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Nematoda. ISSN 2358-436X. This work is licensed under a Creative Commons Attribution International License (https://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Occurrence of Meloidogyne javanica in a noni (Morinda citrifolia L.) crop in Espírito Santo state, BrazilRafael Assis de Souzaa*, Fábio Ramos Alvesa, Antônio Fernando de Souzab, Júlia de Assis Pinheiroa, Ângelo Oliveira Gonçalvesa, Waldir Cintra de Jesus Júniorc and Willian Bucker Moraesa
aUniversidade Federal do Espírito Santo (UFES), Alegre (ES) BrazilbInstituto Federal do Espírito Santo (IFES), Santa Teresa (ES) BrazilcUniversidade Federal de São Carlos (UFSCar), São Carlos (SP) Brazil*[email protected]
HIGHLIGHTS• Meloidogyne javanica was found associated with the noni crop in Espírito Santo state.• This is the first report of this pathosystem in the state.
ABSTRACT: Although there are reports in the literature of root-knot nematodes (Meloidogyne spp.) occurring in association with noni (Morinda citrifolia L.), a plant that helps in the prevention and cure of some human diseases, there are no reports of a nematological survey in the crop in Brazil in commercial areas. The aim of this work was to carry out a survey of phytonematodes associated with noni in commercial plantations in Espírito Santo state, Brazil. The soil and root samples were collected on properties in the counties of Colatina and São Roque do Canaã, the main producers in the upland region of Espírito Santo. The presence of M. javanica was identified in all samples using the technique of esterase isoenzyme electrophoresis. This is the first report of this pathosystem in Espírito Santo State.
Keywords: field survey, root-knot nematodes, forestry species.
Cite as Souza RA, Alves FR, Souza AF, Pinheiro JA, Gonçalves AO, Jesus Jr WC, Moraes WB. Occurrence of Meloidogyne javanica in a noni (Morinda citrifolia L.) crop in Espírito Santo state, Brazil. Nematoda. 2017;4:e062017. http://dx.doi.org/10.4322/nematoda.00617
Received: Apr. 17, 2017 Accepted: Oct. 15, 2017
SCIENTIFIC NOTE
INTRODUCTIONNoni (Morinda citrifolia L.) is a perennial plant from tropical climates, belonging to the Rubiaceae
family. The architecture of its crown is similar to the root system, and the adult plant reaches a height of 3 to 10 m. The noni is native to Southwest Asia, and it is cultivated nowadays in Polynesia, India, the Caribbean, North America, Central America and South America[1, 2]. Although its fruit has been widely consumed in Asia for more than 2000 years, the noni is little known in Brazil, having been introduced there very recently[1, 2].
A number of studies have aimed to prove what folk knowledge claims, which is that the use of noni helps in preventing and curing some illnesses in humans. One of the main components of the fruit is proxeronine, the precursor of the alkaloid xeronine, which activates the catalyzing enzymes of cell metabolism[2]. It is important to highlight the considerable economic interest in M. cintrifolia, since many commercial products are made from it, including beverages (fruit juice), fruit powders (juice made from dried fruits), toiletries (lotions, soaps, etc.), oil (from seeds), and foliar powders (for encapsulation or pills)[3, 4]. Besides, some authors mention M. citrifolia (i.e. cv. Potteri) as a beautiful ornamental plant with small fruits, admired for its bright green foliage.
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Some authors state that one of the most serious phytosanitary problems of the noni crop is the occurrence of Meloidogyne spp. These pathogens have caused crop damage in various areas of noni cultivation around the world, and in parasitized plants, nutritional deficiencies of nitrogen, potassium and iron can be observed[5]. The leaves of attacked plants become pale yellow and suffer from interveinal chlorosis due to the lack of absorption of water and nutrients by the roots. The roots in parasitized plants are characteristically galled, distorted and swollen, so the leaves and branches gradually die as the parasitism becomes more intense, which can lead plants to death[6, 7].
In studies worldwide, a reduction of noni productivity of up to 46.6% and 85%, respectively, was recorded in plants parasitized by M. incongita (Kofold & White) Chitwood in India[6] and by M. arenaria Chitwood in China[7], and this reduction was attributed to the damage that the nematodes caused to the roots.
