number of galls on the roots of each plant was determined as well as the number of protuberances caused by nematodes in the different treatments. Then, the roots of each plant were processed for counting the number of eggs and J2, as well as determining the nematode reproduction factor (FR: final population / initial population). All genotypes were susceptible (FR> 1.00) to M. javanica. However, there were different levels of susceptibility among the cultivars tested.

Download Full-text

Intermediate resistance to nematode Meloidogyne paranaensis in Híbrido de Timor coffee genotypes

Australian Journal of Crop Science ◽

10.21475/ajcs.21.15.05.p2742 ◽

2021 ◽

pp. 628-633

Author(s):

Gustavo Hiroshi Sera ◽

Lucas Eduardo Fernandes ◽

Inês Cristina de Batista Fonseca ◽

Dhalton Shiguer Ito ◽

Luciana Harumi Shigueoka ◽

...

Keyword(s):

Germplasm Bank ◽

Breeding Programs ◽

Resistance Sources ◽

Final Population ◽

Randomized Design ◽

Intermediate Resistance ◽

Completely Randomized Design ◽

Moderate Resistance ◽

Different Levels ◽

Reproduction Factor

The aim of this study was to prove that Híbrido de Timor (HdT) accessions are resistance sources to Meloidogyne paranaensis. Two experiments were carried out in a greenhouse at IDR-Paraná (Londrina, Paraná State, Brazil). Open pollinated fruits were harvested from 10 accessions (HdT UFV 380-05, HdT UFV 408-10, HdT UFV 408-11, HdT UFV 408-28, HdT UFV 428-04, HdT UFV 439-14, HdT UFV 443-08, HdT UFV 445-70, HdT UFV 446-138, HdT UFV 448-75) from the EPAMIG/ UFV germplasm bank. Seeds of these accessions were sown to obtain seedlings to test the resistance to M. paranaensis. For each experiment, a completely randomized design was used with 11 treatments, eight replications and one plant per plot. Cultivar Mundo Novo IAC 376-4 was the susceptible check. Seedlings with three to four pairs of leaves were transplanted into plastic cups with a capacity of 700 mL and 1200 eggs. The J2 of M. paranaensis (IP) were inoculated after one month. The assessments were performed 134 days after inoculation, when the data of the number of eggs and J2 per gram of roots and the final population of nematodes (FP) were obtained. The reproduction factor (RF) was calculated using the formula: RF = IP / FP. To classify the resistance levels of the genotypes, the reproduction factor reduction (RFR) was used. It classified the levels from highly resistant to highly susceptible. Different levels of intermediate resistance between the accesses were observed, highlighting HdT UFV 408-28 that presented moderate resistance to M. paranaensis. HdT UFV 408-28 showed a high percentage of plants with intermediate resistance, which can be used in breeding programs aimed at resistance to M. paranaensis

Download Full-text

Methods in field chronobiology

Philosophical Transactions of the Royal Society B Biological Sciences ◽

10.1098/rstb.2016.0247 ◽

2017 ◽

Vol 372 (1734) ◽

pp. 20160247 ◽

Cited By ~ 19

Author(s):

Davide M. Dominoni ◽

Susanne Åkesson ◽

Raymond Klaassen ◽

Kamiel Spoelstra ◽

Martin Bulla

Keyword(s):

Technological Development ◽

Monitoring Systems ◽

Migratory Restlessness ◽

Biological Organization ◽

Rapid Improvement ◽

Free Living ◽

The Future ◽

In The Wild ◽

Temporal Aspect ◽

Different Levels

Chronobiological research has seen a continuous development of novel approaches and techniques to measure rhythmicity at different levels of biological organization from locomotor activity (e.g. migratory restlessness) to physiology (e.g. temperature and hormone rhythms, and relatively recently also in genes, proteins and metabolites). However, the methodological advancements in this field have been mostly and sometimes exclusively used only in indoor laboratory settings. In parallel, there has been an unprecedented and rapid improvement in our ability to track animals and their behaviour in the wild. However, while the spatial analysis of tracking data is widespread, its temporal aspect is largely unexplored. Here, we review the tools that are available or have potential to record rhythms in the wild animals with emphasis on currently overlooked approaches and monitoring systems. We then demonstrate, in three question-driven case studies, how the integration of traditional and newer approaches can help answer novel chronobiological questions in free-living animals. Finally, we highlight unresolved issues in field chronobiology that may benefit from technological development in the future. As most of the studies in the field are descriptive, the future challenge lies in applying the diverse technologies to experimental set-ups in the wild. This article is part of the themed issue ‘Wild clocks: integrating chronobiology and ecology to understand timekeeping in free-living animals’.

