Identification and Evaluation of Additional Sources of Resistance to Peanut Root-knot Nematode in Arachis hypogaea L.1

1996 ◽  
Vol 23 (2) ◽  
pp. 91-94 ◽  
Author(s):  
C. Corley Holbrook ◽  
James P. Noe ◽  
Michael G. Stephenson ◽  
William F. Anderson

Abstract The root-knot nematode (Meloidogyne arenaria race 1) causes significant economic losses throughout the peanut (Arachis hypogaea) production areas of the southern U.S. Chemicals for control of this pest are becoming increasingly limited, and there are no peanut cultivars with resistance. Seven moderately resistant plant introductions have been identified; however, less than 25% of the germplasm collection has been examined for resistance based on nematode reproduction. The objectives of this work were to examine an additional 1000 plant introductions for resistance to the peanut root-knot nematode and to compare the most resistant introductions to previously reported sources of resistance. Preliminary greenhouse screening trials were conducted to rate severity of root galling and amount of egg mass production. Seventeen accessions were selected based on a mean egg mass rating of less than or equal to three. These selections were reevaluated in additional greenhouse and field experiments to quantify levels of resistance and to directly compare these sources of resistance to those previously reported. Eight accessions had a significantly higher level of resistance (lower egg mass rating) than Florunner; however, none had a significantly higher level of resistance than those previously reported. Results of this study identified additional sources of resistance which may provide unique genes for resistance. In addition, two of these new sources of resistance (PI 298848 and PI 311265) exhibited significantly higher yield than those previously identified when grown in soil heavily infested with M. arenaria.

1992 ◽  
Vol 19 (1) ◽  
pp. 35-37 ◽  
Author(s):  
C. Corley Holbrook ◽  
James P. Noe

Abstract The peanut root-knot nematode [Meloidogyne arenaria (Neal) Chitwood race 1] causes significant economic losses throughout the peanut (Arachis hypogaea L.) production area of the southern United States. Chemicals for control of this pest are becoming increasingly limited, and there are no known sources of resistance within the U. S. A. hypogaea collection. The objectives of this research were to screen 1,321 plant introductions for resistance or hypersusceptibility based on egg-mass ratings in greenhouse tests and to conduct more intensive greenhouse studies of selected genotypes to evaluate this method for identifying resistance to the peanut root-knot nematode. Twenty-seven genotypes with low and eight genotypes with high egg-mass ratings were selected and reevaluated in a more intensive greenhouse experiment. Seventeen of the low selections supported fewer (P≤0.05) egg masses, and seven supported less egg production per gram of fresh root weight than Florunner. Three selections for high egg-mass ratings supported more nematode eggs per plant than the cultivar Florunner and had a greater host efficiency. One of these genotypes supported more nematode eggs per gram of fresh root weight than Florunner. These results show that resistance to M. arenaria exists in the cultivated peanut species and can be selected by rating egg-mass production on greenhouse-grown plants.


2001 ◽  
Vol 28 (2) ◽  
pp. 80-84 ◽  
Author(s):  
C. C. Holbrook ◽  
T. G. Isleib

Abstract The U.S. maintains a large (> 8000 accessions) and genetically diverse collection of peanut (Arachis hypogaea L.) germplasm. It is costly to screen all accessions within this collection for traits that could be useful in cultivar development. The objective of this research was to identify countries of origin that are rich sources of resistance to important peanut diseases. This would allow peanut breeders to focus their efforts on smaller subsets of the germplasm collection. Accessions in the peanut core collection were evaluated for resistance to late (Cercosporidium personatum Berk. & M. A. Curtis) and early (Cercospora arachidicola Hori) leaf spot, tomato spotted wilt Tospovirus (TSWV), the peanut root-knot nematode [Meloidogyne arenaria (Neal) Chitwood race 1], and Cylindrocladium black rot (CBR)[Cylindrocladium crotalarie (Loos) Bell & Sobers]. These data then were examined to determine if genes for resistance clustered geographically. Several geographical areas that appear to be rich sources for disease-resistant genes were identified. China had a relatively large number of accessions with resistance to the peanut root-knot nematode. Peru appeared to be a rich source of material with resistance to CBR. Resistance to late leaf spot was more frequent than expected in accessions from Bolivia and Ecuador. Bolivia was also a valuable source of resistance to early leaf spot. Early leaf spot resistance also was more prevalent than expected in accessions from India, Nigeria, and Sudan. India, Israel, and Sudan were valuable origins for material with resistance to TSWV. Accessions with multiple disease resistance were most common in India, Mozambique, and Senegal. This information should enable plant breeders to utilize more efficiently the genes for disease resistance that are available in the U.S. germplasm collection.


