Javanica Populations Research Articles

Application of herbicides in green cover crops to reduce Meloidogyne javanica inoculum in soybean plants

Nematodes are among the main plant parasites affecting Brazilian agriculture. Management practices involving the use of antagonistic or non-host plants are crucial for combating Meloidogyne javanica populations in the country. However, there is still limited information on the effects of herbicides on nematode populations. The aim of this research was to evaluate the impact of herbicides applied to crops on M. javanica populations in soybean and to examine the direct effect of herbicide products on the hatching of nematode juveniles. We conducted greenhouse and in vitro experiments. In the greenhouse experiment, soybean plants were grown in pots with sterile substrate, and a soybean seed was inoculated with 2000 nematodes per plant. The plants grew for 60 d, after which they were cut, and the following cover crops were planted: Crotalaria spectabilis, pigeon pea (Cajanus cajan), Stylosanthes, and buckwheat (Fagopyrum esculentum) for 60 d. These cover crops were desiccated with one of the following three herbicides: fomesafen, chlorimuron, or bentazone. Subsequently, soybeans were replanted and cultivated for additional 60 d. In vitro assays were used to determine the hatching percentage of M. javanica eggs exposed to herbicides. Both tests were repeated at different times of the year (Trials 1 and 2). Meloidogyne javanica reproduction was higher on soybean crops grown when buckwheat was a cover crop. Herbicide application reduced total nematode numbers in soybean grown in succession to buckwheat compared with the untreated control. The vegetative development of soybean crops was negatively influenced by herbicide treatment of cover crops, especially with the use of chlorimuron. Bentazone and fomesafen did not affect nematode hatching in vitro.

First Report of Meloidogyne javanica Infecting Strawberry (Fragaria × ananassa) in the United States.

Strawberry (Fragaria × ananassa) is native to temperate regions. However, it has been produced in tropical areas, as a seasonal crop including in Florida, USA during the winter months. In March 2022, root galls resembling those induced by root-knot nematodes (Meloidogyne spp.) were observed in declining strawberry plants 'WinterstarTM FL 05-107' growing in an organic-certified research site in Hillsborough County, Florida, USA. To our knowledge, M. hapla is the only root-knot species reported to infect strawberry in Florida. Preliminary molecular analyses, including newly synthesized DNA sequences (TW81/AB28 = OQ469833 - OQ469836; D2A/D3B= OQ473043 - OQ473047) using extracted nematode females from the strawberry roots, initially identified the RKN as M. javanica. Nematode species confirmation was further performed using the morphology of the female perineal patterns and isozyme analysis, mainly esterase (EST) and malate dehydrogenase (MDH), DNA sequencing, (NAD5-F/NAD5-R) and the SCAR primer set (Fjav/Rjav), species-specific for M. javanica. Isozyme analyses, EST= J3, which is specific for M. javanica and MDH=N1, as well as the morphology of female perineal patterns, agreed with data previously reported for M. javanica. A pathogenicity test on strawberry 'WinterstarTM FL 05-107' transplants was performed using 10,000 eggs of the original M. javanica population, which induced galls on strawberry plants (Gall index, GI = 4.1) with egg masses clearly visible outside of the roots, producing an average of 1,344 eggs/gram of fresh root and 9,201 ± 4,206 eggs/root system. No galls or egg masses were observed on non-inoculated plants. Tomato 'HM 1823' was used as a control for the viability of the inoculum and showed numerous galls and egg masses (GI=5.0;). The newly obtained DNA sequences using NAD5-F/NAD5-R (OQ474970 - OQ474972) were compared with other sequences available in the GenBank and were shown to be 100% identical to five M. javanica populations from Polk County, Florida, USA (OM418745 - OM418749) and the complete mitochondrion genome of M. javanica (NC026556). To our knowledge, this is the first report of M. javanica infecting strawberry in the United States.