Download Full-text

Genetic diversity of Meloidogyne spp. parasitising potato in Brazil and aggressiveness of M. javanica populations on susceptible cultivars

Nematology ◽

10.1163/15685411-00003032 ◽

2017 ◽

Vol 19 (1) ◽

pp. 69-80 ◽

Cited By ~ 9

Author(s):

Israel L. Medina ◽

Cesar B. Gomes ◽

Valdir R. Correa ◽

Vanessa S. Mattos ◽

Philippe Castagnone-Sereno ◽

...

Keyword(s):

Genetic Diversity ◽

Rapd Markers ◽

Potato Production ◽

Potato Cultivars ◽

Root Knot Nematode ◽

Root Knot Nematodes ◽

Nematode Reproduction ◽

Meloidogyne Spp ◽

Prevalent Species ◽

Reproduction Factor

Root-knot nematodes (Meloidogyne spp.) significantly impact potato production worldwide and in Brazil they are considered one of the most important group of nematodes affecting potatoes. The objectives of this study were to survey Meloidogyne spp. associated with potatoes in Brazil, determine their genetic diversity and assess the aggressiveness of M. javanica on two susceptible potato cultivars. Fifty-seven root-knot nematode populations were identified using esterase phenotyping, including Meloidogyne javanica, M. incognita, M. arenaria and M. ethiopica. Overall, root-knot nematodes were present in ca 43% of sampled sites, in which M. javanica was the most prevalent species, and the phenotypes Est J3, J2a and J2 occurred in 91.2, 6.7 and 2.1% of the positive samples, respectively. Other species, such as M. incognita, M. arenaria and M. ethiopica, were found less frequently and occurred at rates of 6.4, 4.3 and 2.1% of the samples, respectively. Sometimes, M. javanica was found in mixtures with other root-knot nematodes in ca 10.6% of sites containing Meloidogyne. After confirming the identification of 17 isolates of M. javanica and one isolate each of M. incognita, M. arenaria and M. ethiopica by SCAR markers, the populations were used to infer their genetic diversity using RAPD markers. Results revealed low intraspecifc genetic diversity among isolates (13.9%) for M. javanica. Similarly, M. javanica sub-populations (J2a) clustered together (81% of bootstrap), indicating subtle variation from typical J3 populations. The aggressiveness of four populations of M. javanica from different Brazilian states on two susceptible potato cultivars was tested under glasshouse conditions. Results indicated differences in aggressiveness among these populations and showed that potato disease was proportional to nematode reproduction factor.

Download Full-text

The synaptic behaviour of the wild forms of Triticum turgidum and T. timopheevii

Genome ◽

10.1139/g01-031 ◽

2001 ◽

Vol 44 (4) ◽

pp. 517-522 ◽

Cited By ~ 1

Author(s):

M Martínez ◽

T Naranjo ◽

C Cuadrado ◽

C Romero

Keyword(s):

Synaptonemal Complex ◽

Triticum Turgidum ◽

Genetic System ◽

Wild Wheat ◽

Homologous Chromosomes ◽

Tetraploid Wheats ◽

Ring Bivalents ◽

In The Wild ◽

The Mean ◽

Wild Accessions

Different wild allopolyploid species of Triticeae show extensive bivalent formation at zygotene while a considerable number of multivalents is present in cultivated polyploid wheats. To study the chromosome behaviour at early meiotic stages in wild forms of tetraploid wheats Triticum turgidum and T. timopheevii (2n = 4x = 28) we have analysed the synaptic pattern in fully traced spread nuclei at mid- and late zygotene and at pachytene of wild accessions of these species. The mean number of synaptonemal complex (SC) bivalents at mid-zygotene ranged from 12.22 to 13.14 among the accessions studied indicating a strong restriction of synapsis initiation to homologous chromosomes. The mean of bivalents increased at pachytene because of the transformation of multivalents into bivalents. Ring bivalents observed at metaphase I support that SC bivalents were formed by homologous chromosomes. The average values of SC bivalents at mid-zygotene in the wild forms are much higher than the average values observed in the cultivated tetraploid wheats but similar to that of a mutant line of T. turgidum with a duplication that includes Ph1, the major homoeologous pairing suppressor locus. These results suggest that the efficiency of the mechanism operating in the homologous recognition for synapsis is higher in wild wheat populations than in cultivated varieties. Apparently, a relatively detrimental modification of the pairing regulating genetic system accompanied the domestication of the wild wheat forms.Key words: Ph1 locus, Triticum turgidum, Triticum timopheevii, synaptonemal complex, diploidisation.

Download Full-text

Grapevine Resistance to the Nematode Xiphinema index Is Durable in Muscadine-Derived Plants Obtained from Hardwood Cuttings but Not from In Vitro

Phytopathology ◽

10.1094/phyto-01-20-0008-r ◽

2020 ◽

Vol 110 (9) ◽

pp. 1565-1571

Author(s):

Van Chung Nguyen ◽

Jean-Pascal Tandonnet ◽

Samira Khallouk ◽

Cyril Van Ghelder ◽

Ulysse Portier ◽

...