HortScience ◽  
1994 ◽  
Vol 29 (6) ◽  
pp. 678-679 ◽  
Author(s):  
Richard L. Fery ◽  
Philip D. Dukes ◽  
Judy A. Thies

A series of greenhouse and field studies was conducted over 9 years to characterize three new sources of resistance in cowpea [Vigna unguiculata (L.) Walp.] to the southern root-knot nematode [Meloidogyne incognita (Kofoid & White) Chitwood] and to determine if the resistances are conditioned by genes allelic to the Rk root-knot nematode resistance gene in `Mississippi Silver'. Three plant introductions (PI), PI 441917, PI 441920, and PI 468104, were evaluated for reaction to M. incognita in four greenhouse tests, and in every test each PI exhibited less galling, egg mass formation, or egg production than `Mississippi Silver'. F2 populations of the crosses between `Mississippi Silver' and each of the three resistant PIs were also evaluated for root-knot nematode resistance in a greenhouse test. None of the F2 populations segregated for resistance, indicating that PI 441917, PI 441920, and PI 468104 each has a gene conditioning resistance that is allelic to the Rk gene in `Mississippi Silver'. Our observations on the superior levels of resistances exhibited by PI 441917, PI 441920, and PI 468104 suggest that the allele at the Rk locus in these lines may not be the Rk allele, but one or more alleles that condition a superior, dominant-type resistance. The availability of additional dominant alleles would broaden the genetic base for root-knot nematode resistance in cowpea.


HortScience ◽  
2006 ◽  
Vol 41 (3) ◽  
pp. 520A-520
Author(s):  
J. A. Thies ◽  
A. Levi

Root-knot nematodes (Meloidogyne incognita, M. arenaria, and M. javanica) cause severe damage to watermelon and resistance has not been identified in any watermelon cultivar. In greenhouse tests, we evaluated 265 U.S. plant introductions (PIs) for nematode resistance (based on root galling and nematode reproduction), and identified 22 PIs of Citrullus lanatus var. citroides as moderately resistant to M. arenaria race 1. In subsequent tests, these 22 PIs exhibited low to moderate resistance to M. incognita race 3 and M. arenaria race 2. Three watermelon (C. lanatus var. lanatus) cultivars (Charleston Gray, Crimson Sweet, and Dixie Lee), three C. colocynthis PIs, and four C. lanatus var. citroides PIs, all previously shown to be susceptible to M. arenaria race 1, were susceptible to M. incognita race 3 and M. arenaria race 2. The C. lanatus var. citroides PIs that are most resistant to both M. incognita and M. arenaria should be useful sources of resistance for developing root-knot nematode resistant watermelon cultivars.


Author(s):  
Jadir Borges Pinheiro ◽  
Giovani Olegario da Silva ◽  
Jhenef Gomes de Jesus ◽  
Danielle Biscaia ◽  
Raphael Augusto de Castro e Melo

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.


2022 ◽  
Vol 12 ◽  
Author(s):  
Carolina Ballén-Taborda ◽  
Ye Chu ◽  
Peggy Ozias-Akins ◽  
C. Corley Holbrook ◽  
Patricia Timper ◽  
...  

Crop wild species are increasingly important for crop improvement. Peanut (Arachis hypogaea L.) wild relatives comprise a diverse genetic pool that is being used to broaden its narrow genetic base. Peanut is an allotetraploid species extremely susceptible to peanut root-knot nematode (PRKN) Meloidogyne arenaria. Current resistant cultivars rely on a single introgression for PRKN resistance incorporated from the wild relative Arachis cardenasii, which could be overcome as a result of the emergence of virulent nematode populations. Therefore, new sources of resistance may be needed. Near-immunity has been found in the peanut wild relative Arachis stenosperma. The two loci controlling the resistance, present on chromosomes A02 and A09, have been validated in tetraploid lines and have been shown to reduce nematode reproduction by up to 98%. To incorporate these new resistance QTL into cultivated peanut, we used a marker-assisted backcrossing approach, using PRKN A. stenosperma-derived resistant lines as donor parents. Four cycles of backcrossing were completed, and SNP assays linked to the QTL were used for foreground selection. In each backcross generation seed weight, length, and width were measured, and based on a statistical analysis we observed that only one generation of backcrossing was required to recover the elite peanut’s seed size. A populating of 271 BC3F1 lines was genome-wide genotyped to characterize the introgressions across the genome. Phenotypic information for leaf spot incidence and domestication traits (seed size, fertility, plant architecture, and flower color) were recorded. Correlations between the wild introgressions in different chromosomes and the phenotypic data allowed us to identify candidate regions controlling these domestication traits. Finally, PRKN resistance was validated in BC3F3 lines. We observed that the QTL in A02 and/or large introgression in A09 are needed for resistance. This present work represents an important step toward the development of new high-yielding and nematode-resistant peanut cultivars.


Plant Disease ◽  
2021 ◽  
Author(s):  
William Rutter ◽  
Phil Wadl ◽  
John David Mueller ◽  
Paula Agudelo

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.


