Influence of Citrullus lanatus var. citroides Rootstocks and Their F1 Hybrids on Yield and Response to Root-knot Nematode, Meloidogyne incognita, in Grafted Watermelon

Southern root-knot nematodes (Meloidogyne incognita) are an important re-emerging pest of watermelon in the United States and worldwide. The re-emergence of root-knot nematodes (RKNs) in watermelon and other cucurbits is largely the result of the intensive cultivation of vegetable crops on limited agricultural lands coupled with the loss of methyl bromide for pre-plant soil fumigation, which has been the primary method for control of RKNs and many soilborne diseases of cucurbits and other vegetable crops for several decades. One alternative for managing RKN in watermelon is the use of resistant rootstocks for grafted watermelon. We have developed several RKN-resistant Citrullus lanatus var. citroides lines (designated RKVL for Root-Knot Vegetable Laboratory), which have shown promise as rootstocks for grafted watermelon. In 2011 and 2012, we demonstrated that F1 hybrids derived from our selected RKVL lines exhibited resistance to RKN that was equal to or greater than that of the parental RKVL lines when grown in fields highly infested with M. incognita. In 2011, although significant differences were not observed among rootstocks, the F1 hybrids produced slightly higher yields compared with the selected parental lines. Among the selected parental lines, RKVL 318 produced high yields in both years. In 2011, three of four RKVL parental lines and all four of their F1 hybrids produced greater (P < 0.05) fruit yields than self-grafted ‘Tri-X 313’, ‘Emphasis’ bottle gourd, and ‘Strong Tosa’ squash hybrid. In 2012, three RKVL F1 hybrid lines produced higher yields than the selected parents. Overall, these F1 hybrids were vigorous and should provide useful genetic material for selection and development of robust RKN-resistant C. lanatus var. citroides rootstock lines.

Download Full-text

Grafting for Management of Southern Root-Knot Nematode, Meloidogyne incognita, in Watermelon

Plant Disease ◽

10.1094/pdis-09-09-0640 ◽

2010 ◽

Vol 94 (10) ◽

pp. 1195-1199 ◽

Cited By ~ 46

Author(s):

Judy A. Thies ◽

Jennifer J. Ariss ◽

Richard L. Hassell ◽

Steve Olson ◽

Chandrasekar S. Kousik ◽

...

Keyword(s):

Meloidogyne Incognita ◽

Citrullus Lanatus ◽

Bottle Gourd ◽

Cucurbita Moschata ◽

Lagenaria Siceraria ◽

Root Knot Nematode ◽

Root Knot Nematodes ◽

Germplasm Line ◽

Southern Root Knot Nematode

Four bottle gourd (Lagenaria siceraria) cultivars, one squash (Cucurbita moschata × C. maxima) hybrid, five wild watermelon (Citrullus lanatus var. citroides) germplasm lines, and one commercial wild watermelon (C. lanatus var. citroides) cultivar were evaluated as rootstocks for cultivated watermelon (C. lanatus var. lanatus) in fields infested with the southern root-knot nematode (Meloidogyne incognita) in Charleston, SC in 2007 and 2008, and in Quincy, FL in 2008. Commercial watermelon ‘Fiesta’ (diploid seeded) and ‘Tri-X 313’ (triploid seedless) scions were grafted onto the rootstocks in 2007 and 2008, respectively. In 2007, the plants grafted on rootstock from the wild watermelon germplasm line RKVL 318 had significantly less (P < 0.05) root galling than nongrafted ‘Fiesta’ watermelon or plants with the squash hybrid or bottle gourd rootstocks. In 2008, ‘Fiesta’ plants with rootstocks from all five wild watermelon germplasm lines and the commercial watermelon rootstock had significantly less (P < 0.05) root galling than plants with the squash hybrid or bottle gourd rootstocks. Root galling of the squash hybrid and bottle gourd rootstocks was severe (78 to 99%) in both years. Root galling for nongrafted ‘Fiesta’ and ‘Tri-X 313’ watermelon was 36 and 50%, respectively. Root galling for the wild watermelon germplasm lines ranged from 11 to 34% and 36 to 44% in 2007 and 2008, respectively. Wild watermelon germplasm lines derived from C. lanatus var. citroides were identified that may be useful as resistant rootstocks for managing root-knot nematodes in watermelon.

