scholarly journals First report of southern root-knot nematode, Meloidogyne incognita, infecting Isatis indigotica Fortune in Anhui Province, China

Plant Disease ◽  
2021 ◽  
Author(s):  
Zhijiao Zhao ◽  
Xuebing Zhao ◽  
Yaxing Feng ◽  
Xaofeng Zhu ◽  
Yuanyuan Wang ◽  
...  
Keyword(s):  
Meloidogyne Incognita ◽  
18S Rdna ◽  
Anhui Province ◽  
Molecular Characteristics ◽  
Isatis Indigotica ◽  
Nematode Reproduction ◽  
Lateral Field ◽  
Egg Masses ◽  
First Report ◽  
Egg Density

Isatis indigotica Fortune, widely cultivated in China, is an important Chinese herbal medicine, mainly used to treat cold and fever. In October 2020, galls (Fig. 1), as many as 65 per root, were observed on the roots of I. indigotica in Taihe, Anhui Province, China (117°21'19.5"N, 32°57'59.5"E), and samples were taken. The infected plants were weak, and the leaves are wilting. Second-stage juveniles (J2s) were dissected from the egg masses released by females. Excretory pores of females were located nearby median bulb (Fig. 2A). The dorsal arch of the perineal pattern (n = 10) of the female was elliptical, and the dorsal arch was relatively high with smooth to wavy lines (Fig. 2B). Morphometrics of females (n=10): body length (L) = 595.5 ± 24.0 (570.0-620.5) μm, body width (W)= 350.5 ± 30.0 (320.0-390.5) μm, stylet length = 13.6 ± 0.7 (12.1-15.4) μm (Fig. 2A), and the distance from dorsal esophageal gland orifice to base of stylet (DGO) = 3.5 ± 0.2 (2.8-4.0) μm (Fig. 2B). J2s (n = 20) had the following characteristics: L = 383.2 ± 12.5 (337-430) μm (Fig. 2C), a = 22.0 ± 1.1 (20.3-24.4) μm, c = 8.4 ± 0.5 (7.5-10.5) μm, stylet length = 12.4 ± 1.5 (10.1-14.6) μm, DGO = 2.9 ± 0.6 (2.0-3.6) μm (Fig. 2D), tail length = 39.5 ±3.4 (32.0-48.5) μm and hyaline tail terminus = 10.5 ± 0.5 (9.5-11.2) μm (Fig.1E). There were four lines on the lateral field of J2s (Fig. 2F). Females and J2s obtained from galls had uniform morphological and molecular characteristics were confirmed to be Meloidogyne incognita. Live J2s were detected in all soil samples with a mean of 120 ± 15 J2s/100 ml of soil. Five 4-week-old I. indigotica plantlets, grown in pots (500cm3) with sterilized soil were inoculated with 1000 J2s from egg masses per pot and5 non-inoculated pots were used as control. Plants were well maintained under 25 ± 3°C in the greenhouse. Three plants were gently removed from the pots 30 days after inoculation, and an average of 50 galls per root was observed on the roots, and the resulting nematode reproduction factors (RF = final egg density ÷ 1,000, initial egg density) of 3.2, suggested that I. indigotica is a good host for M. incognita (Mojtahedi, 1988). There were no significant differences in main measurements and morphological characteristics between the Taihe population of M. incognita and that represented in "CIH descriptions of plant-parasitic nematodes" (Orton Williams, 1973). DNA was extracted from 5 single J2s, and ITS and 18S rDNA gene was amplified using the primer pair 18S/26S and 18s1.2a/18sr2b (Bernard et al. 2010; Vrain et al. 1992). The sequence of 18S rDNA (MW875892) was submitted to GenBank. Comparisons showed a sequence identity of greater than 99.8% for Meloidogyne incognita (MF177719.1). The rDNA sequences of M. incognita, M. hapla, M. javanica and M. arenaria are so homologous that rDNA-based differentiation is difficult. The SCAR primers can successfully distinguish M. incognita, M. hapla, M. javanica and M. arenaria. Five species-specific primer sets (Finc/Rinc; MORF-F/MTHIS-R; Jmv-F/Jmv-R; Far/Rar and Fjav/Rjav, Stanton et al. 1997; Wishart et al. 2002; Zijlstra et al. 2000) were used to species-specifically distinguish within the genus. The results (＋, ＋, －, －, －) proved that the Taihe population belonging to M. incognita. To our knowledge, this is the first report of M. incognita parasitizing I. indigotica. This finding may be important to medicinal plant industry, since M. incognita is one of the most harmful nematode pests in the world and would cause severe damage to I. indigotica.