Keyword(s):

Natural Resistance ◽

Parasitic Nematodes ◽

Promising Alternative ◽

Nematode Reproduction ◽

Xiphinema Index ◽

Plant Nematode ◽

Hardwood Cutting ◽

Muscadinia Rotundifolia ◽

Reproduction Factor

Breeding for varieties carrying natural resistance (R) against plant-parasitic nematodes is a promising alternative to nematicide ban. In perennial crops, the long plant−nematode interaction increases the risk for R breaking and R durability is a real challenge. In grapevine, the nematode Xiphinema index has a high economic impact by transmitting Grapevine fanleaf virus (GFLV) and, to delay GFLV transmission, rootstocks resistant to this vector are being selected, using Muscadinia rotundifolia in particular as an R source. To optimize in fine this strategy, the durability has been studied under controlled conditions in F1 and BC1 muscadine-derived resistant accessions previously obtained from either hardwood-cutting or in vitro propagation. After inoculation with a mix, in equal proportions, of four lines representative of the X. index diversity, multiplication on plants has been monitored 3 to 6 years. The nematode reproduction factor remained lower than 1 in resistant plants obtained from hardwood cuttings while it increased at values far beyond 1 in resistant plants of in vitro origin. Data for nematode numbers per gram of roots mostly paralleled those obtained for the reproduction factor. The effect of the propagation type on resistance over years was also evaluated for the ratio female/juvenile and the frequency of males. Altogether our results illustrate that the muscadine-derived resistance based on hardwood cuttings is durable. By contrast, in resistant and reference accessions obtained from in vitro, our data suggest that the increased nematode multiplication might be mainly due to the modification of root architecture consecutive to this propagation method.

Download Full-text

Resistance to Meloidogyne arenaria in Advanced Generation Breeding Lines of Peanut1

Peanut Science ◽

10.3146/pnut.22.1.0013 ◽

1995 ◽

Vol 22 (1) ◽

pp. 59-61 ◽

Cited By ~ 15

Author(s):

J. L. Starr ◽

C. E. Simpson ◽

T. A. Lee

Keyword(s):

Field Tests ◽

Recurrent Parent ◽

Meloidogyne Arenaria ◽

Root Knot Nematode ◽

Nematode Reproduction ◽

Breeding Lines ◽

Nematode Population Density ◽

Arachis Batizocoi ◽

Moderate Resistance ◽

Moderately Resistant

Abstract Levels of resistance to the root-knot nematode Meloidogyne arenaria in F2 individuals from the second, third, and fourth backcross (BC) generations were compared in seven separate tests to that of the root-knot nematode-resistant peanut germplasm line TxAG-7. Resistance of TxAG-7 was derived from the wild species Arachis batizocoi, A. cardenasii, and A. diogoi. Recurrent susceptible parents were Florunner and Tamnut 74 for the all backcrosses, Tamspan 90 for BC3 and BC4, and NC 7 and VC-1 for BC4. Resistance in these tests was defined as an inhibition of nematode reproduction relative to that of the susceptible recurrent parent. Numerous individuals with a level of resistance similar to that of TxAG-7 were identified from each backcross generation. In three field tests, the resistant BC2 genotype TP-223 supported a lower final nematode population density than did its susceptible recurrent parent Florunner. When rooted cuttings from selected BC4F2 individuals were retested to confirm the original resistance class, ratings were unchanged for those originally identified as resistant or susceptible. Of nine individuals originally identified as having moderate resistance (2.5 to 12.5% of the eggs/g roots as the susceptible recurrent parent), one was identified as susceptible, one as moderately resistant, and seven as resistant (<2.5% of the eggs/g roots) upon retest. These data are evidence that this source of resistance is readily recoverable from advanced back-cross generations.

Download Full-text

Host suitability of different wheat lines to Pratylenchus thornei under naturally infested field conditions in Turkey

Nematology ◽

10.1163/15685411-00003235 ◽

2019 ◽

Vol 21 (6) ◽

pp. 557-571 ◽

Cited By ~ 1

Author(s):

Abdelfattah A. Dababat ◽

Fouad Mokrini ◽

Salah-Eddine Laasli ◽

Şenol Yildiz ◽

Gül Erginbas-Orakci ◽

...