Download Full-text

Genome expression dynamics reveals parasitism regulatory landscape of the root-knot nematode Meloidogyne incognita and a promoter motif associated with effector genes

10.1101/2021.04.02.438169 ◽

2021 ◽

Author(s):

Martine Da Rocha ◽

Caroline Bournaud ◽

Julie Dazeniere ◽

Peter Thorpe ◽

Clement Pellegrin ◽

...

Keyword(s):

Gene Expression ◽

Meloidogyne Incognita ◽

Life Stage ◽

Regulation Of Gene Expression ◽

Root Knot Nematode ◽

Root Knot Nematodes ◽

Control Of Gene Expression ◽

Precise Control ◽

Effector Genes ◽

Spatio Temporal

Root-knot nematodes are the major contributor to the crop losses caused by nematodes. Root-knot nematodes secrete effectors into the plant, derived from two sets of pharyngeal gland cells, to manipulate host physiology and immunity. Successful completion of the life cycle, involving successive molts from egg to adult, covers morphologically and functionally distinct stages and will require precise control of gene expression, including effectors. The details of how root-knot nematodes regulate transcription remain sparse. Here, we report a life stage-specific transcriptome of Meloidogyne incognita. Combined with an available annotated genome, we explore the spatio-temporal regulation of gene expression. We reveal gene expression clusters and predicted functions that accompany the major developmental transitions. Focusing on effectors, we identify a putative cis-regulatory motif associated with expression in the dorsal glands: providing an insight into effector regulation. We combine the presence of this motif with several other criteria to predict a novel set of putative dorsal gland effectors. Finally, we show this motif, and thereby its utility, is broadly conserved across the Meloidogyne genus and termed it Mel-DOG. Taken together, we provide the first genome-wide analysis of spatio-temporal gene expression in a root-knot nematode, and identify a new set of candidate effector genes that will guide future functional analyses.

Download Full-text

Application of Biogas Digestate with Rice Straw Mitigates Nitrate Leaching Potential and Suppresses Root-Knot Nematode (Meloidogyne incognita)

Agronomy ◽

10.3390/agronomy9050227 ◽

2019 ◽

Vol 9 (5) ◽

pp. 227 ◽

Cited By ~ 4

Author(s):

Yuexi Wang ◽

Seiya Chikamatsu ◽

Tuya Gegen ◽

Kozue Sawada ◽

Koki Toyota ◽

...

Keyword(s):

Rice Straw ◽

Nitrate Leaching ◽

Meloidogyne Incognita ◽

Application Rate ◽

Pig Manure ◽

Test Plant ◽

Root Knot Nematode ◽

Root Knot Nematodes ◽

Leaching Potential ◽

Biogas Digestate

This study investigated the effects of biogas digestate application to soil with rice straw on nitrate leaching potential and nematicidal activity toward root-knot nematodes Meloidogyne incognita. The following seven treatments were set up: (i) control (CONT); (ii) chemical fertilizer (CF); (iii) wet biogas digestate derived from pig manure (WBD); (iv) and (v) dry biogas digestate derived from a mixture of pig manure and rice straw at an initial C/N ratio of 20 and 30 (DBD20 and DBD30); (vi) and (vii) DBD20 mixed with rice straw to adjust the C/N ratio to 16 (Mix1) and 30 (Mix2), respectively. The application rate of CF and digestates was adjusted to 200 mg N kg−1 soil based on the inorganic ammonium nitrogen contents. Nitrate contents readily increased in all the treatments with incubation, except for Mix2, and those at day 90 were decreased with increasing initial labile C contents. Garden balsam was grown as a test plant for root-knot nematodes using the soils at day 90 and the results showed that the gall index was significantly lower in Mix2 and Mix1 than in CF. These results suggest that dry digestate mixed with rice straw might have potential for lower nitrate leaching and nematicidal properties.