scholarly journals First Report of Brown Blight Disease Caused by Colletotrichum gloeosporioides on Camellia sinensis in Anhui Province, China

Plant Disease ◽  
2014 ◽  
Vol 98 (2) ◽  
pp. 284-284 ◽  
Author(s):  
M. Guo ◽  
Y. M. Pan ◽  
Y. L. Dai ◽  
Z. M. Gao
Keyword(s):  
Camellia Sinensis ◽  
Colletotrichum Gloeosporioides ◽  
Tea Plant ◽  
Anhui Province ◽  
Molecular Characteristics ◽  
Fluorescent Light ◽  
Distilled Water ◽  
Conidial Suspension ◽  
First Report ◽  
Twig Blight

Yellow Mountain fuzz tip, a cultivar of Camellia sinensis (L.) Kuntze, is commonly grown in the Yellow Mountain region in Anhui Province of China. During 2011 to 2012, leaf and twig blight on tea plants occurred from July to September in growing regions. Symptoms of blight on leaves of infected plants were detected in 30 to 60% of the fields visited and up to 500 ha were affected each year. Symptoms began as small, water-soaked lesions on young leaves and twigs and later became larger, dark brown, necrotic lesions, 1 to 3 mm in diameter on leaves and 2 to 5 mm long on twigs. To determine the causal agent, symptomatic leaf tissue was collected from plants in Gantang and Tangkou townships in September 2012. Small pieces of diseased tea leaves and twigs were surface-disinfested in 2% NaClO for 3 min, rinsed twice in distilled water, plated on potato dextrose agar, and incubated at 28°C for 5 days. Eleven isolates were recovered and all cultures produced white-to-gray fluffy aerial hyphae and were dark on the reverse of the plate. The hyphae were hyaline, branching, and septate. Setae were 2- to 3-septate, dark brown, acicular, and 78.0 to 115.0 μm. Conidiogenous cells were hyaline, short, branchless, cylindrical, and 11.3 to 21.5 × 4.2 to 5.3 μm. Conidia were hyaline, aseptate, guttulate, cylindrical, and 12.5 to 17.3 × 3.9 to 5.8 μm. Appresoria were ovate to obovate, dark brown, and 8.4 to 15.2 × 7.8 to 12.9 μm. DNA was amplified using the rDNA-ITS primer pair ITS4/ITS5 (3), glyceraldehyde-3-phosphate dehydrogenase gene (GAPDH) primer pair GDF/GDR (2) and beta-tubulin 2 gene (Tub2) primer pair Btub2Fd/Btub4Rd (4). Sequences (GenBank Accession Nos. KC913203, KC913204, and KC913205) of the 11 isolates were identical and revealed 100% similarity to the ITS sequence of strain P042 of Colletotrichum gloeosporioides (EF423527), 100% identity to the GAPDH of isolate C07009 of C. gloeosporioides (GU935860), and 99% similarity to Tub2 of isolate 85 of C. gloeosporioides (AJ409292), respectively. Based on the above data, the 11 isolates were identified as C. gloeosporioides (Penz.) Penz. & Sacc. To confirm pathogenicity, Koch's postulate was performed and 4 ml of conidial suspension (1 × 105 conidia/ml) of each of the 11 isolates was sprayed on five leaves and five twigs per plant on four 12-month-old Yellow Mountain fuzz tip plants. Control plants were sprayed with distilled water. The inoculated plants were maintained at 28°C in a greenhouse with constant relative humidity of 90% and a 12-h photoperiod of fluorescent light. Brown necrotic lesions appeared on leaves and twigs after 7 days, while the control plants remained healthy. The experiments were conducted three times and the fungus was recovered and identified as C. gloeosporioides by both morphology and molecular characteristics. Tea plant blight caused by C. gloeosporioides was identified in Brazil (1), but to our knowledge, this is the first report of C. gloeosporioides causing tea leaf and twig blight on Yellow Mountain fuzz tip plants in Anhui Province of China. References: (1) M. A. S. Mendes et al. Page 555 in: Embrapa-SPI/Embrapa-Cenargen, Brasilia, 1998. (2) M. D. Templeton et al. Gene 122:225, 1992. (3) T. J. White et al. Page 315 in: PCR Protocols: A Guide to Methods and Applications. Academic Press, San Diego, 1990. (4) J. H. C. Woudenberg et al. Persoonia 22:56, 2009.