Keyword(s):

Field Experiments ◽

Field Conditions ◽

Nematode Reproduction ◽

Pratylenchus Thornei ◽

Wide Range ◽

Infested Field ◽

Breeding Programmes ◽

Moderate Resistance ◽

Wheat Lines ◽

Moderately Resistant

Summary The root-lesion nematode, Pratylenchus thornei, attacks a wide range of crops and causes significant reductions in global grain production. Breeding programmes are currently restricted to using parents with moderate resistance to P. thornei as cereal cultivars with complete resistance are yet to be identified. This study evaluated 484 of CIMMYT’s spring wheat accessions for resistance to P. thornei of which 56 lines were pre-identified as resistant under controlled growth room conditions. These lines were further evaluated for their resistance and tolerance reactions under field conditions, where 14 accessions maintained their resistance and 16 were moderately resistant against P. thornei. Four lines gave excellent resistant and tolerance reactions to P. thornei. The relationship between the nematode reproduction factor (Pf/Pi) and wheat grain yield in field experiments fits a linear regression model. These findings could be useful for improving P. thornei resistance in wheat.

Download Full-text

Assessment of the most suitable nematode inoculum density and plant growth period to screen coffee genotypes for their reaction to Meloidogyne incognita

Nematology ◽

10.1163/15685411-00003311 ◽

2020 ◽

Vol 22 (4) ◽

pp. 373-380

Author(s):

Santino A. Silva ◽

Anderson C.G. Bicalho ◽

Débora C. Santiago ◽

Lucas S. Cunha ◽

Andressa C.Z. Machado

Keyword(s):

Meloidogyne Incognita ◽

Genetic Screening ◽

Coffea Arabica ◽

Growth Period ◽

Root Knot Nematode ◽

Population Densities ◽

Nematode Reproduction ◽

Rf Values ◽

Reproduction Factor ◽

The Ideal

Summary One of the concerns for nematological research is the absence of information on standard nematode population densities to be used when screening to assess resistance/susceptibility levels of a genotype. In addition, the length of the growth period, especially for perennial crops such as coffee, must also be known. The objective of this work was to evaluate the ideal evaluation periods and population densities of the root-knot nematode, Meloidogyne incognita, for phenotyping Coffea arabica genotypes. Seedlings of coffee ‘Mundo Novo’ with five leaf pairs cropped in 700 cm3 plastic pots were inoculated with population densities of 700, 1400, 2800, 5600 and 11 200 eggs of M. incognita per plant and evaluated at 90, 120, 150 and 180 days after inoculation (DAI) to determine the nematode reproduction factor (RF). The use of population densities of M. incognita from 700-2000 nematodes with evaluations between 90 and 180 DAI was the most suitable to obtain higher RF values and allows earlier and more accurate evaluations, which reduces the time for phenotyping in genetic screening programmes.

Download Full-text

Resistance of Coffea arabica genotypes against Meloidogyne paranaensis and M. incognita under controlled and field conditions

Nematology ◽

10.1163/15685411-00003075 ◽

2017 ◽

Vol 19 (5) ◽

pp. 617-626 ◽

Cited By ~ 5

Author(s):

Ana Catarina J. Peres ◽

Sonia M.L. Salgado ◽

Valdir R. Correa ◽

Marcilene F.A. Santos ◽

Vanessa S. Mattos ◽

...

Keyword(s):

Coffea Arabica ◽

Agronomic Traits ◽

Germplasm Bank ◽

Nematode Reproduction ◽

Coffee Yield ◽

Infested Field ◽

Breeding Programmes ◽

Race 1 ◽

Moderately Resistant ◽

Reproduction Factor

Root-knot nematodes negatively impact on coffee yield worldwide. The use of resistant cultivars is the most effective way to manage these pests. The goal of this study was to identify Coffea arabica genotypes with resistance to Meloidogyne paranaensis and M. incognita race 1. Eighteen C. arabica genotypes (EPAMIG’s Germplasm Bank), previously selected for poor host suitability in a M. paranaensis-infested field, plus a resistant and a susceptible standard, were inoculated with these two Meloidogyne species to determine their resistance using nematode reproduction factor (). Accessions for which were considered resistant, while those for which were considered moderately resistant or susceptible, also according to statistical analysis. Five accessions from crossing ‘Catuaí Vermelho’ × ‘Amphillo MR 2-161’, one from ‘Catuaí Vermelho’ × ‘Amphillo MR 2-474’, two from ‘Timor Hybrid (UFV 408-01)’ and the standard ‘IPR-100’ were resistant to M. incognita race 1 with . Four accessions from ‘Catuaí Vermelho’ × ‘Amphillo MR 2-161’, one from ‘Timor Hybrid (UFV 408-01)’, one from ‘Catuaí Vermelho’ × ‘Amphillo MR 2-474’ and the resistant standard ‘IPR100’ were resistant to M. paranaensis (). Field evaluations with parental genotypes showed that plants that originated from progenies ‘Catuaí Vermelho’ × ‘Amphillo MR 2-161’ were resistant to M. paranaensis and also gave a good yield compared to commercial cultivars, showing promising agronomic traits that can be used in breeding programmes to develop new cultivars of C. arabica.

Download Full-text