Root-knot nematode

In our recent study, BABA has been tested to manage Meloidogyne incognita under stress conditions due to fly ash. The reduction in the growth of pathogen under abiotic stress is being intensified by DL-β-amino butyric acid (BABA). The combination of abiotic and biotic stress can have a positive effect on the yield of plants by reducing the sensitivity to biotic tension and limiting the crop yield and more priority has been given on the surface of the research table now a days. Therefore this study was carried out observe the effect in combination of Fly ash and BABA in resistance to Root knot nematodes. Results indicate that 30% fly ash in combination with BABA (125 μg/ml) undoubtedly reduced the gall Index by 50% when compared with the control. The interesting thing is that the lower dose of BABA when combined with the abiotic stress was similar to the high dose of BABA efficacy (250 μg / ml).

Several root-knot nematode (Meloidogyne spp.) resistance genes have been discovered in different pepper (Capsium annuum L.) lines; however, none of them has yet been cloned. In this study, a candidate root-knot nematode resistance gene (designated as CaMi) was isolated from the resistant pepper line PR 205 by degenerate PCR amplification combined with the RACE technique. Expression profiling analysis revealed that this gene was highly expressed in roots, leaves, and flowers and expressed at a lower level in stems and was not detectable in fruits. To verify the function of CaMi, a sense vector containing the genomic DNA spanning the full coding region of CaMi was constructed and transferred into root-knot nematode susceptible tomato plants. Sixteen transgenic plants carrying one to five copies of T-DNA inserts were generated from two nematode susceptible tomato cultivars. RT-PCR analysis revealed that the expression levels of CaMi gene varied in different transgenic plants. Nematode assays showed that the resistance to root-knot nematodes was significantly improved in some transgenic lines compared to untransformed susceptible plants, and that the resistance was inheritable. Ultrastructure analysis showed that nematodes led to the formation of galls or root knots in the susceptible lines while in the resistant transgenic plants, the CaMi gene triggered a hypersensitive response (HR) as well as many necrotic cells around nematodes.

Rice (Oryza sativa) is one of the important staple crops for most of the countries in the world. Plant parasitic nematodes(PPN) are an important pest of rice. There are many diseases caused by nematodes in rice and among them, Meloidogyne graminicola causes wide yield loss. Growing concerns about environment and health have led to less use of pesticides and opt for more environmentally safe, ecologically sound and economically feasible alternatives. The control measures applied in the rice field for controlling RKN are mostly chemical, biological, cultural methods and using of resistant varieties. Biological control agents (BCA) like nematophagous fungi and nematophagous bacteria can be an alternative to chemical pesticides. The increase in production of the crop or controlling of the root-knot nematodes should not only be focused if we are looking at the sustainable rice production. This review addresses the integrated approach where all the control measures are combined without affecting the environment, human and soil health. This review focuses on the current scenario of rice root-knot nematodes and the control measures applied to overcome it. Importantly it discusses the importance of the integrated approach used for controlling M. graminicola in rice and their management strategies.

Potato is one of the most important food crops with a capacity to abate hunger among farmers in the region. However, its productivity has stagnated and remained low due to poor agronomic practices applied by smallholder farmers. To avert this situation, dissemination through training of already existing better technologies and practices should be prioritized. A lot of research has been done with better recommendations-use of disease-free tuber seeds from high yielding and tolerant varieties, adequate application of balanced nutrients, timely scouting and integrated management of pests and diseases and good harvesting practices are available for immediate adoption. The adoption and dissemination could be facilitated by currently existing policies that promote cross-border movement and diffusion of research technologies and new varieties.

Sulfur nanoparticles (S-NPs) were prepared using rosemary (Rosmarinus officinalis) leaves aqueous extract and sodium thiosulfate pentahydrate (Na2S2O3.5H2O) at room temperature. The S-NPs were characterized by UV–visible spectrophotometer, Fourier transform infrared (FT-IR), Scanning electron microscopy (SEM), Transmission electron microscopy (TEM), and X-ray diffraction (XRD) techniques. The sulfur nanoparticles are crystalline in nature with average size of 40 nm. The morphology of S-NPs could be controlled by tuning the amount of rosemary leaves aqueous extract and sulfur ions. The cytotoxic effects of the S-NPs on hatching of second stage root-knot and mortality of second stage of root-knot nematode (Meloidogyne javanica) were tested. These results confirmed that the S-NPs synthesized using rosemary leaves aqueous extract and could possibility be used as nematicidal to manage M. javanica infestation.

El objetivo del presente estudio fue realizar una prospección de nematodos fitoparásitos asociados al cultivo de cebolla en el valle de Asunción Mita y relacionarlos con la presencia de Fusarium oxysporum. Se realizaron muestreos de suelo en diferentes puntos del valle de Asunción Mita en parcelas con cebolla. En cada punto se tomaron 10 submuestras para obtener una muestra compuesta de aproximadamente 1-2 Kg. Se trasladaron las muestras al laboratorio de patología vegetal en el Campus Central de la Universidad Rafael Landivar y se utilizó el método de tamizado y centrifugado con flotación en azúcar para la extracción de los nematodos. La identificación de géneros de los especímenes extraídos se realizó con base a la clave de identificación para hembras de Mai y Mullin (1996). Se cuantificó la incidencia de F. oxysporum en parcelas matrices de un metro cuadrado colocando un marco de madera en tablones con plantas sintomáticas y se contó la cantidad de plantas afectadas entre en total de plantas que cabían dentro del marco. Los resultados indican la presencia de diez géneros de nematodos: Aphelenchoides, Helicotylenchus, Meloidogyne, Paratrichodorus, Pratylenchus, Scutellonema, Hoplolaimus, Criconemoides, Tylenchorynchus y Tylenchus. En promedio se encontraron con mayor presencia el género Helicotylenchus (26.5 nematodos/100cc de suelo) y menor cantidad los géneros Meloidogyne y Paratrichodorus (1 nematodo/100cc de suelo). Se pudo observar una incidencia de F. oxysporum distribuido en parcelas del valle que va de 10%-50%. Los resultados indicaron que no existe  relación de la incidencia de F. oxysporum con la cantidad total de nematodos, lo cual se concluye que los nematodos fitoparásitos en el valle de Asunción Mita, no son factores inductivos de esta enfermedad.

Nematoda puru akar (NPA) Meloidogyne spp. merupakan salah satu patogen penting pada berbagai tanaman hortikultura dan beberapa tanaman pangan di Indonesia. Infeksi NPA mampu menurunkan kuantitas dan kualitas panen, bahkan menyebabkan gagal panen apabila terjadi sinergisme dengan patogen lain. Penggunaan pestisida kimia sintetis untuk mengendalikan Meloidogyne spp. dan patogen lain di kalangan petani sering melebihi batas pemakaian normal. Selain menyebabkan kerusakan dan pencemaran lingkungan, penggunaan pestisida kimia sintetis dapat menyebabkan gangguan kesehatan pada petani, meninggalkan residu kimia yang berbahaya bagi konsumen, dan menurunkan jumlah mikroba dan mikro fauna yang berperan penting dalam pertanian berkelanjutan. Masalah tersebut dapat ditekan tingkat kejadiannya dengan mengurangi penggunaan pestisida kimia sintetis. Terdapat banyak pilihan cara untuk mengendalikan NPA tanpa menggunakan pestisida kimia sintetis, yaitu dengan pola tanam polikultur, memanfaatkan tanaman antagonis, teknik biofumigan, penggunaan ekstrak nabati (pestisida nabati), penggenangan sawah, aplikasi agens antagonis, dan aplikasi metabolit sekunder dari mikroba. Cara-cara tersebut diketahui efektif menekan populasi NPA pada berbagai skala percobaan, dan tidak menimbulkan masalah lingkungan. Beberapa teknik aplikasi seperti pola tanam polikultur, dan aplikasi agens antagonis diketahui tidak hanya menekan populasi NPA dan mengurangi kerusakan akibat infeksi NPA, namun juga mampu meningkatkan hasil panen. Teknik-teknik pengendalian patogen yang ramah lingkungan perlu dilakukan untuk mewujudkan swasembada pangan melalui pertanian berkelanjutan.