Biochemical and molecular identification of root-knot nematodes in greenhouse vegetable areas of Eastern Mediterranean Region (Turkey)

Root-knot nematode surveys were conducted during the growing seasons of 2017 and 2018 to cover the greenhouse vegetable areas in Mersin, Hatay and Adana Provinces in the Eastern Mediterranean Region (Turkey). A total of 46 root-knot nematode populations were characterized using biochemical and molecular diagnostic techniques. DNA extraction was done from second-stage juvenile and in molecular tests using SCAR primers, Meloidogyne arenaria (Neal, 1889) Chitwood, 1949, Meloidogyne javanica (Treub) Chitwood, 1949, Meloidogyne incognita (Kofoid & White, 1919) Chitwood, 1949, Meloidogyne hapla Chitwood, 1949 and Meloidogyne ethiopica Whitehead, 1968 (Tylenchida: Meloidogynidae) species were screened. Samples obtained from thirty-nine regions were identified as M. incognita (85%) and seven as M. javanica (15%). In addition, young females obtained from all regions were biochemically analyzed using the polyacrylamide gel electrophoresis diagnostic method. The esterase enzyme profile was examined to identify the M. incognita , M. javanica and M. ethiopica groups. Esterase phenotype I1 band was observed in 62% of M. incognita populations and esterase phenotype I2 band was observed in 39%. Esterase phenotype J3 band was detected in all M. javanica populations. M. javanica and M. incognita were verified and also supported by molecular and biochemical methods in the Eastern Mediterranean Region.

Variant Meloidogyne javanica populations from Brazil could impact the breeding programs and the management in soybean fields

Variant Meloidogyne javanica populations from Brazil could impact the breeding programs and the management in soybean fields

Macrotyloma axillare ‘Java’ and Crotalaria spp. combined with biocontrol agents for the management of Meloidogyne javanica in soybean

AbstractThis study aimed to investigate the effects of crop rotation with Macrotyloma axillare ‘Java’, Crotalaria spectabilis and Crotalaria ochroleuca combined with green manure application or biological treatment, on the control of Meloidogyne javanica in soybean. An initial greenhouse study was conducted in a 4 × 2 factorial design, with four rotation crops (M. axillare ‘Java’, C. spectabilis, C. ochroleuca and soybean) in the presence and absence of green manure. A second greenhouse study was carried out using a 4 × 5 factorial design, with four rotation crops and five biocontrol treatments (Pochonia chlamydosporia, Purpureocillium lilacinum + Trichoderma harzianum, Bacillus methylotrophicus, Bacillus subtilis + Bacillus licheniformis and untreated control). Both experiments consisted of two independent trials (Trials 1 and 2) conducted at different times of the year. The experimental field soil was infested by growing soybean infected with M. javanica for 50 days prior to the assays. Then, seeds of rotation crops were sown and biocontrols applied. Rotation crops were removed 70 days after sowing, and soybean seeds were sown immediately afterwards. Total nematodes, nematode per gram of root and soil biological activity were assessed 60 days after soybean sowing. In the first study, all rotation systems and green manure treatments reduced M. javanica population. In the second study, all biological treatments were effective, except B. methylotrophicus and M. axillare ‘Java’ combined with P. chlamydosporia in Trial 1 and C. spectabilis combined with P. lilacinum +T. harzianum in Trial 2. Macrotyloma axillare ‘Java’ combined with B. methylotrophicus and C. spectabilis combined with B. subtilis +B. licheniformis resulted in higher soil metabolic activity. The association of biological control agents with crop rotation generally did not present additive effects in the reduction in M. javanica populations, except for one combination of M. axillare ‘Java’ with B. subtilis +B. lichneniformis.

Habitat characteristics and population of leptophryne javanica in Curug Cisurian, Kopi Bojong, and Ciinjuk in Gunung Ciremai National Park

Mount Ciremai National Park (TNGC) has a high diversity of flora and fauna, one of which is Leptophryne javanica. Amphibians of the Ordo Anura are declared as new species. Habitat disturbance and destruction by natural and human activities is one of the main threats to the extinction of this species. The purpose of this study was to determine the habitat characteristics and populations of the Leptophryne javanica species in TNGC. The method used in this study is the analysis of vegetation as well as data collection on environmental physical conditions for habitats and capture mark re-capture for population data. Correlation analysis used is the rank sperman. Based on the results of research on vegetation at the tree and pole level that dominates is Nangsi (Villebrun rubescens ) while at the lower plant and seedling level is Balakacida (Barreria laevis ). Physical environmental parameters that significantly affect the species of Leptophryne javanica are water temperature with a value (-min) -0.953, this shows that the lower the water temperature at a certain level, the more the number of Leptophryne javanica populations will be found