scholarly journals First Report of Meloidogyne incognita on Cardamine Violifohia in China

Plant Disease ◽  
2021 ◽  
Author(s):  
Rui Liu ◽  
Hongqing Yin ◽  
Lin Li ◽  
Kaiwei Huang ◽  
Huixia Li ◽  
...  
Keyword(s):  
Body Length ◽  
Meloidogyne Incognita ◽  
Uv Light ◽  
Morphological Characteristics ◽  
Tail Length ◽  
Nematode Species ◽  
Economic Losses ◽  
Egg Masses ◽  
First Report ◽  
Stylet Length

Cardamine violifohia is an economically-important medicinal plant, and also a valuable plant for strong ability to accumulate selenium (Se) (Ebba et al. 2020). It is not only be used to extract selenium protein and selenium polysaccharide, but also widely used to develop selenium-supplement reagent. In September 2020, root-knot nematodes (RKN; Meloidogyne spp.) infection experiments showed that galls and egg masses were observed on the roots of numerous C. violifolia plants in Enshi (30°32′25.67″ N; 109°48′48.46″ E), Hubei Province, China. Meanwhile, the overground plants of C. violifohia were stunted and leaves were yellow. Almost 5% C. violifohia plants were affected by the disease. The roots with galls were collected, and nematodes were dissected and extracted (Fig. S1). Based on phytopathological clinic, the number of galls on each plant was 91.87 ± 19.01, and egg masses was 15.27 ± 5.36 (n = 15). Nematodes and galls were collected from soil and infected roots (Barker 1985). The morphological diagnostic of the nematode species was measured as follows. Measurements of adult females (n=20), body length = 628.15 ± 73.69 μm, width = 356.77 ± 36.72 μm, stylet length = 15.58 ±0.93 μm. Meanwhile, a high and trapezoidal dorsal arch with thick striations was observed in the perineal region of females. Second-stage juveniles (J2s) (n=20): body length = 377.09 ± 18.19 μm, body width = 15.64 ± 1.24 μm, stylet length = 13.31 ± 1.04 μm, tail length = 42.49 ± 4.64 μm, hyaline tail terminus = 12.35 ± 2.02 μm and presented well developed esophageal glands. Eggs (n=20): length = 80.81 ± 3.47 μm, and width = 37.09 ± 2.98 μm. All the morphological characteristics of the identified species were consistent with the descriptions of Meloidogyne incognita (Kofoid & White, 1919) Chitwood, 1949 (Whitehead, 1968). Molecular identification was carried out by PCR with the M. incognita-specific primers Mi-F/Mi-R (Meng et al. 2004) and 28S rDNA D2/D3 region primers MF/MR (Hu et al. 2011). The target fragments of 955 bp and 478 bp amplified by of the primer pairs Mi-F/Mi-R and MF/MR were observed under a UV light, which confirmed that these nematodes collected from C. violifohia were M. incognita (Fig. S2). Fragments were, sequenced (MZ596342 and MZ566843, respectively) and aligned with available sequences on NCBI, which were 100% identical to the MK410954, MN728679, and MK410953, MF177882 M. incognita sequences, respectively. Pathogenicity testing was conducted to perform Koch’s postulates in a greenhouse by inoculation of 500 J2s from the original population into C. violifohia seedlings (n = 30, 5-6 leaves stage). After 7 weeks, all inoculated plants exhibited the same symptoms that observed in the field initially. Different life stages of M. incognita were observed in dissected galled tissues. The average reproductive factor was 37.30 ± 6.13, which is considered as the pathogenicity of M. incognita to C. violifohia. Therefore, C. violifohia is a suitable host for M. incognita in China. The growers should be informed of the current findings to avoid serious economic losses that might be caused by this pathogenic nematode, and prepare for proper management action. To our knowledge, this is the first report of M. incognita infecting C. violifohia in China.