Kata kunci: Meloidogyne spp., nematoda puru akar, pengendalian

Six tomato cultivars Moneymaker, Beefsteak, Roma, Summertaste, Mini Roma and Smallfry were tested for their susceptibility to root- knot nematodes at inoculum levels of 200, 400, 600 Juveniles (J2) per pot. All were found to be susceptible to varying degrees as egg masses were present in all with Moneymaker and Roma being the most susceptible and Mini Roma, the least susceptible. The inoculum levels had a significant effect (p<0.05) on the number of galls and plant weights. The gall numbers and plant weights was negatively correlated, with the highest gall numbers and lowest plant weights recorded at the highest inoculum level in all cultivars except in Mini Roma in which there was little variation in gall numbers and plant weights.

Okra (Abelmoschus esculuntus (L.) Moench) is a popular vegetable in Ghana but its production is limited by nematode infestation of soils. Pot experiments were carried out in a plant house at the Nyankpala campus of the University for Development Studies (UDS), Tamale to assess the effect of aqueous sesame seed extract on rootknot nematodes (Meloidogyne spp.) of okra. The experiment was laid out in a completely randomized design with each of the four treatments replicated four times. Treatments consisted of three levels of sesame seed extract (10,20 and 30 g/50ml) per pot and a control (0 g/50ml). All pots were inoculated with 1000 root-knot nematode eggs a week before the application of the treatments. Data collected included plant height, number of leaves, stem girth, fruit weight, fresh root weight, number of fruits, nematode eggs per 50 g of fresh soil and root galling index. The results showed that aqueous extract of S. indicum at 30 g/50 ml (w/v) suppressed root-knot nematodes better than the control. Similarly, okra plants treated with S. indicum had the lowest infection index (root gall). There were significant differences (P<0.05) among the treatment means for number of fruits and fruit weight of okra between aqueous sesame seed extract at 30 g/50 ml and the control. Yield of okra can be enhanced and nematode population reduced through the application of sesame seed extract preferably at 30 g/50ml

Aims: To evaluate the nematicidal potential of wild spinach powder in combination with fresh chopped leaves of different plants viz., Indian mallow, Mexican poppy, Ivy gourd, Trailing eclipta, Wild eggplant and Black pigweed against Meloidogyne incognita on plant growth characters of tomato cv. K-21. Place and Duration of Study: A glasshouse pot experiment was carried out in the Department of Botany, Aligarh Muslim University, Aligarh. Methodology: A mixture of soil and organic manure was prepared in the ratio 3:1. The pots were treated with fresh chopped leaves of different plants viz., Indian mallow, Mexican poppy, Ivy gourd, Trailing eclipta, Wild eggplant and Black pig weed applied 50 g of fresh chopped leaves of plants were applied combined with seed powder 10 g of seed powder of Black nightshade ". Results: Combined application of wild spinach powder along with the fresh chopped leaves of all the plants suppressed pathogenic effect of nematode and thereby resulted in significant reduction Original Research Article Asif et al.; AJOB, 1(1): xxx-xxx, 2016; Article no.AJOB.30739 2 in Meloidogyne incognita infestation and population density of Meloidogyne incognita in soil. The highest reduction in Meloidogyne incognita infestation was reported in plants employed with 10 g of wild spinach powder combined with 50 g of Mexican poppy leaves. Plants applied 10 g of wild spinach powder combined with 50 g of Mexican poppy leaves were the best followed by 50 g of Trailing eclipta, 50 g of Wild eggplant, 50 g of Black pigweed, 50 g of Indian mallow, 50 g of Ivy gourd in the descending order. However the lowest reduction was recorded with the application 10 g of wild spinach powder plus 50 g of fresh chopped Ivy gourd. Organic additives of wild spinach powder along with the fresh chopped leaves would work for sustainable management by increasing the nutrient status of the soil which further enhances the plant growth. Conclusion: The application of Mexican poppy, Trailing eclipta and Wild eggplant in combination with wild spinach powder are quite efficient alternatives of chemical nematicides for the Meloidogyne incognita management and yield enhancement. Although the utilization of chopped leaves of Indian mallow and Ivy gourd along with wild spinach powder is not potentially active replacement of synthetic nematicides however further characterization is needed.

The southern root-knot nematode (RKN) (Meloidogyne incognita (Kofoid & White)) is a serious pest of cotton (Gossypium hirsutum L.) with detrimental effects being most pronounced on sandy soils that are also infested with the Fusarium wilt pathogen. Varietal resistance is an effective method of managing the RKN/Fu- sarium wilt complex. In 1970, a high level of RKN resistance was developed in the germplasm line Auburn 623 RNR, but no commercial cultivar has been developed with this near-immunity level of resistance. The objective of this study was to eval- uate the mode of inheritance of RKN resistance in M-315 RNR (M-315), a germplasm line with the Auburn 623 RNR source of resistance, and in M78-RNR, a day-neutral version of the race stock line T78. These lines were crossed with M8, an RKN-susceptible cotton line, and with each other. The parental, F1, F2, and backcross generations of these crosses were evaluated in the greenhouse for RKN reproduction 40 d after planting in a Wickham...

The common soil inhabiting nematophagous fungus Paecilomyces lilacinus (Thom) Samson and the nematode trapping fungus Monacrosporium lysipagum (Drechsler) Subram were assayed for their ability to reduce the populations of three economically important plant-parasitic nematodes in pot trials. The fungi were tested individually and in combination against the root-knot nematode Meloidogyne javanica (Treub) Chitwood, cereal cyst nematode Heterodera avenae Wollenweber, or burrowing nematode Radopholus similis (Cobb) Thorne on tomato, barley and tissue cultured banana plants, respectively. In all cases, nematode populations were controlled substantially by both individual and combined applications of the fungi. Combined application of P. lilacinus and M. lysipagum reduced 62% of galls and 94% of M.␣javanica juveniles on tomato when compared to the experiment with no fungi added. Sixty five percent of H. avenae cysts were reduced on barley by combined application of fungi. Control of R. similis on banana, both in the roots and in the soil, was greatest when M. lysipagum was applied alone (86%) or in combination with P. lilacinus (96%), using a strategy where the fungi were inoculated twice in 18 weeks growth period. Overall, combined application of P. lilacinus and M. lysipagum was the most effective treatment in controlling nematode populations, although in some cases M. lysipagum alone was as effective as the combined application of fungi, particularly against M. javanica.

Weeds can act as reservoir hosts of a range of pests and diseases. Information and knowledge on the host status of weeds to common pests and diseases can be used to develop integrated weed and pest management strategies. As part of a survey on the distribution and diversity of root-knot nematodes on crops in Fiji, the root-knot nematode host status of weeds was also studied. Weeds growing in root-knot nematode infested farms (n  =  189) and bioassay pot soil samples (n  =  277) were identified, and their host status was determined on the basis of a root gall and egg-mass index scale from 0 to 5. A total of 45 weed species were recorded as potential weed hosts of root-knot nematodes with a gall index from 1 to 5. Using the weed and tomato bioassay method, a total of 11 nonhost weed species were recorded with a gall index of 0, relative to infected tomato growing in pot soil samples. Common weeds infected by root-knot nematodes on farms and in bioassay pot soil included slender amaranth, old world diamond-flower, tropic ageratum, sicklepod, mimbra, balsamapple, purple bushbean, little ironweed, ivy gourd, and cutleaf groundcherry. The presence of egg masses on the weed hosts indicated their ability to sustain root-knot nematode populations and, thus, their potential to act as reservoir hosts.

Root-knot nematodes, Meloidogyne incognita in Guatemala and Meloidogyne sp. in El Salvador frequently cause very serious damage to Coffea arabica. Hypocotyledon grafting on C. canephoravar. Robusta is practiced on a very wide scale to control these pests. However, rootstock seeds come from non selected trees which provide 30–40%resistance. In this article, we examine the possibility of improving resistance to M. incognita and Meloidogyne sp. Hybrids were created using two North Carolina II factorial mating designs and tested under controlled conditions for resistance to isolates of the two nematodes. In the trial with Meloidogyne sp. the number of nematodes per plant was counted, and in the trial withM. incognita a root damage index was established. Vegetative measurements (height, weight of aerial parts and roots) were taken in both trials. The parents were classed according to their cross value and genetic variance was estimated. In the factorial trial conducted with the Meloidogynesp. isolate from El Salvador, parents T3561 and T3751transmitted high resistance levels of 56 and 54%,respectively, to their progenies, as opposed to 9% for the other parents. The cross between those two parents achieved 78% resistant plants. In the trial with the M. incognita isolate from Guatemala, similar results were found. The same two parents transmitted resistance to 64% of their progenies, as opposed to 36% for the other parents. Classification of the parents did not differ from one trial to the other. The existence of a complex nematode resistance locus in the C. canephora species seems highly likely. The results show that it is possible to select rootstock varieties that are more resistant to the main Meloidogyne nematodes in Guatemala and El Salvador. Given the average heritability values (0.28–0.30) and the possibility of applying strong selection intensity, the genetic progress expected in the next selection cycle should be substantial.

Bacillus species are well known rhizobacteria for their potential to improve plant growth and control of plant pathogens. Bacillus species were isolated from rhizosphere of different crop plants in lower Sindh. Secondary metabolites of Bacillus cereus (KUB-15), B. coagulans (KUB-20) and B. cereus (KUB-27) were extracted in ethyl acetate and hexane. Two concentrations (500 and 1000 ppm) of these extracts were applied to Okra (Abelmoschus esculentus [L.] Moench) seeds for the assessment of a) plant growth promoting ability b) root-knot nematode parasitism and c) infection of root-infecting fungi. Both extracts at 1000 ppm concentration showed significantly higher plant height and weight compared to lower concentration (500ppm). Root-knot nematode parasitism was measured in term of number of galls, egg masses and eggs/egg mass. Lower concentrations of the extracts showed greater parasitism of nematodes compared to higher concentration of both the solvents. Least root-knot nematode parasitism was observed in plants treated with ethyl acetate extract of KUB-20 at 1000 ppm. Colonization of three root-infecting fungi namely, Macrophomina phaseolina, Rhizoctonia solani and Fusarium species was recorded. Lowest infection of M. phaseolina (8.86%) and R. solani (17.71%) was observed with ethyl acetate extracts of KUB-20 and KUB-27, respectively. However, colonization of Fusarium species was greatly reduced by both ethyl acetate and hexane extracts of KUB-20 at 1000 ppm.

Seed extracts of Castor (Ricinus communis L.) and Amaltas (Cassia fistula L.) were screened for their nematicidal activity against Meloidogyne incognita (Kofoid and White) Chitwood. Aqueous extract of seeds at the concentration of 100, 50, 25 and 20 percent showed 100 percent larval mortality whereas delaying and reduction in egg hatching was also observed. Economic importance of non-edible oil seeds of Castor (Ricinus communis L.), Amaltas (Cassia fistula L.) is due to the presence of variety of secondary metabolites that are useful in pharmaceutical and chemical industry. Present study reveals the presence of terpenoids, steroids, tannins, proteins, coumarins, saponins, phenols, carbohydrates and flavonoidsin methanolic seed extract of Castor and Amaltas. Phlobatannins was appear to be absent in these seeds. Amaltas had highest concentrations of these bioactive compounds followed by Castor.