Biocontrol potential of nematophagous fungi against Meloidogyne spp. infecting tomato

Root-knot nematodes are the most economically damaging group of plant parasitic nematodes. Intensive agriculture on sandy soil of Moroccan agroecosystems results in a prevalence and wide distribution of Meloidogyne spp., limiting both conventional and organic fruit and vegetable production. The aim of this study is to assess the nematicidal potential of twelve local isolates of nematophagous fungi in organic tomato production in laboratory and greenhouse conditions. Fungal isolates were of seven genera: Paecilomyces, Purpureocillium, Trichoderma, Fusarium, Talaromyces, Arthrobotrys, Dreschslerella, and Monacrosporium. In vitro assays screened the isolates for their ability to immobilize Meloidogyne javanica juveniles using 96-well tissue culture plates at a concentration of 106 spores.ml−1. The same isolates were tested for their potential to reduce M. javanica populations and galling on tomato roots in pot experiments with infested soil, applied upon transplantation at 107 spores.ml−1. Average mortality rate of second-stage juveniles of Meloidogyne spp. in vitro ranged from 11 to 42%, with a maximal range of 64 to 73% mortality. The highest rates of mortality were recorded after 72 h using Purpureocillium lilacinum and Arthrobotrys oligospora. In pot experimentation, the reproduction rate of root-knot nematodes ranged from 176 to 5920% with the gall index varying from 2.7 to 4.9 in treated pots. This study identified Paecilomyces and Arthrobotrys direct nematicidal effect against Meloidogyne spp., in laboratory conditions. To achieve successful control, further studies should be conducted to identify the optimal range of environmental factor practices which lead to the enhancement of biocontrol activity of these NF in the field.

Identification and characterization of Javanese root-knot nematode (Meloidogyne javanica) suppressive soils in Florida

In Florida, Javanese root-knot nematode (Meloidogyne javanica) is widely distributed and causes extensive damage to a number of economically important crops. Soil fumigants are commonly used to manage this soilborne pest; however, increasing societal concerns regarding the negative effects of these products on environmental and human health are driving a shift towards more sustainable management options. Of particular interest are naturally occurring nematode suppressive soils. Identifying farming practices and ecological factors that enable suppressive organisms to function and persist in soil will support the implementation of natural biological control. In this study, we evaluated suppressiveness to M. javanica in 12 soils from Florida. Using next-generation sequencing technology, we characterized the bacterial and fungal communities in these soils to further understand how those communities may contribute to nematode suppressive soils. In spring 2018, soil was collected from multiple geographic regions, production systems, and management practices within the state of Florida. In a soil-based suppressiveness assay, soil collected from 7 out of 12 of the sites reduced the recovery of inoculated J2-stage M. javanica relative to that of soil that had been steam-pasteurized. In a plant-based suppressiveness assay, all soils reduced root galling on cucumber by M. javanica relative to that of their steam-pasteurized counterparts. Contrary to other studies on pathogen suppressive soils, enhanced soil bacterial and fungal diversity was not associated with suppressiveness to M. javanica. Differences in soil fungal community composition was a stronger driver of suppressiveness than bacterial community composition, with the fungal orders Xylariales, Mortierellales, and Agaricales showing positive correlation with nematode suppressiveness across 64 % of the sites surveyed. Overall, Florida soils hold considerable potential to naturally regulate M. javanica populations. The use of soil management practices that promote the abundance and activity of suppressive microorganisms may reduce horticultural reliance on soil fumigants.