scholarly journals First Report of Heterodera ripae on Common Nettle in Spain

Plant Disease ◽  
2011 ◽  
Vol 95 (7) ◽  
pp. 883-883
Author(s):  
J. López-Robles ◽  
G. Sacristán-Pérez-Minayo ◽  
C. Olalla-Gómez
Keyword(s):  
Body Length ◽  
Cannabis Sativa ◽  
Restriction Enzymes ◽  
Pharmaceutical Products ◽  
Morphological Data ◽  
Wild Plants ◽  
Molecular Characteristics ◽  
Cyst Nematodes ◽  
Lateral Field ◽  
First Report

Soil and root samples were collected from May to October 2010 from cultivated and wild plants during a survey for hop cyst nematodes. Cyst nematodes were detected in roots of common nettle (Urtica dioica L.) with severe plant yellowing in four natural areas of León and Burgos provinces, Spain, where common nettle is grown in organic farming systems as a substrate for pharmaceutical products. Cysts were isolated by flotation and sieving methods. Cysts and juveniles were analyzed by morphological and molecular methods. The cyst nematodes obtained from soil and plant samples from all four locations had uniform morphological and molecular characteristics that differed from those of Heterodera humuli. Cysts (n = 25) had the following characteristics: lemon shaped, yellow to pale brown; cyst wall with ridges forming an irregular zigzag pattern; young cysts covered by subcrystalline layer; vulval cone bifenestrate with circular or subcircular fenestrae; bullae absent; underbridge weak; body length (not including the neck) ranging from 295 to 489 μm (mean of 418 μm); body width ranging from 208 to 375 μm (mean of 310 μm); fenestrate length of 39 to 58 μm (mean of 46.5 μm) and width of 25.2 to 30.9 μm (mean of 25.1 μm); underbridge length from 51 to 90 μm (mean of 69.2 μm); and vulval slit length from 26 to 40 μm (mean of 33 μm). J2 (n = 20) had the following characteristics: body length ranging from 338 to 380 μm (mean of 359.3 μm); stylet length from 21 to 24 μm (mean of 22.1 μm) with knobs rather wide and slightly projecting anteriorly; tail conical with a length of 41 to 52.5 μm (mean of 45.6 μm) and hyaline part of tail ranging from 18 to 25 μm (mean of 23.3 μm); lateral field with four lines. All morphological data and characters were consistent with those of H. ripae (1). DNA from single cysts was extracted to amplify the internal transcribed spacer (ITS) region of rDNA by PCR with forward primer TW81 (5′-GTTTCCGTAGGTGAACCTGC-3′) and reverse primer AB28 (5′-ATATGCTTAAGTTCAGCGGGT-3′) (2). The PCR product was digested by restriction enzymes (AluI, CfoI, HaeI, HinfI, PstI, RsaI, TaqI, and Tru9I) to obtain restriction fragment length polymorphism profiles (2). ITS products cloned and assayed using the ABI PRISM 3100 Genetic Analyzer (Applied Biosystems, Salamanca, Spain) were subjected to a database search using BLAST (National Centre for Biotechnology Information) to confirm the identification. These sequences exhibited 99.0% similarity with that of a H. ripae isolate from Germany (GenBank Accession No. AF274407.1). In glasshouse proofs of pathogenicity with these populations of H. ripae, 25 full cysts placed in nylon net bags were inoculated in 9-cm-diameter pots with 10 replicates per plant. After 12 weeks, soil from each pot was dried and cysts extracted. Cysts did not develop on roots of common hop (Humulus lupulus L.) and hemp (Cannabis sativa L.), but in common nettle there was an increase in nematode populations, with all plants severely stunted and yellowing, which confirmed the nematodes' pathogenicity. H. ripae has been previously reported in Russia, Estonia, Latvia, Armenia, Moldova, Ukraine, Bulgaria, Slovakia, Germany, and Belgium (1). To our knowledge, this is the first report of H. ripae in Spain. The identification of H. ripae in nettle fields is important in this region where it could cause large yield reductions if not properly managed. References: (1) S. A. Subbotin et al. Russ. J. Nematol. 5:143, 1997. (2) S. A. Subbotin et al. Nematology 5:515, 2003.