The first report of root knot nematode in noni in Brazil was in 2015 in Rio Grande do Norte state[8]. The plants severely galled by M. javanica (Treub) presented reduced vigor. Despite this report, it is important to emphasize that information about phytonematodes associated with noni is still scarce, because this crop has only been exploited in Brazil for the past few years.
Due to the scarcity of nematological searches carried out in areas cultivated with noni in Brazil, the present work aimed to identify the species of root-knot nematode associated with noni in the upland region of Espírito Santo state.
MATERIAL AND METHODS
Surveyed areasThe nematological survey was carried out in the main noni-producing counties of Espírito Santo
state. Samples were collected in the counties of São Roque do Canaã and Colatina. The sampled areas were geo-referenced, and the geographical coordinates are presented in Table 1.
Collecting and processing samplesSamples of roots and soil were collected at depths from 0 to 50 cm, following a zigzag route.
On average, 30 subsamples were taken per hectare for each area to constitute a soil and root sample from the rhizosphere of the plant. The samples were placed in plastic bags, labeled and taken for extraction and evaluation.
From each sample, 20 g of roots was taken, then washed in running water, cut using scissors and triturated in a liquidizer for 30 s. Later, the processed material was sieved through 20, 60 and 500 mesh, and the supernatant removed in the last sieve was centrifuged in a sucrose solution[9].
Nematode extraction and countingTo extract the nematodes from the soil, aliquots of 100 cm3 of soil were removed and deposited in a
bucket of water for later homogenization. The supernatant was sieved through 20 and 400 mesh and centrifuged in a sucrose solution[10].
Table 1. Geo-referencing of the areas cultivated with the noni (Morinda citrifolia L.) crop in counties in Espírito Santo state, in which nematological surveys were performed.
Area CountiesAltitude
(m)Longitude
(w)Latitude
(s)Age of the crop
(years)
1 Colatina 83.76 40.650091 19.63823 3
2 São Roque do Canaã 115.243 40.667434 19.73337 4
3 São Roque do Canaã 91.691 40.666090 19.72556 10
4 São Roque do Canaã 119.088 40.667474 19.72519 2
5 São Roque do Canaã 109.475 40.716977 19.68926 3
6 São Roque do Canaã 106.351 40.717477 19.58843 3
7 São Roque do Canaã 117.646 40.717195 19.68671 4
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The aqueous suspensions that resulted from the extraction processes were transferred to a Peters chamber, where nematodes were counted in 1 mL under an optical microscope with light magnification of 10x. The procedure was performed three times and the mean of the counts calculated. The data obtained were used to determine the nematode population densities in the area. The total population of nematodes was obtained by the sum of individuals extracted from soil and roots.
Esterase analysis
The identification of the species of Meloidogyne present in the samples was carried out using the esterase isoenzyme electrophoresis method, following the methodology described by Carneiro & Almeida[11]. The females were extracted directly from the roots to identify the species. From each sample, 10 females were collected for identification, resulting in a total of 70 females analyzed.
RESULTS AND DISCUSSIONThe electrophoresis analysis confirmed the presence of M. javanica associated with the noni crop
(Figures 1, 2). This is the first report of the presence of M. javanica in noni in Espírito Santo state.The largest populations of nematodes were observed in the roots from samples 7, 3 and 4. In soil,
the largest populations were in samples 7 and 5, respectively. Most of the sampled properties are in the county of São Roque do Canaã, located in the northeastern region of the state (Table 1).
Larger populations of M. javanica were observed in more debilitated plants, according to visual observation, in relation to those with lower nematode populations. The roots of severely attacked plants were seen to be deformed and had root galls in clear evidence (Figure 1). Total nematode populations in soil and roots in all the areas evaluated are shown in Table 2.
Figure 1. (a) Root galls on noni roots caused by M. javanica in São Roque do Canaã county, ES; (b) Debilitated noni plants with a large population of Meloidogyne javanica associated with their roots. Source: Antônio Fernando de Souza.
Figure 2. Polyacrylamide gel showing the esterase phenotypes of females of Meloidogyne javanica extract from seven commercial areas of noni in the State of Espírito Santo, Brazil. Lanes left to right: Samples from: Colatina (1) and São Roque do Canaã (2-7), ES, Brazil. (8) M. javanica was used as the standard.
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Nematodes from the Meloidogyne genus cause considerable damage in many crops, but lack of knowledge among producers may lead them to attribute this damage to other factors, such as abiotic stresses (extreme temperature, nutritional deficiencies, etc.)[12].
As observed in Table 1, most of the sampled areas have been planted for 2 to 4 years. However, area 3 was implanted 10 years ago. Although no systematic study has been carried out to quantify damage in the area, this long coexistence of nematode and plant has led to one of the largest populations of M. javanica seen among the sampled areas (32862.5), and this may have caused a reduction in the size of fruit and thus of yield, according to the producer.
When a given crop is cultivated in an area with phytonematodes present, an increase in the population of these pathogens over time can be predicted[13]. This occurs because these pathogens multiply on a logarithmic scale, and thus, according to the aforementioned authors, a female produces, on average, 500 eggs. Taking into account the survival of only 5% of the individuals that are going to complete their cycle, mean populations are reached of 25, 625, 15,625 and 390,625 adults in one to four generations, respectively. This justifies the observations in the present research, in which the older plants (4 and 10 years old), which have coexisted for longer with the nematode, were those that presented the greatest nematode populations (Table 1).
Parasitism of plants by nematodes is characterized by the creation of permanent feeding sites in the root tissues, constituted by giant cells on the cortex, endodermis, pericycle and parenchyma[14]. These feeding sites become drains for photoassimilates and thus jeopardize plant growth and development[15].
Furthermore, the mechanical damage provoked by nematodes that penetrate and move inside plant tissues leads to the blockage of vascular tissues in the feeding sites. This limits the translocation of water and nutrients, reducing plant growth and crop yield[16]. All these physiological and mechanical damages lead to decreased growth of the plants[17], which may explain the decline seen in noni plants parasitized by M. javanica.
It is important to emphasize the importance of phytonematode population surveys in commercially cultivated crops[18, 19]. Greater knowledge of phytonematodes associated with the noni crop is also important in the management of these pathogens. Thus, with the knowledge acquired in this study, affirming that the species of nematode associated with areas of noni is M. javanica, more effective management measures can be implemented.
In order to manage phytonematodes, the most efficient and economical method is the use of resistant cultivars[20], because these make it possible to maintain nematode populations below the level that causes economic losses[19]. As RKNs present a high level of host specialization, the most desirable management of Meloidogyne spp. is the use of genetic resistance[21]. The information generated in the present study is also important because, should the producer wish to remove the noni crop from the area and plant a new one, a crop or cultivar resistant to M. javanica could be chosen.
CONCLUSIONSThe root-knot nematode species associated with the noni culture crop in evaluated areas in the
municipalities of Colatina and São Roque do Canaã, Espírito Santo State, Brazil, is M. javanica. This is the first report of this pathosystem in the state.
Table 2. Number of second-stage juveniles (J2) of Meloidogyne javanica obtained in soil and root samples from noni in commercially cultivated areas in Espírito Santo state.
Area Eggs + J2/ g root J2/100 cm3 soil Total Population
1 561 975 1536
2 689 870 1559
3 1615 562.5 2177
4 1140 960 2100
5 309 1020 1329
6 170 540 710
7 1887 1044 2931
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REFERENCES1. Silva LR, Medeiros PVQ, Leite GA. 2009. Caracterização física do fruto de noni (Morinda citrifolia L.). Horticultura
Brasileira, 27: 267-271.
2. Silva LR, Pontes CA, Sousa JA. 2013. Qualidade de frutos de noni (Morinda citrifolia L.) cultivados em Trairi-CE. Revista Cubana de Plantas Medicinais, 18: 100-108.
3. Nelson SC. 2003. Morinda citrifolia L. Rubiaceae (Rubioideae) coffee family. Permanent Agriculture Resources, Holualoa, 13 pp.
4. Nelson SC, Elevitch CR. 2006. Noni: the complete guide for consumers and growers. Permanent Agriculture Resources, Holualoa, 104 pp.
5. Nelson SC. 2005. Noni root-knot, a destructive disease of Morinda citrifolia in Hawaii. Plant Disease, 27: 1-4.
6. Kavitha PG, Jonathan EI, Nakkeeran S. 2011. Life cycle, histopathology and yield loss caused by root knot nematode, Meloidogyne incognita on noni. Madras Agriculture Journal, 98: 386-389.
7. Fu MY, Wang HF, Chen MC. 2013. First report of the root-knot nematode Meloidogyne arenaria infecting noni in China. Disease Notes, 97: 1518.
8. Souza VHM, Bonfim MF Jr, Antedomenico SS, Inomoto MM. 2015. First report of Meloidogyne javanica infesting noni (Morinda citrifolia) in Brazil. New Disease Reports, 31: 12. http://dx.doi.org/10.5197/j.2044-0588.2015.031.012.
9. Coolen WA, D’Herde CJ. 1972. A method for the quantitative extraction of nematodes from plant tissue. State Agricultural Research Centre, Ghent, 77 pp.
10. Jenkins WR. 1964. A rapid centrifugal-flotation technique for separating nematodes from soil. Plant Disease Reporter, 48: 692.
11. Carneiro RMDG, Almeida MRA. 2001. Técnica de eletroforese usada no estudo de enzimas dos nematoides de galhas para identificação de espécies. Nematologia Brasileira, 25: 555-560.
12. Timmer LW, Garnsey SM, Broadbent P. 2003. Diseases of citrus. In: Ploetz RC (ed.). Diseases of tropical fruit crops. CAB International, Wallingford, p. 197-226.
13. Taylor AL, Sasser JN. 1978. Biology, identification and control of root-knot nematodes (Meloidogyne spp.). International Meloidogyne Project, North Caroline, 111 pp.
14. Freitas LG, Oliveira RDL, Ferraz S. 2006. Introdução à nematologia. 3rd ed. UFV, Viçosa, 83 pp.
15. Vovlas N, Hava FR, Díaz RMJ, Castillo P. 2005. Differences in feeding sites induced by root-knot nematodes, Meloidogyne spp., in chickpea. Phytopathology, 95: 368-375. PMid:18943038. http://dx.doi.org/10.1094/PHYTO-95-0368.
16. Hussey RS, Williamson VM. 1997. Physiological and molecular aspects of nematode parasitism. In: Barker KR, Pederson GA, Windham GL (eds.). Plant and Nematode Interactions. American Society of Agronomy, Wisconsin, p. 87-108.
17. Calzavara SA, Santos JM, Favoreto L, Barbosa JC. 2008. Desenvolvimento de plantas jovens de citros infectadas por Pratylenchus jaehni (Nematoda: Pratylenchidae) em microparcelas. Nematologia Brasileira, 32: 212-219.
18. Zem AC, Reinhardt DHRC. 1978. Nematoides associados à cultura do abacaxi no estado da Bahia. Resumos da Sociedade Brasileira de Nematologia, 3: 17-20.
19. Dias-Arieira CR, Furlanetto C, Santana SM, Barizão DAO, Ribeiro RCF, Formentini HM. 2010. Fitonematoides associados a frutíferas na região noroeste do Paraná, Brasil. Revista Brasileira de Fruticultura, 32: 1064-1071. http://dx.doi.org/10.1590/S0100-29452010005000119.
20. Kanayama FS, Sera GH, Sera T, Mata JS, Ruas PM, Ito DS. 2009. Progênies de Coffea arabica cv IPR 100 com resistência ao nematoide Meloidogyne incognita raça 1. Ciência e Agrotecnologia, 33: 1321-1326. http://dx.doi.org/10.1590/S1413-70542009000500018.
21. Roberts PA. 2002. Concepts and consequences of resistance. In: Starr JL, Cook R, Bridge J (eds.). Plant resistance to parasitic nematodes. CAB International, Wallingford, p. 23-41.