On-farm evaluations of non-fumigant nematicides on cucurbits

Non-fumigant nematicides were evaluated on cucurbits in two commercial farms in 2017 (Cucumis sativus and Cucumis melo) and three commercial farms in 2019 (Cucumis sativus, Cucurbita pepo and Citrullus lanatus). In 2017, non-fumigant nematicides (fluopyram, oxamyl, fluensulphone, and Majestene) were applied as stand-alone rescue treatments in a cucumber and cantaloupe field heavily infested respectively with Meloidogyne javanica and M. hapla. In 2019, non-fumigant nematicides (fluopyram, oxamyl, and Majestene) were applied both as stand-alone treatments, and as mixtures, in (i) a cucumber field (same as 2017) having a high population of M. javanica, (ii) a squash field previously planted with strawberry and having a high population of M. hapla, and (iii) a watermelon field, previously known to have a high population of sting nematode (Belonolaimus longicaudatus). In 2017, an additional tomato greenhouse study was conducted using the soil from both fields. Both fields in 2017 were re-planted following the rescue nematicide applications, and in the cantaloupe field the new crop established well enough to allow for commercial harvesting. All nematicide treatments in the 2017 cantaloupe field, except for oxamyl, were able to significantly reduce M. hapla root infection after 70 days. Oxamyl did reduce M. javanica root infection in the 2017 cucumber field after 30 days, but the re-planted crop did very poorly, and the field was abandoned after less than one month. In the greenhouse tomato trial, similar trends were observed with better efficacy of the nematicides against M. hapla as compared to M. javanica. In 2019, stand-alone applications of oxamyl and Majestene, and especially the fluopyram + Majestene cocktail significantly reduced the end-season soil population of M. javanica in the cucumber field. No significant effect of any of the products or cocktails was noted on B. longicaudatus in the watermelon field. In the squash field, oxamyl by itself tended to increase soil population of M. hapla, but the mixed application of fluopyram + oxamyl showed some suppression of M. hapla. In both 2017 and 2019 field trials, plant vigor and yield were not significantly affected by the application of any of the nematicides or cocktails. While the nematicides provided better suppression of M. hapla as compared to M. javanica in 2017, the opposite was noted in 2019. This was probably related to the more severe nematode pressure in 2017, especially in the M. javanica field. M. hapla populations tended to decrease during the spring season as soil temperatures increased, while the more tropical B. longicaudatus and especially M. javanica populations increased during the season. Results from this study indicate that although all three nematicides offer an opportunity for cucurbit growers in Florida to help manage nematodes during the cropping season, their efficacy in terms of reducing soil population density or root gall severity, will be dependent on the time of the year, the type of cucurbit that is grown, and the species of nematode present. Some evidence was shown of improved efficacy when nematicide cocktails were applied, but more research is needed to investigate this.

Association of Morphological, Ecological, and Genetic Diversity of Aerva javanica Populations Growing in the Eastern Desert of Egypt

Aerva javanica is one of Egypt’s most important traditional medicinal plants used as antidiarrheal and anthelmintic medicine and recently as an anticancer agent. In this study, variations among ten populations of Aerva javanica in different sites in the Eastern Desert of Egypt were analyzed based on morphological and ecological attributes and molecular variation expressed by Inter-Simple Sequence Repeat (ISSR) markers. Morphological diversity was higher for populations in the Wadi El-Markh and Bir Abbady regions than others. The polymorphism revealed by ten ISSR primers was 79.4% among populations. Distance trees created using the results obtained from soil variables, morphological characterizations, and molecular data showed that the highest similarity was 0.974 between Populations 8 and 9, while the lowest similarity was 0.715 between Population 1 and Population 3 regions. In conclusion, the obtained data are important to design a plan for sustainable conservation of Aerva javanica as an important medicinal plant having a wide interspecific genetic variability within various populations.

Occurrence of Meloidogyne javanica as a Pathogen of Cockscomb (Celosia cristata) in Brazil