scholarly journals Seed treatment affects Meloidogyne incognita penetration, colonization and reproduction on cotton

2010 ◽  
Vol 40 (6) ◽  
pp. 1428-1430 ◽  
Author(s):  
Rosana Bessi ◽  
Fernando Ribeiro Sujimoto ◽  
Mário Massayuki Inomoto
Keyword(s):  
Root System ◽  
Meloidogyne Incognita ◽  
Seed Treatment ◽  
Crop Management ◽  
Environmental Aspects ◽  
Nematode Reproduction ◽  
Egg Masses ◽  
Second Stage ◽  
Greenhouse Experiments ◽  
Current Practices

The effect of abamectin, applied as seed treatment, on Meloidogyne incognita penetration, colonization, and reproduction on cotton was evaluated in two greenhouse experiments. Second stage juveniles (J2) penetration was evaluated 3, 9 and 15 days after germination (dag), whereas the nematode colonization was evaluated 27dag, by counting the total number of galls and egg masses per root system. Eggs and J2 were extracted from the roots to assess the nematode reproduction at 50 and 100dag. The seed treatment caused a decrease in J2 penetration in the roots, resulting in lower colonization and reproduction of M. incognita. These findings are discussed considering the environmental aspects of abamectin in the soil and the current practices for the crop management.

scholarly journals Resistance screening of lentil cultivars against the root-knot nematode Meloidogyne incognita

2018 ◽  
Vol 11 (1) ◽  
pp. 9-18 ◽  
Author(s):  
T. Ansari ◽  
M. Asif ◽  
M.A. Siddiqui
Keyword(s):  
Plant Growth ◽  
Meloidogyne Incognita ◽  
Growth Parameters ◽  
Dry Weight ◽  
Fresh Weight ◽  
Root Knot Nematode ◽  
Nematode Reproduction ◽  
Egg Masses ◽  
Moderately Resistant ◽  
Reduction Percentage

SummaryThe root-knot nematodeMeloidogyne incognitais a major soil parasite of lentil crops. Increasing restrictions of chemical nematicides have triggered a growing attention and interest in alternate root-knot nematode management. The present study was conducted to examine the level of resistance and/or susceptibility of five lentil cultivars (PL-456, KLS-218, Desi, DPL-62, Malika), grown in pots, against the root-knot nematodeM. incognita. Root-knot nematode reproduction and host damage were assessed by recording the nematode infestation levels and reduction percentage of plant growth parameters. Nematode response and plant growth differentiated amongst the lentil cultivars. None of the cultivars was found immune or highly resistant. The cultivar Malika was found moderately resistant as it showed the lowest number of galls and egg masses/root as well as the lowest reduction of plant fresh weight (10.4%) and dry weight (6.9%). On the other hand, the cultivar Desi manifested the highest susceptibility exhibiting the highest number of galls and egg masses. There was a significantly negative correlation between the number of galls and plant growth parameters (plant fresh and dry weight and plant height).

scholarly journals First Report of the Cyst Nematode (Heterodera elachista) on Rice in Hunan Province, China

Plant Disease ◽  
2012 ◽  
Vol 96 (1) ◽  
pp. 151-151 ◽  
Author(s):  
Z. Ding ◽  
J. Namphueng ◽  
X. F. He ◽  
D. L. Peng ◽  
W. K. Huang
Keyword(s):  
Body Length ◽  
Leaf Length ◽  
Rice Fields ◽  
Its Sequences ◽  
Hunan Province ◽  
Universal Primers ◽  
Molecular Characteristics ◽  
Cyst Nematodes ◽  
Lateral Field ◽  
First Report

During a survey for the cyst nematodes (Heterodera elachista) from May to June of 2011, cyst nematodes were detected in hilly rice fields in five counties (Changsha, Pingjiang, Hengdong, Shaoyang, and Xiangxiang) of Hunan Province, China. Cyst nematodes obtained from soil samples and harvested rice root samples at these five locations had uniform morphological and molecular characteristics. Cysts (n = 20) had the following characteristics: spherical to lemon shaped, vulval cone ambifenestrate, vulval bridge narrow, medium sized underbridge, with a few dark brown bullae, body length (not including the neck) ranging from 354 to 586 μm (mean = 438.9 μm, st. dev. = 63.7); body width ranged from 283 to 495 μm (354.5, 60.1); fenestrate length of 30 to 50 μm (37.4, 5.0) and width of 25 to 47.5 μm (35.1, 7.1); underbridge length from 70 to 95 μm (83.4, 8.2); and vulval slit length from 30.3 to 55.5 μm (40.3, 9.1). J2 (n = 20) had the following characteristics: body length ranging from 404 to 525 μm (mean of 461.6 μm, st. dev. = 34.5); stylet length from 20 to 25 μm (22.5, 1.1) with rounded knob; tail length of 60 to 87.5 μm (67.3, 6.9); and hyaline terminal tail ranged from 30 to 50 μm (37.5, 6.4); lateral field with three lines. The mean and range of J2 were longer than those reported for H. elachista by Nobbs et al. (1) and Tanha et al. (4), but other morphological character values were within the range of those reported (4). DNA from a single cyst was extracted, the rDNA-internal transcribed spacer (ITS) and D2/D3 fragments of the 28S RNA were amplified with universal primers TW81 and AB28, D2A and D3B, respectively. Five ITS sequences (JN202913, JN202914, JN202915, JN202916, and JN202917) and five D2/D3 sequences (JN202918, JN202919, JN202920, JN202921, and JN202922) from nematode samples collected in Changsha, Hengdong, Shaoyang, Pingjiang, and Xiangxiang, respectively, were submitted to GenBank. These ITS sequences were remarkably similar to each other and exhibited 98.6 to 99.3% similarity with that of H. elachista isolate from Iran (AF498391), and 98.8 to 99.4% similarity with that of H. elachista isolates from Ningxia Province, China (HM560778 and HM560779). The D2/D3 sequences exhibited 99.7 to 100% similarity with that of H. elachista isolates from Ningxia Province, China (HM560842 and HM560843). These characteristics indicated that the five populations were H. elachista belonging to the ‘cyperi’ group (1,2). In glasshouse evaluations of the pathogenicity of these isolates, 500 second-stage juveniles were inoculated onto five 20-day-old seedlings of rice (Weiyou No.227) in 4.5-cm diameter 30-cm high tubes with six replicates. After 8 weeks, stunting and reduction of leaf length were observed and cysts were extracted from dried soil of each tube using sieves. Brown cysts (92 to 204) and white females (14 to 40) were obtained from inoculated rice from each tube. H. elachista can decrease yield by 7 to 19% and has the most severe impact during the later stages of plant growth (3). H. elachista has been previously identified from rice fields in Japan and Iran (3). To our knowledge, this is the first report of H. elachista on rice in Hunan Province, China. References: (1) J. M. Nobbs et al. Fundam. Appl. Nematol. 15:551, 1992. (2) S. A. Subbotin et al. Mol. Phylogenet. Evol. 21:1, 2001. (3) S. A. Subbotin et al. Systematics of Cyst Nematodes (Nematoda: Heteroderinae). Volume 8 Part B. Brill, Leiden, the Netherlands, 2010. (4) M. Z. Tanha et al. Nematology 5:99, 2003.

scholarly journals First Report of the Cyst Nematode (Heterodera filipjevi) on Wheat in Henan Province, China

Plant Disease ◽  
2010 ◽  
Vol 94 (10) ◽  
pp. 1262-1262 ◽  
Author(s):  
D. L. Peng ◽  
W. X. Ye ◽  
H. Peng ◽  
X. C. Gu
Keyword(s):  
Body Length ◽  
Tail Length ◽  
The United States ◽  
Henan Province ◽  
Universal Primers ◽  
Heterodera Avenae ◽  
Molecular Characteristics ◽  
Cyst Nematodes ◽  
Lateral Field ◽  
First Report

During a survey for cereal cyst nematodes from May to June of 2009, cyst nematodes were detected in four wheat-growing areas (Liying, Xuchang, Weihui, and Yanjing) of Henan Province, China. The main wheat cultivar affected was Wenmai No.4. Almost 5.3 million ha of winter wheat are grown in Henan Province and 73% of the fields surveyed were found to be infested with Heterodera avenae (2). The affected wheat fields had stunted patches. Stunted seedlings had chlorotic or necrotic lower leaves, few or no tillers, and bushy, light brown roots leading to typical witches'-broom symptoms resulting from increased rootlet emergence at the nematode invasion sites. Individual roots had a knotted appearance. Cyst nematodes obtained from soil samples and plant samples at these four locations differed from those of H. avenae and had uniform morphological and molecular characteristics. Cysts were lemon shaped and bifenestrate, with an underbridge and strongly developed bullae. The lateral field of second-stage juveniles (J2) consisted of four incisures. These characteristics indicated that the four populations were H. filipjevi, a member of the ‘H. avenae Group’ of cereal cyst nematodes (1). Key morphological features were determined for cysts and J2. Cysts (n = 15) had the following characteristics, in addition to those described above: light brown color; bifenestrate vulval cone with horseshoe-shaped fenestrate; body length (not including the neck) ranged from 690 to 790 μm (mean of 750 μm); body width ranged from 410 to 640 μm (mean of 540 μm); neck length ranged from 86 to 100 μm (mean of 96 μm); fenestrate length of 59 to 70 μm (mean of 67.7 μm) and width of 31.3 to 36.7 μm (mean of 35.2 μm); underbridge length from 59 to 71 μm (mean of 68 μm); and vulval slit from 6.9 to 8.6 μm (mean of 7.9 μm). J2 (n = 10) had the following characteristics: body length ranged from 540 to 580 μm (mean of 550 μm); stylet length from 22.5 to 24.5 μm (mean of 23.5 μm) with anchor-shaped basal knobs; tail length of 52.5 to 62.5 μm (mean of 57.7 μm); and hyaline terminal tail ranged from 32 to 39 μm (mean of 33.8 μm). The tail had a sharp terminus. Amplification of the rDNA-internal transcribed spacer (ITS) region with primers TW81 and AB28 yielded a PCR fragment of 1,054 bp (3). Amplification of the D2/D3 fragments of the 28S RNA with universal primers D2A (5′-ACA AGT ACC GTG AGG GAA AGT TG-3′) and D3B (5′-TCG GAA GGA ACC AGC TAC TA-3′) yielded a PCR fragment of 782 bp. Digestion patterns of the ITS PCR fragments with AluI, CfoI, HifI, SatI, PstI, RsaI, TaqI, and Tru9I showed restriction profiles identical to that of H. filipjevi (3,4). Four ITS sequences (GU083595, GU083596, HM147944, and HM147945) and four D2D3 sequences (GU083592, GU083593, GU083594, and GU083597) from nematode samples collected in Liying, Xuchang, Weihui, and Yanjing, respectively, were submitted to GenBank. These sequences exhibited 99.4% similarity with that of H. filipjevi isolates from Germany (AY148400), Italy (AY347922), Russia (AY148401), Spain (AY148399), Tadzhikistan (AY148402), Turkey (AY148398 and AY148397), the United Kingdom (AY148403 and AF274399), and the United States (GU079654). To our knowledge, this is the first report of H. filipjevi in China. References: (1) Z. A. Handoo. J. Nematol. 34:250. 2002. (2) D. L. Peng et al. Proc. 1st Workshop Internat. Cereal Cyst Nemat. Initiative, Antalya Turkey, p. 29, 2009. (3) S. A. Subbotin et al. Nematology 1:195, 1999. (4) G. Yan and R. W. Smiley. Phytopathology 100:216, 2010.

scholarly journals Effect of Individual, Simultaneous and Sequential Inoculation of Pseudomonas fluorescens and Meloidogyne incognita on Growth, Biochemical, Enzymatic and Nonenzymatic Antioxidants of Tomato (Solanum lycopersicum L.)

Plants ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 1145
Author(s):  
Ahmed Noureldeen ◽  
Mohd Asif ◽  
Taruba Ansari ◽  
Faryad Khan ