Screening Sweetpotato Genotypes for Resistance to a North Carolina Isolate of Meloidogyne enterolobii

Plant Disease ◽  
2020 ◽  
Author(s):  
Tanner Schwarz ◽  
Eric Davis ◽  
G. Craig Yencho ◽  
Kenneth Pecota ◽  
Chunying Li ◽  
...  
Keyword(s):  
North Carolina ◽  
Ipomoea Batatas ◽  
Post Inoculation ◽  
State University ◽  
Root Knot Nematode ◽  
Soil Mixture ◽  
Initial Inoculum ◽  
Meloidogyne Enterolobii ◽  
Nematode Eggs ◽  
Reproduction Factor

Potential resistance to the guava root-knot nematode, Meloidogyne enterolobii, in ninety-one selected sweetpotato [Ipomoea batatas (L.) Lam.] genotypes was evaluated in six greenhouse experiments. Ten thousand eggs of M. enterolobii were inoculated on each sweetpotato genotype grown in a 3:1 sand to soil mixture. Sixty days post inoculation, percent of total roots with nematode-induced galls was determined, and nematode eggs were extracted from roots. Significant differences (P ˂ 0.001) among sweetpotato genotypes were found in all six tests for gall rating, total eggs, and eggs per gram of root. Resistant sweetpotato genotypes were determined by final eggs per root system divided by the initial inoculum where Pf/Pi < 1 (reproduction factor; final egg count divided by initial inoculum of 10,000 eggs), and statistical mean separations were confirmed by Fisher’s LSD t test. Our results indicated that 19 out of 91 tested sweetpotato genotypes were resistant to M. enterolobii. Some of the susceptible genotypes included ‘Covington’, ‘Beauregard’, ‘NCDM04-001’, and ‘Hernandez’. Some of the resistant sweetpotato genotypes included ‘Tanzania’, ‘Murasaki-29’, ‘Bwanjule’, ‘Dimbuka-Bukulula’, ‘Jewel’, and ‘Centennial’. Most of the 19 resistant sweetpotato genotypes supported almost no M. enterolobii reproduction with less than 20 eggs/g root of M. enterolobii. A number of segregants from a ‘Tanzania’ x ‘Beauregard’ cross demonstrated strong resistance to M. enterolobii observed in the ‘Tanzania’ parent. In collaboration with NC State University sweetpotato breeding program, several of the genotypes evaluated in these tests are now being used to incorporate the observed resistance to M. enterolobii into commercial sweetpotato cultivars.

scholarly journals REACTION OF PSIDIUM SPP. ACCESSIONS TO DIFFERENT LEVELS OF INOCULATION WITH MELOIDOGYNE ENTEROLOBII

2019 ◽  
Vol 32 (2) ◽  
pp. 419-428
Author(s):  
PATRÍCIA GOMES DE OLIVEIRA ◽  
MANOEL ABILIO DE QUEIRÓZ ◽  
JOSÉ MAURO DA CUNHA E CASTRO ◽  
JULIANA MARTINS RIBEIRO ◽  
RONALDO SIMÃO DE OLIVEIRA ◽  
...  
Keyword(s):  
Yield Loss ◽  
State University ◽  
Fresh Weight ◽  
Root Knot Nematode ◽  
Second Stage ◽  
Meloidogyne Enterolobii ◽  
Positive Results ◽  
Different Levels ◽  
Reproduction Factor ◽  
Main Factor

ABSTRACT Meloidogyne enterolobii associated with Fusarium solani causes the guava decay, which is the main factor of yield loss in guava crops and limits guava production in Brazil. Therefore, searching for guava genotypes (Psidium spp.) with resistance to M. enterolobii is important to control this root-knot nematode. The objective of the present work was to evaluate the reaction of Psidium spp. accessions from the Germplasm Bank of the Bahia State University (UNEB) to different levels of inoculation with M. enterolobii. Guava seedlings were inoculated with 600, 1,600, and 2,000 eggs + J2 second stage juveniles of M. enterolobii and the root fresh weight, total number of eggs (TNE), and reproduction factor (RF) were evaluated. The results were subjected to ANOVA and means were clustered using the Scott-Knott test at 5% probability. The diversity of accessions was estimated using the Tocher's clustering and UPGMA methods. The nematode RF reduced in some accessions with increasing inoculation levels of the nematode. However, the RF increased in some accessions with high levels of inoculation. Plants of the Y50 accession were immune or resistant to M. enterolobii, indicating variability of reaction of plants to the nematode within the Psidium genus. The resistance of Psidium accessions to M. enterolobii needs to be measured with different inoculation levels to verify the existence of false-positive results, since the evaluated accessions, including the Paluma cultivar, presented distinct reactions regarding RF in the three levels of inoculation used.

scholarly journals ‘Covington’ Sweetpotato

HortScience ◽  
2008 ◽  
Vol 43 (6) ◽  
pp. 1911-1914 ◽  
Author(s):  
G. Craig Yencho ◽  
Kenneth V. Pecota ◽  
Jonathan R. Schultheis ◽  
Zvezdana-Pesic VanEsbroeck ◽  
Gerald J. Holmes ◽  
...  
Keyword(s):  
North Carolina ◽  
Ipomoea Batatas ◽  
The United States ◽  
Matter Content ◽  
Dry Matter Content ◽  
State University ◽  
Root Knot Nematode ◽  
Storage Roots ◽  
North Carolina State University ◽  
Southern Root Knot Nematode

‘Covington’ is an orange-fleshed, smooth-skinned, rose-colored, table-stock sweetpotato [Ipomoea batatas (L.) Lam.] developed by North Carolina State University (NCSU). ‘Covington’, named after the late Henry M. Covington, an esteemed sweetpotato scientist at North Carolina State, was evaluated as NC98-608 in multiple state and regional yield trials during 2001 to 2006. ‘Covington’ produces yields equal to ‘Beauregard’, a dominant sweetpotato variety produced in the United States, but it is typically 5 to 10 days later in maturity. ‘Covington’ typically sizes its storage roots more evenly than ‘Beauregard’ resulting in fewer jumbo class roots and a higher percentage of number one roots. Total yields are similar for the two clones with the dry matter content of ‘Covington’ storage roots typically being 1 to 2 points higher than that of ‘Beauregard’. ‘Covington’ is resistant to fusarium wilt [Fusarium oxysporum Schlect. f.sp. batatas (Wollenw.) Snyd. & Hans.], southern root-knot nematode [Meloidogyne incognita (Kofoid & White 1919) Chitwood 1949 race 3], and moderately resistant to streptomyces soil rot [Streptomyces ipomoeae (Person & W.J. Martin) Wakswan & Henrici]. Symptoms of the russet crack strain of Sweet Potato Feathery Mottle Virus have not been observed in ‘Covington’. The flavor of the baked storage roots of ‘Covington’ has been rated as very good by standardized and informal taste panels and typically scores as well or better in this regard when compared with ‘Beauregard’.

scholarly journals Reaction of potential guava rootstocks to Meloidogyne enterolobii

Revista CERES ◽  
2018 ◽  
Vol 65 (3) ◽  
pp. 291-295 ◽  
Author(s):  
Fernando Marcelo Chiamolera ◽  
Antonio Baldo Geraldo Martins ◽  
Pedro Luiz Martins Soares ◽  
Tatiana Pagan Loeiro da Cunha-Chiamolera
Keyword(s):  
Root System ◽  
Fusarium Solani ◽  
Root Rot ◽  
System Development ◽  
Control Treatment ◽  
Root Knot Nematode ◽  
Second Stage ◽  
Root System Development ◽  
Meloidogyne Enterolobii ◽  
Reproduction Factor

ABSTRACT Root-knot nematode Meloidogyne enterolobii is the main phytosanitary problem of guava cultivation in Brazil. Among the strategies to manage the problem, the best prospects are in identifying or developing cultivars or rootstocks that are resistant to this nematode. To identify plants with potential as rootstocks for guava, the reaction of araçá (wild guava) to M. enterolobii was assessed in a greenhouse experiment. Seven araçá species were evaluated (Eugenia stipitata, Psidium acutangulum, P. cattleyanum ‘yellow’, P. friedrichsthalianum, P. guajava var. minor, P. guineense, and Psidium sp.). The plants were inoculated with a suspension of 3,000 eggs of M. enterolobii, using eggplant as control treatment. The parameters fresh root mass, number of eggs and second stage juveniles (J2) per root system, the reproduction factor (RF = Pf/Pi), and araçá reaction were determined during the experiment. RF of the araçá species E. stipitata, P. cattleyanum ‘yellow’, and P. friedrichsthalianum was less than one (RP < 1), therefore resistant to M. enterolobii. The araçá trees had good root system development and the susceptible plants showed many root galls, high number of eggs and J2, and Fusarium solani and Rhizoctonia solani root rot. The araçá species, P. cattleyanum ‘yellow’, P. friedrichsthalianum, and E. stipitata are resistant to M. enterolobii and can be tested as potential guava rootstocks.

scholarly journals Do the stage of plant and initial population of root knot nematode influence on sweet pepper development?

O Biológico ◽  
2020 ◽  
Vol 82 (1) ◽  
pp. 1-10
Author(s):  
Samara A. de Oliveira ◽  
Juliana M. O Rosa ◽  
Juliana Eulálio ◽  
Claudio Marcelo G. de Oliveira
Keyword(s):  
Sweet Pepper ◽  
Initial Population ◽  
Root Knot Nematode ◽  
One Pot ◽  
Leaf Pair ◽  
Final Population ◽  
Randomized Design ◽  
Meloidogyne Enterolobii ◽  
Shoot Weight ◽  
Reproduction Factor

The aim of this study was to investigate the response of three different stages (one, three and five leaf pairs) of sweet pepper (Capsicum annuum cv. Orazio) seedlings to five inoculation levels of Meloidogyne enterolobii (zero (control), 300, 1000, 3000 and 10000) under greenhouse conditions. Each plant was cultivated in one pot filled with 3.8 L of substrate. The test was a completely randomized design with four replications. The plants were assessed 60 days after inoculation, plant shoot weight, final population of nematodes, and reproduction factor were measured. The results were fitted to Seinhorst model: Y = m + (1-m). ZPi –T. The results showed a tolerance limit (T) of 2,500 nematodes for plants with one and three leaf pair, and 8,500 nematodes for the five-leaf pair plant.

scholarly journals Resistance sources to root-knot nematode Meloidogyne enterolobii in Solanum species

2020 ◽  
pp. 303
Author(s):  
Jadir Borges Pinheiro ◽  
Giovani Olegario da Silva ◽  
Jhenef Gomes de Jesus ◽  
Danielle Biscaia ◽  
Raphael Augusto de Castro e Melo
Keyword(s):  
Solanum Species ◽  
Experimental Unit ◽  
Egg Mass ◽  
Root Knot Nematode ◽  
Sources Of Resistance ◽  
Second Stage ◽  
Randomized Design ◽  
Meloidogyne Enterolobii ◽  
Plant Grown ◽  
Reproduction Factor

The objective of this work was to prospect sources of resistance to root-knot nematode Meloidogyne enterolobii in Solanum species with potential to be used as rootstocks for cultivated Solanaceae. Nine accessions of Solanum sessiliflorum, 27 accessions of S. lycocarpum, 21 accessions of S. acanthodes, 22 accessions of S. scinericum and 26 accessions of S. scuticum for resistance to M. enterolobii. Rutgers and Nemadoro tomatoes were used as susceptible and resistant controls, respectively. The experiment was conducted in a greenhouse at Embrapa Vegetables, Brasília-DF, Brazil, in a completely randomized design with six replications. The experimental unit was a represented by a single plant grown in a plastic pot containing 3 L of substrate. 4000 eggs and eventual juveniles of second stage M. enterolobii were inoculated per pot. At 119 days after inoculation, gall index (Gi), egg mass index (EMI), number of eggs per root gram (NE) and reproduction factor (Fr) were evaluated. Data were subjected to analysis of variance and grouping of treatments by Scott-Knott. It was verified that S. acanthodes and S. Lycocarpum are species with high resistance to M. enterolobii, with accessions being classified identified as immune. S. scuticum also has great potential, as several resistant accessions were identified, although some accessions were quite susceptible; whereas for S. subinerme only 4 resistant accessions were identified, although all others presented a reproduction factor much lower than tomato cv. Nemadoro as control; and all evaluated S. sessiliflorum accessions were susceptible.

scholarly journals Host Reactions of Sweetpotato Genotypes to Root-knot Nematodes and Variation in Virulence of Meloidogyne incognita Populations

HortScience ◽  
2002 ◽  
Vol 37 (7) ◽  
pp. 1112-1116 ◽  
Author(s):  
J.C. Cervantes-Flores ◽  
G.C. Yencho ◽  
E.L. Davis
Keyword(s):  
North Carolina ◽  
Ipomoea Batatas ◽  
Nematode Species ◽  
Host Race ◽  
Root Knot Nematode ◽  
Root Knot Nematodes ◽  
Differential Reaction ◽  
Geographical Regions ◽  
Host Status ◽  
Soil Mix

Sweetpotato [Ipomoea batatas (L.) Lam.] genotypes were evaluated for resistance to North Carolina root-knot nematode populations: Meloidogyne arenaria (Neal) Chitwood races 1 and 2; M. incognita (Kofoid & White) Chitwood races 1, 2, 3, and 4; and M. javanica (Treub) Chitwood. Resistance screening was conducted using 150-cm3 Conetainers containing 3 sand: 1 soil mix. Nematode infection and reproduction were assessed as the number of egg masses produced by root-knot nematodes per root system. Host suitability for the root-knot nematode populations differed among the 27 sweetpotato genotypes studied. Five genotypes (`Beauregard', L86-33, PDM P6, `Porto Rico', and `Pelican Processor') were selected for further study based on their differential reaction to the different root-knot nematodes tested. Two African landraces (`Tanzania' and `Wagabolige') were also selected because they were resistant to all the nematode species tested. The host status was tested against the four original M. incognita races, and an additional eight populations belonging to four host races, but collected from different geographical regions. The virulence of root-knot nematode populations of the same host race varied among and within sweetpotato genotypes. `Beauregard', L86-33, and PDM P6 were hosts for all 12 M. incognita populations, but differences in the aggressiveness of the isolates were observed. `Porto Rico' and `Pelican Processor' had different reactions to the M. incognita populations, regardless of the host race. Several clones showed resistance to all M. incognita populations tested. These responses suggest that different genes could be involved in the resistance of sweetpotato to root-knot nematodes. The results also suggest that testing Meloidogyne populations against several different sweetpotato hosts may be useful in determining the pathotypes affecting sweetpotato.

Identification of Sweetpotato Germplasm Resistant to Pathotypically Distinct Isolates of Meloidogyne enterolobii from the Carolinas

Plant Disease ◽  
2021 ◽  
Author(s):  
William Rutter ◽  
Phil Wadl ◽  
John David Mueller ◽  
Paula Agudelo
Keyword(s):  
United States ◽  
Ipomoea Batatas ◽  
Germplasm Collection ◽  
Resistance Breeding ◽  
The United States ◽  
Root Knot Nematode ◽  
Breeding Programs ◽  
Nematode Reproduction ◽  
Pathogenic Variants ◽  
Meloidogyne Enterolobii

Meloidogyne enterolobii (syn. mayaguensis) is an emergent species of root-knot nematode that has become a serious threat to sweetpotato (Ipomoea batatas) production in the southeastern United States. The most popular sweetpotato cultivars grown in this region are highly susceptible to M. enterolobii. As a result, this pest has spread across most of the sweetpotato growing counties in the Carolinas, threatening the industry as well as other crops in the region. The development and release of new sweetpotato cultivars with resistance to M. enterolobii would help to manage and slow the spread of this pest. To support sweetpotato resistance breeding efforts, 93 accessions selected from the USDA germplasm collection and breeding programs in the United States were screened to identify 19 lines with strong resistance to M. enterolobii. The resistance in these accessions was tested against two M. enterolobii isolates that were collected from sweetpotato production fields in the Carolinas. These isolates were found to have distinct pathotypes, with galling and nematode reproduction differences observed on cotton as well as sweetpotato. This study is the first report of intraspecific pathotypic variation in M. enterolobii and identifies sweetpotato germplasm with resistance against both pathogenic variants of this nematode.

Oat, wheat and sorghum cultivars for the management of Meloidogyne enterolobii

Nematology ◽  
2018 ◽  
Vol 20 (2) ◽  
pp. 169-173 ◽  
Author(s):  
Andressa Lima de Brida ◽  
Bárbara Monteiro de Castro e Castro ◽  
José Cola Zanuncio ◽  
José Eduardo Serrão ◽  
Silvia Renata Siciliano Wilcken
Keyword(s):  
Sorghum Bicolor ◽  
Crop Rotation ◽  
Avena Sativa ◽  
Nematode Species ◽  
Root Knot Nematode ◽  
Egg Masses ◽  
Meloidogyne Enterolobii ◽  
Reproduction Factor

Meloidogyne enterolobii, reported in different regions of Brazil, is a polyphagous nematode parasitising plants resistant to other root-knot nematode species. This study evaluated the resistance of six cultivars of Avena sativa, seven cultivars of Triticum aestivum and 13 hybrids of Sorghum bicolor to M. enterolobii. The experiment was conducted in a glasshouse. The soil was autoclaved and infested with 5000 eggs of M. enterolobii. The tomato ‘Rutgers’ was used as the susceptible standard to this nematode. The indices of galls, egg masses, and reproduction factor of M. enterolobii were evaluated 60 days after inoculation. This nematode did not reproduce in any of the genotypes considered resistant. The oat, wheat and sorghum cultivars studied may be recommended for crop rotation in areas infested with M. enterolobii.

scholarly journals Efficient Evaluation of Resistance to Three Root-knot Nematode Species in Selected Sweetpotato Cultivars

HortScience ◽  
2002 ◽  
Vol 37 (2) ◽  
pp. 390-392 ◽  
Author(s):  
J.C. Cervantes-Flores ◽  
G.C. Yencho ◽  
E.L. Davis
Keyword(s):  
Root System ◽  
Ipomoea Batatas ◽  
Nematode Species ◽  
Nematode Infection ◽  
Root Knot Nematode ◽  
Root Necrosis ◽  
Dependent Variables ◽  
Screening Efficiency ◽  
Nematode Eggs ◽  
Race 2

Five sweetpotato [Ipomoea batatas (L.) Lam.] cultivars (`Beauregard', `Excel', `Jewel', `Hernandez', and `Porto Rico') were evaluated for resistance to three root-knot nematode species: Meloidogyne arenaria (Neal) Chitwood (race 2), M. incognita (Kofoid & White) Chitwood (race 3), and M. javanica (Treub) Chitwood. Resistance screening efficiency was assessed in both 400-cm3 square pots and 150-cm3 Conetainers™. Nematode infection was assessed as the percentage of root system galled, percentage of root system necrosis, and the number of nematode eggs produced per gram of root tissue. Means of these dependent variables were not different (P ≤ 0.05) between container types, with Conetainers™ being more efficient to use. Root necrosis was not related to nematode infection, but was significant among cultivars (P = 0.0005). The resistance responses of the cultivars differed depending on the nematode species. All five cultivars were resistant to M. arenaria race 2. `Hernandez', `Excel', and `Jewel' were also resistant to M. incognita race 3 and M. javanica.

Distribution of Meloidogyne enterolobii in Eastern North Carolina and Comparison of Four Isolates

2020 ◽  
Vol 21 (2) ◽  
pp. 91-96 ◽  
Author(s):  
Tanner Schwarz ◽  
Chunying Li ◽  
Weimin Ye ◽  
Eric Davis
Keyword(s):  
North Carolina ◽  
Pcr Primers ◽  
The United States ◽  
Vegetable Crops ◽  
Root Knot Nematode ◽  
North Carolina Department ◽  
The North ◽  
Meloidogyne Enterolobii ◽  
Consumer Services ◽  
Eastern Half

The guava root-knot nematode (RKN), Meloidogyne enterolobii, is a particularly aggressive pathogen with limited known distribution in the United States. In 2011, M. enterolobii was identified on field crops in North Carolina for the first time. In collaboration with the North Carolina Department of Agriculture and Consumer Services Nematode Assay Laboratory, RKN-positive samples from the eastern half of North Carolina submitted to the laboratory were analyzed for Meloidogyne species identification using polymerase chain reaction (PCR) of individual nematodes. PCR primers specific for Meloidogyne incognita, M. javanica, M. arenaria, M. hapla, and M. enterolobii were used to analyze DNA from 203 RKN-positive samples representing a variety of field and vegetable crops grown in counties in the eastern half of North Carolina. M. incognita was the predominant species identified (32% of samples), and M. enterolobii was identified in 6% of samples including ones from sweetpotato, tobacco, and soybean crops. New detections of M. enterolobii were found in Nash, Greene, Sampson, and Harnett counties in addition to the previously identified locations in Johnston, Wayne, Columbus, and Wilson counties. Four isolates of M. enterolobii populations were collected from soybean and sweetpotato crops in Johnston, Greene, and Wilson counties and reared on ‘Rutgers’ tomato plants in the greenhouse. Potential differences in virulence among the four M. enterolobii populations were not detected in greenhouse infection assays on six selected resistant and susceptible sweetpotato genotypes in two independent tests.

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