Cockscomb (Celosia cristata L., family Amaranthaceae) is an ornamental plant species cultivated in pots or used as cut flowers in floral arrangements. In April 2018, cockscomb ‘Comum’ exhibiting many galls on the roots was detected and sampled from several areas (27°21′34″S, 53°23′37″W) of Frederico Westphalen county, Rio Grande do Sul State, Brazil. Identification of Meloidogyne sp. (Nematoda: Meloidogynidae) was carried out by observations of perineal patterns (n = 30) and esterase phenotypes (n = 30), morphological measurements of second-stage juveniles (J2) (n = 50), and amplification and sequencing of the ITS1-5.8S-ITS2 rRNA region (primer set: forward 5′-TTGATTACGTCCCTGCCCTTT-3′ and reverse 5′-TCCTCCGCTAAATGATATG-3′) and the D2 to D3 fragment of the 28S rRNA gene (primer set: forward 5′-ACAAGTACCGTGAGGGAAAGTTG-3′ and reverse 5′-TCGGAAGGAACCAGCTACTA-3′). In addition, cockscomb roots were processed to determine the number of J2 and eggs of Meloidogyne sp. Nematode population density observed in the sample was 2,100 J2 per gram of cockscomb roots. The J2 had the following morphometric characteristics: length (L) = 405.5 ± 61.0 (368.5 to 415.6) µm, a = 29.6 ± 2.5 (26.8 to 33.4), c = 8.00 ± 0.5 (6.0 to 9.6), stylet = 13.5 ± 0.5 (11.3 to 15.9) µm, dorsal esophageal gland orifice (DGO) = 3.20 ± 0.4 (2.9 to 3.9) µm, tail length = 55.5.5 ± 4.0 (54.1 to 59.5) µm, and hyaline tail terminus = 10.3 ± 0.8 (9.0 to 11.5) µm. Female perineal patterns included a low trapezoidal dorsal arch and smooth striae interrupted by a pair of incisions on both sides. These lateral ridges that divide the dorsal and ventral striae are unique to Meloidogyne javanica (Treub, 1885) Chitwood, 1949 (Rammah and Hirschmann 1990). The polymorphisms in the esterase bands observed during electrophoresis revealed the typical phenotype of J3 (Rm = 1.00,1.25, 1.40) M. javanica populations (Carneiro et al. 2000). Sequence homologies were determined by comparing sequences of polymerase chain reaction (PCR) amplicons of D2 to D3 of 28S and ITS1-5.8S-ITS2 rRNA region that were noted to be 516 bp (GenBank MK072827) and 554 bp (MK072828) in length, respectively. The sequences of both markers exhibited 99 and 100% identity, respectively, with sequences being more similar to those of M. javanica isolates from Brazil, Vietnam, and China. The confirmation of nematode species identity was performed by PCR species-specific sequence characterized amplified region (SCAR) using a primer set composed of Fjav (5′-GGTGCGCGATTGAACTGAGC-3′) and Rjav (5′-CAGGCCCTTCAGTGGAACTATAC-3′). The PCR amplification using SCAR produced a specific fragment of expected size (∼670 bp) for M. javanica (Donkers-Venne et al. 2000). In greenhouse tests, cockscomb Comum plants being maintained in pots containing sterilized soil were inoculated with 5,000 eggs and J2 of the original M. javanica population; a noninoculated control was included, and treatments were replicated 10 times. After 60 days, all inoculated plants showed reduced growth compared with the control. Galling symptoms on the roots were similar to those observed in field-grown plants, and the nematode reproduction factor (final population/initial population) was 20.5. The noninoculated plants did not present gall formation in the roots, and their development was not affected either. The morphological and molecular characteristics of reisolated root-knot nematodes were identical to those of M. javanica. These results confirmed the nematode’s pathogenicity to cockscomb. To our knowledge, this is the first report on M. javanica parasitizing cockscomb in Brazil; therefore, our findings are of great importance to Brazilian flower growers to help them establish management measures M. javanica.

Genetic Variability among Different Populations of Root Knot Nematodes Based on Their Encumbrance Response to Pasteuria Isolates Using PCR-RFLP

A great variable response was observed when PP-3 and PP-J encumbered with 116 populations of root knot nematode (RKN) at two different temperatures (25 ± 2°C and 30 ± 2°C) and concentrations (104 and 105 spores/ml). The PCR reaction amplified intergenic region between cytochrome oxidase subunit II gene (COII) and large subunit of rRNA gene (lrRNA) of the mitochondrial genome of different RKN species. The primer C2F3 and 1108 identified M. incognita with the highest frequency (52.6%) followed by M. javanica (36.8%) and M. arenaria (10.5%). The sizes of PCR products were 1.7 kb for M. incognita and M. javanica populations while populations of M. arenaria produced 1.1 kb fragment. The digestion with Hinf I yielded three different fragment length patterns on 1.5 % agarose gel. From current research it is concluded that intra-Meloidogyne genetic variability exist in RKN populations which have better encumbrance with P. penetrans.