Download Full-text

Comparison of host recognition, invasion, development and reproduction of Meloidogyne graminicola and M. incognita on rice and tomato

Nematology ◽

10.1163/138855410x528262 ◽

2011 ◽

Vol 13 (5) ◽

pp. 509-520 ◽

Cited By ~ 19

Author(s):

Tushar K. Dutta ◽

Stephen J. Powers ◽

Brian R. Kerry ◽

Hari S. Gaur ◽

Rosane H.C. Curtis

Keyword(s):

Meloidogyne Incognita ◽

Host Recognition ◽

Cortical Region ◽

Root Knot Nematode ◽

Root Tips ◽

Root Knot Nematodes ◽

Tomato Plants ◽

Meloidogyne Graminicola ◽

Second Stage ◽

Tomato Roots

AbstractThe rice root-knot nematode Meloidogyne graminicola normally infects rice, wheat and several other graminaceous plants. Meloidogyne incognita is a serious pest of dicotyledonous crops, although it can infect and reproduce on some cereals. This paper demonstrates and compares host recognition, development and reproduction of these two species of root-knot nematodes on rice and tomato plants. Attraction bioassays in pluronic gel clearly showed that M. incognita preferred tomato roots to rice or mustard roots, whilst M. graminicola was more attracted towards rice compared with tomato or mustard roots. Based on the attraction data from this study, it can be hypothesised that either: i) the blend of attractants and repellents are different in good and poor hosts; or ii) relatively long-range attractants, together with shorter-range repellents, might affect nematode movement patterns. Some host specific attractants might also be involved. Meloidogyne incognita was able to invade and develop to adult female but did not produce eggs in rice roots. By contrast, M. graminicola developed and reproduced faster on both rice and tomato plants compared with M. incognita. Nevertheless, second-stage juveniles of both these root-knot nematodes showed a similar pattern of distribution inside the roots, preferring to accumulate at the root tips of rice or in the vascular cylinder and cortical region of tomato.

Download Full-text

Combining Ability and Heritability of Resistance to Early and Late Leafspot of Peanut1

Peanut Science ◽

10.3146/i0095-3679-13-1-4 ◽

1986 ◽

Vol 13 (1) ◽

pp. 10-14 ◽

Cited By ~ 8

Author(s):

W. F. Anderson ◽

J. C. Wynne ◽

C. C. Green ◽

M. K. Beute

Keyword(s):

Combining Ability ◽

Additive Genetic Variance ◽

Rank Correlation ◽

F1 Hybrids ◽

Cercospora Arachidicola ◽

F1 Hybrid ◽

Detached Leaf ◽

F2 Population ◽

Parental Lines ◽

High Level

Abstract Four parental lines with resistance to early leafspot caused by Cercospora arachidicola Hori and four parental lines with resistance to late leafspot caused by Cercosporidium personatum (Berk. & Curt.) Deighton and the F1 hybrid progeny from crosses between the two groups of parents were evaluated for resistance to both leafspot diseases in the greenhouse using a detached leaf technique. The subsequent F2 plants of all crosses were evaluated in the field for resistance to early leafspot in order to estimate combining ability effects for components of partial resistance and to identify parents useful in developing lines resistant to both diseases. General combining ability, attributed largely to additive genetic variance, accounted for the largest portion of the variability among the F1 and F2 generations for most parameters of resistance to both early and late leafspots. Reciprocal effects and heterosis toward the susceptible parents were also significant for parameters of resistance to the two pathogens. GP-NC 343 and FESR 5-P2-B1 were the best parents for incorporating genes for resistance to both early and late leafspots. Progenies of NC 17090 had a high level of resistance to late leafspot in detached leaf tests and progeny of PI 350680 had reduced defoliation from early leafspot in the field. Broad-sense heritabilities ranged from 0.2 to 0.4 for parameters of resistance to early leafspot estimated from the pooled variances of F2 plants of all crosses planted in the field. Parameters of resistance evaluated in the greenhouse for F1 hybrids were compared to parameters evaluated in the field for the F2 population by rank correlation of entry means. Latent period and sporulation of the fungus on detached leaves of F1 generation plants correlated (r = −0.46 and 0.54, respectively) with defoliation of F2 plants in the field.

Download Full-text

Effect of Southern Root-knot Nematode (Meloidogyne incognita race 3) on Corn Yields in Alabama

Plant Health Progress ◽

10.1094/php-2008-0910-01-rs ◽

2008 ◽

Vol 9 (1) ◽

pp. 11 ◽

Cited By ~ 1

Author(s):

K. L. Bowen ◽

A. K. Hagan ◽

H. L. Campbell ◽

S. Nightengale

Keyword(s):

Meloidogyne Incognita ◽

Root Knot Nematode ◽

Management Decisions ◽

Root Knot Nematodes ◽

Percent Loss ◽

Stage Juvenile ◽

Risk Thresholds ◽

Southern Root Knot Nematode ◽

Soil Losses ◽

Corn Grain

In Alabama and other southeastern states, corn is frequently planted in rotation with cotton and peanut in order to minimize soil-borne pest problems. Even in areas where peanut is not grown, corn is increasingly being planted in rotation with cotton. However, one root-knot nematode, Meloidogyne incognita race 3, causes damage to both cotton and corn. In this study, we determined levels of corn grain loss when southern root-knot nematodes are present in soil. Losses were 3.8 to 11.4% based on preceding years' counts and 2.2 to 7.0% with current years' counts for every 100 2nd-stage juvenile root-knot nematodes in 100 cm ≥ of soil. Knowledge of the percent loss in corn grain due to southern rootknot nematode populations can provide additional guidance for use of risk thresholds when growers are making management decisions. Accepted for publication 21 June 2008. Published 10 September 2008.

Download Full-text

First Report of the Root-Knot Nematode (Meloidogyne incognita) on Curcuma longa in the United States

Plant Disease ◽

10.1094/pdis-03-17-0409-pdn ◽

2017 ◽

Vol 101 (10) ◽

pp. 1826-1826

Author(s):

M. Hall ◽

K. Lawrence ◽

W. Groover ◽

D. Shannon ◽

T. Gonzalez

Keyword(s):

United States ◽

Meloidogyne Incognita ◽

Curcuma Longa ◽

The United States ◽

Root Knot Nematode ◽

First Report

Download Full-text

First Report of the Root-Knot Nematode Meloidogyne floridensis on Tomato (Lycopersicon esculentum) in Florida

Plant Disease ◽

10.1094/pd-89-0527b ◽

2005 ◽

Vol 89 (5) ◽

pp. 527-527

Author(s):

G. T. Church

Keyword(s):

Lycopersicon Esculentum ◽

Field Experiments ◽

The United States ◽

The State ◽

Bromophenol Blue ◽

Root Knot Nematode ◽

Fresh Market ◽

Root Knot Nematodes ◽

First Report ◽

Meloidogyne Spp

The state of Florida is the largest producer of fresh market tomato (Lycopersicon esculentum L.) in the United States with 2003 yields of 634 million kg on 17,700 ha valued at 516 million dollars. Effective crop management is essential for production of vegetables in Florida because of the presence of intense pest pressure. The identification of the pests present is the first step in the development of a successful IPM (integrated pest management) program. Root-knot nematodes (Meloidogyne spp.) are common nematodes that parasitize vegetables in Florida and cause significant yield reductions when not properly managed. In 2003 field experiments, soil was collected from two research farms in Saint Lucie and Seminole counties in Florida. Galling caused by root-knot nematode was observed on tomato at both locations. Since females suitable for identification are difficult to obtain from field-grown roots, field soil was placed in pots in the greenhouse and planted with Lycopersicon esculentum cv. Rutgers. Standard morphological techniques, differential host tests, and isozyme phenotypes were used in nematode identification. Female root-knot nematodes were extracted from tomato roots and placed in extraction buffer (10% wt/vol sucrose, 2% vol/vol Triton X-100, 0.01% wt/vol bromophenol blue). The females were crushed, loaded on a polyacrylamide gel, and separated by electrophoresis using the PhastSystem (Amersham Biosciences, Piscataway, NJ). The activities of malate dehydrogenase and esterase enzymes were detected using standard techniques. Isozyme phenotypes consistent with Meloidogyne incognita (Kofoid and White) Chitwood and M. javanica (Treub) Chitwood as well as with the newly described M. floridensis Handoo (1) were observed at both locations. To our knowledge, this is the first report of M. floridensis naturally occurring on tomato in Florida. The identification and distribution of M. floridensis in vegetable production fields is important for disease management throughout the state since the host range is likely different from other Meloidogyne spp. Reference: (1) Z. A. Handoo et al. J. Nematol. 36:20, 2004.

Download Full-text

Reaction of weeds, found in vegetable production areas, to root-knot nematodes Meloidogyne incognita and M. enterolobii

Horticultura Brasileira ◽

10.1590/s0102-053620190413 ◽

2019 ◽

Vol 37 (4) ◽

pp. 445-450

Author(s):

Jadir B Pinheiro ◽

Giovani Olegario da Silva ◽

Danielle Biscaia ◽

Amanda G Macedo ◽

Núbia Maria Correia

Keyword(s):

Meloidogyne Incognita ◽

Great Majority ◽

Egg Mass ◽

Vegetable Production ◽

Vegetable Crops ◽

Weed Species ◽

Root Knot Nematodes ◽

Hyptis Suaveolens ◽

Race 1 ◽

Production Areas

ABSTRACT Root-knot nematodes cause great damage to vegetable crops in Brazil, besides having a large range of host plants, such as weeds. Weeds can maintain the inoculums or even favor the multiplication of these nematodes. In this study we evaluated the reaction of selected weed species, present in a vegetable production area, to root-knot nematodes Meloidogyne incognita and M. enterolobii. The trials were conducted in a greenhouse at Embrapa Hortaliças, Brasília-DF, in a completely randomized design with six replicates. Fifteen weed species were evaluated for M. incognita race 1, and 16 weed species were evaluated for M. enterolobii. Two tomato cultivars were evaluated as resistance and susceptibility standards. Gall index (IG), egg mass index (IMO), number of eggs per gram of roots (eggs/g roots) and reproduction factor (FR) were evaluated. M. enterolobii survives and multiplies more easily in weeds collected in vegetable production areas than M. incognita race 1 and, the great majority of weed species evaluated in this study are hosts of both nematode species. Only the species Urena lobata, Sonchus oleraceus, Euphorbia heterophylla, Melampodium perfoliatum and Tagetes sp. were immune to M. incognita race 1. All evaluated species are either hosts or favor the multiplication of M. enterolobii. The species which are the most susceptible to M. incognita race 1, and therefore require greater control of crops infected by this nematode are Ipomoea nil, I. triloba and Eleusine indica, and for M. enterolobii are I. nil, Solanum americanum, Hyptis suaveolens, Portulaca oleracea, I. triloba and Euphorbia heterophylla.

Download Full-text

Correlation of yield and heterosis of maize hybrids and their parental lines with genetic distance based on SSR markers

Genetika ◽

10.2298/gensr1202399d ◽

2012 ◽

Vol 44 (2) ◽

pp. 399-408 ◽

Cited By ~ 1

Author(s):

Snezana Mladenovic-Drinic ◽

Marija Kostadinovic ◽

Danijela Ristic ◽

Milan Stevanovic ◽

Zoran Camdzija ◽

...

Keyword(s):

Grain Yield ◽

Genetic Distance ◽

Ssr Markers ◽

F1 Hybrids ◽

F1 Hybrid ◽

Maize Hybrids ◽

Average Value ◽

Parental Inbred ◽

The Mean ◽

Parental Lines

The yield, grain yield heterosis and genetic distance based on SSR markers were analyzed in eight maize hybrids and their parental lines. The mean grain yield of all F1 hybrids was 11.37 tha-1. The F1 hybrid from the crosses between L4xL6 gave the highest grain yield of 12.12 tha-1. For the mid parent heterosis (MPH) grain yields of the F1 hybrids, the data showed the average value of 164.25%, and ranged from 136.72% (L4xL6) to 218.07% (L8xL2), and for better parent heterosis (BPH) from 100.70% (H4) to 212.60% (H2), averaged 137.36%. The average genetic distance among parental inbred lines of analyzed hybrids was 0.58 with a range from 0.55 to 0.61. The GD showed a positive correlation with the grain yield of the F1 hybrids (0.22), as well as with MPH and BPH, with the values of 0.12 and 0.45, respectively.

Download Full-text