2017 ◽  
Vol 18 (3) ◽  
pp. 146-155 ◽  
Author(s):  
Michael T. McCarville ◽  
Christopher C. Marett ◽  
Mark P. Mullaney ◽  
Gregory D. Gebhart ◽  
Gregory L. Tylka

Management of the soybean cyst nematode (SCN) relies heavily on use of SCN-resistant soybean varieties to limit nematode reproduction and minimize yield loss. For Iowa, almost all SCN-resistant soybean varieties contain SCN resistance genes from a breeding line named Plant Introduction (PI) 88788. Iowa State University conducts experiments to evaluate numerous SCN-resistant and three to four SCN-susceptible soybean varieties in up to nine field experiments across Iowa each year. Data on SCN population density, virulence (SCN race and HG type), soybean yield, precipitation, and growing degree days from more than 25,000 four-row plots in field experiments conducted from 2001 to 2015 were analyzed to determine how these factors affected SCN reproduction and yield. SCN population densities were positively correlated with temperatures and negatively associated with precipitation during the growing seasons, indicating that SCN reproduction was greatest in hot, dry years. Over the years, virulence of SCN populations on PI 88788 increased in the fields in which the experiments were conducted, resulting in increased end-of-season SCN population densities and reduced yields of SCN-resistant soybean varieties with the PI 88788 source of resistance. These results indicate that soybean yield loss caused by SCN on resistant varieties with the common PI 88788 source of resistance likely will increase as virulence of SCN populations increases unless new sources of resistance become widely available and used in the future.


2000 ◽  
Vol 27 (2) ◽  
pp. 78-82 ◽  
Author(s):  
P. Timper ◽  
C. C. Holbrook ◽  
H. Q. Xue

Abstract The peanut root-knot nematode (Meloidogyne arenaria, race 1) is a world-wide pest of peanut (Arachis hypogaea L.). Several moderately resistant genotypes have been identified in the cultivated peanut species. Our objective was to determine the expression of resistance for six of these genotypes. We examined four potential expressions of resistance—(a) fewer second-stage juveniles (J2) penetrate the roots, (b) fewer J2 establish functional feeding sites, (c) slower maturation, and (d) reduced fecundity (eggs per female). Seedlings of the susceptible cultivar Florunner and the resistant genotypes were inoculated with J2 of M. arenaria, and transplanted 3 d later to synchronize nematode development. Penetration was assessed at 3 and 10 d; development at 10 (or 12), 17, 22, and 27 d; and fecundity at 60 d after inoculation. The experiments were conducted in a greenhouse or growth chamber. The number of J2 within the roots was similar in resistant and susceptible peanut after 3 d; however, numbers were lower in two of the resistant genotypes than in Florunner after 10 d. A greater percentage of J2 failed to develop in all of the resistant genotypes (72 to 79%) than in Florunner (50%) after 17 d. Of the J2 that did begin to develop, the rate of maturation and fecundity was similar in resistant and susceptible genotypes. A lack of development indicates that the J2 failed to establish a feeding site. Therefore, the primary expression of resistance in the six peanut genotypes appears to be a reduction in the percentage of J2 that establish a functional feeding site. The decline in J2 after infection may be related to the failure to establish a feeding site.


1990 ◽  
Vol 17 (1) ◽  
pp. 35-38 ◽  
Author(s):  
C. Corley Holbrook ◽  
James P. Noe

Abstract Peanut root-knot nematode (Meloidogyne arenaria (Neal) Chitwood race 1) is a serious pathogen in commercial peanut (Arachis hypogaea L.) production. There is no peanut cultivar with resistance to this nematode. The primary constraint in the development of resistant cultivars has been the absence of identified sources of resistance in A. hypogaea and related wild species. The objective of this study was to examine the wild Arachis spp. collection of the Coastal Plain Experiment Station for sources of resistance to M. arenaria. Thirty-six wild Arachis spp. genotypes were compared with the susceptible cv. Florunner for resistance to M. arenaria reproduction and galling response in two greenhouse tests. A. monticola Krap. et Rig., a member of the second-order gene pool, was the only wild species tested which did not have a gall index and egg-mass index significantly lower than that of A. hypogaea. There was no significant difference between A. monticola and A. hypogaea for the number of eggs per root system or per gram of fresh root weight. In addition, the host efficiency of A. monticola was 3.49, indicating a high level of susceptibility. All genotypes examined from the third-order gene pool species (A. cardenasii Krap. et Greg. nom. nud., A. duranensis Krap. et Greg. nom. nud., A. helodes Martius ex Krap. et Rig. and A. villosa Benth.) exhibited significantly less plant damage and nematode reproduction than A. hypogaea. Except for one A. villosa genotype, all entries from the third-order gene pool exhibited high levels of resistance to M. arenaria based on a host efficiency less than 1.00. All fourth-order gene pool accessions examined (A. burkartii Handro, A. glabrata Benth., and A. hagenbeckii Harms.) exhibited high levels of resistance to M. arenaria. These results indicate that resistance to M. arenaria is prevalent in both the third- and fourth-order gene pools of peanut. These results increase the probability of success in developing peanut cultivars with resistance to M. arenaria since species in the third-order gene pool are cross compatible with A. hypogaea. Based on genetic theory, these results also increase the probability of resistance to M. arenaria in the first-order gene pool. Therefore, further screening for resistance to M. arenaria in A. hypogaea is recommended.


Sign in / Sign up

Export Citation Format

Share Document