Susceptibility of Crotalaria Species to Different Populations of Meloidogynejavanica

Crotalaria is one of the most widely used plants for the control of phytopathogenic nematodes. The plants act by inhibiting nematode multiplication, fixing atmospheric nitrogen, and improving soil quality. The pathogenicity of nematode populations can vary according to plant species. This study aimed to evaluate the response of different Crotalaria species to seven populations of Meloidogyne javanica. Crotalaria spectabilis, C. ochroleuca, C. juncea, and soybean (control) were inoculated with the nematode. Fresh root weight, root-knot index, total number of nematodes, nematode population density (number of nematodes per gram of fresh root), and reproductive factor (RF) were evaluated 60 days after inoculation. M. javanica populations varied in pathogenicity to all plants studied. Soybean was susceptible to all populations, and C. spectabilis and C. ochroleuca were resistant. C. juncea was susceptible to Mj-7 (RF=1.04). Mj-7 was the most pathogenic population.

Genetic diversity and phylogeny of South African Meloidogyne populations using genotyping by sequencing

Meloidogyne species cause great crop losses worldwide. Although genetic host plant resistance is an effective control strategy to minimize damage caused by Meloidogyne, some resistant genes are ineffective against virulent species such as Meloidogyne enterolobii. Detailed knowledge about the genetic composition of Meloidogyne species is thus essential. This study focused on genotyping-by-sequencing (GBS) and Pool-Seq to elucidate the genetic relation between South African M. enterolobii, M. incognita and M. javanica populations. Hence, 653 common single nucleotide polymorphisms (SNPs) were identified and used to compare these species at genetic level. Allele frequencies of 34 SNPs consistently differed between the three Meloidogyne species studied. Principal component and phylogenetic analyses grouped the M. enterolobii populations in one clade, showing a distant relation to the M. javanica populations. These two species also shared genetic links with the M. incognita populations studied. GBS has been used successfully in this study to identify SNPs that discriminated among the three Meloidogyne species investigated. Alleles, only occurring in the genome of M. enterolobii and located in genes involved in virulence in other animal species (e.g. a serine/threonine phosphatase and zinc finger) have also been identified, accentuating the value of GBS in future studies of this nature.

Heat stability of resistance in selected tomato breeding lines against Meloidogyne incognita and M. javanica populations under elevated soil temperatures

In tomato, the only commercially available source of resistance to root-knot nematodes (RKN) is the Mi-1 gene that confers resistance to Meloidogyne incognita, M javanica and M arenaria. However, its effectiveness was limited at higher soil temperatures. A study was initiated with the objective to check the durability of the potential resistance genes found in some tomato breeding lines after screening in controlled glasshouse conditions <= 27 degrees C by exposing them to higher soil temperatures at 28, 32 and 36 degrees C for 24 and 48 h periods. The aggressive Jittu and Babile M incognita and Jittu and Koka M javanica populations originally collected from Ethiopia were used. When seedlings reached the four-leaf stage, each tube was inoculated with 50 freshly (< 24 h) hatched infective second-stage juveniles (J2). Immediately after inoculation, the seedlings were exposed continuously for 24 and 48 h in a warm water bath at 28, 32 and 36 degrees C, respectively. A control was kept separately in ambient temperature (24 degrees C 2 degrees C). The external ambient temperature and the soil temperature inside the tube while in the water bath were simultaneously recorded using a TESTO data logger. Temperature, tomato breeding lines and time had a significant effect on the number of J2 of Jittu and Babile M incognita and Jittu and Koka M javanica populations that penetrated the roots. The utility of the potential resistance found in the breeding lines during the controlled growth chamber resistance screening experiment was limited at higher soil temperatures, especially at 32 and 36 degrees C. At 36 degrees C there was no significant difference found on the mean number of penetrated J2 of Jittu and Babile M incognita and Jittu and Koka M javanica populations inside the roots of all the tested breeding lines compared to 'Marmande' (a susceptible control) after 48 h of heat exposure after inoculation. More J2 were found in the roots of the tested breeding lines after 48 h compared to 24 h heat exposure after inoculation for each soil temperature level tested and for both populations of M incognita. It is clear from our observations that local tomato breeding lines with resistance potential can be used when soil temperatures remain below 32 degrees C. Differences were observed between breeding lines depending on the RKN population used at higher temperatures and this knowledge can help in further optimising the development of sustainable resistance under local Ethiopian circumstances.

Pangolin distribution and conservation status in Bangladesh.

Asian pangolins are a highly-threatened species group, mainly due to the perceived medicinal value of their scales. Increased demand from China has resulted in pangolins being the most trafficked mammal in the world. Three pangolin species are reported to occur in Bangladesh: Manis pentadactyla, M. crassicaudata, and M. javanica. No peer-reviewed studies exist detailing these species’ current distribution or status within Bangladesh. A literature review was conducted resulting in the clarification of conflicting reports and misidentified observations and specimen records. In this paper, we also report the current status of pangolins (Manis spp.) in Bangladesh based on semi-structured interviews, camera trapping, media queries, and field surveys employing traditional ecological knowledge and non-randomized transect surveys. Ethnozoological knowledge pertaining to the natural history of M. pentadactyla is also reported from experienced Mro tribal hunters. The critically endangered M. pentadactyla was verified to occur in northwest, northeast, and southeast Bangladesh in natural and degraded habitats. Interviews with the Mro tribe in the southeast indicate that pangolin populations there were likely extirpated in 2014 due to skilled commercial collection beginning in 2010. Evidence of extant M. crassicaudata and M. javanica populations remain unverified and questionable, and historical records of M. crassicaudata and M. javanica are likely a result of misidentification.

Resistance screening of breeding lines and commercial tomato cultivars for Meloidogyne incognita and M. javanica populations (Nematoda) from Ethiopia

Soil and root samples were collected from major tomato growing areas of Ethiopia during the 2012/2013 growing season to identify root-knot nematode problems. DNA-based and isozyme techniques revealed that Meloidogyne incognita and M. javanica were the predominant Meloidogyne species across the sampled areas. The aggressiveness of different populations of these species was assessed on tomato cultivars Marmande and Moneymaker. The two most aggressive populations of each species were selected and further tested on 33 tomato genotypes. The resistance screening and mechanism of resistance was performed after inoculation with 100 freshly hatched (<24 h) second-stage juveniles (J2). Eight weeks after inoculation the number of egg masses produced on each cultivar was assessed. For the resistance mechanism study, J2 penetration and their subsequent development inside the tomato roots were examined at 1, 2, 4 and 6 weeks after inoculation. On both cultivars Marmande and Moneymaker all M. incognita and M. javanica populations formed a high number of egg masses indicating highly aggressive behaviour. Populations from ‘Jittu’ and ‘Babile’ for M. incognita and ‘Jittu’ and ‘Koka’ for M. javanica were selected as most aggressive. None of the 33 tomato genotypes were immune for these M. incognita and M. javanica populations. However, several tomato genotypes were found to have a significant effect on the number of egg masses produced indicating possible resistance. For M. javanica populations there were more plants from cultivars or breeding lines on which no egg masses were found compared to M. incognita populations. The lowest number of egg masses for both populations of M. incognita was produced on cultivars Bridget40, Galilea, and Irma while for M. javanica it was on Assila, Eden, Galilea, Tisey, CLN-2366A, CLN-2366B and CLN-2366C. Tomato genotypes, time (weeks after inoculation) and their interaction were significant sources of variation for J2 penetration and their subsequent development inside the tomato roots. Differential penetration was found in breeding lines such as CLN-2366A, CLN-2366B and CLN-2366C, but many of the selected tomato genotypes resistance for the tested M. incognita and M. javanica populations were expressed by delayed nematode development. Therefore, developing a simple screening technique to be used by local farmers or extension workers is crucial to facilitate selection of a suitable cultivar.

Host-status of selected South African commercial potato cultivars to Meloidogyne incognita and Meloidogyne javanica

The use of root-knot (Meloidogyne spp.) nematode resistance in most crops remains the most preferred option, but there are no known genotypes with nematode resistance in wild and cultivated potato (Solanum tuberosum) plants. As part of concerted efforts to search for nematode resistance, the objective of this study was to determine the hoststatus of high yielding commercial potato cultivars in South Africa to M. incognita and M. javanica populations. Potato cultivars Sifra, Lanorma, Innovator, Uptodate and FL2108.2006.1 were each inoculated with 5000 eggs and second-stage juveniles (J2) in separate trials over two seasons. Fifty-six days after inoculation, the reproductive potential (RP = eggs and J2/g roots) of nematodes on each cultivar was assessed. In M. incognita, RP values ranged from 79.28 to 197.11 in Experiment 1 and from 47.31 to 1327 in Experiment 2 on potato cultivars. Similarly, in M. javanica trial, RP values ranged from 6.13 to 327.02 and from 16.88 to 237.42 in the respective experiments. In conclusion, all tested high yielding commercial potato cultivars in South Africa were excellent hosts to M. incognita and M. javanica population.

Genetic diversity of Meloidogyne spp. parasitising potato in Brazil and aggressiveness of M. javanica populations on susceptible cultivars

Root-knot nematodes (Meloidogyne spp.) significantly impact potato production worldwide and in Brazil they are considered one of the most important group of nematodes affecting potatoes. The objectives of this study were to survey Meloidogyne spp. associated with potatoes in Brazil, determine their genetic diversity and assess the aggressiveness of M. javanica on two susceptible potato cultivars. Fifty-seven root-knot nematode populations were identified using esterase phenotyping, including Meloidogyne javanica, M. incognita, M. arenaria and M. ethiopica. Overall, root-knot nematodes were present in ca 43% of sampled sites, in which M. javanica was the most prevalent species, and the phenotypes Est J3, J2a and J2 occurred in 91.2, 6.7 and 2.1% of the positive samples, respectively. Other species, such as M. incognita, M. arenaria and M. ethiopica, were found less frequently and occurred at rates of 6.4, 4.3 and 2.1% of the samples, respectively. Sometimes, M. javanica was found in mixtures with other root-knot nematodes in ca 10.6% of sites containing Meloidogyne. After confirming the identification of 17 isolates of M. javanica and one isolate each of M. incognita, M. arenaria and M. ethiopica by SCAR markers, the populations were used to infer their genetic diversity using RAPD markers. Results revealed low intraspecifc genetic diversity among isolates (13.9%) for M. javanica. Similarly, M. javanica sub-populations (J2a) clustered together (81% of bootstrap), indicating subtle variation from typical J3 populations. The aggressiveness of four populations of M. javanica from different Brazilian states on two susceptible potato cultivars was tested under glasshouse conditions. Results indicated differences in aggressiveness among these populations and showed that potato disease was proportional to nematode reproduction factor.

Developing an effective glyphosate application technique to control Bischofia javanica Blume, an invasive alien tree species in the Ogasawara Islands

Bischofia javanica is a non-native tree species in Japan's Ogasawara Islands, where it threatens native tree species due to its rapid propagation and growth. An effective method is needed to limit the expansion of B. javanica populations and to conserve the natural forest ecosystem of the islands. For this purpose, we examined the effectiveness of a new application technique for the herbicide glyphosate on B. javanica. In this method, glyphosate solution is directly injected into holes drilled in the stem, and each hole is then plugged with a cork stopper to prevent loss of the solution, namely the drill-and-plug method. We also developed an allometric regression model linking stem diameter with total aboveground biomass (AGB) to estimate the necessary herbicide dosage. Our results suggest that between 0.1 and 0.5 g kg−1 (active ingredient per unit AGB) is required to control most B. javanica trees. Verification of the drill-and-plug method using the minimum dosage (0.1 g kg−1) showed that most of the herbicide-treated trees were killed. These results suggest that the drill-and-plug method can help control the B. javanica invasion of the Ogasawara Islands.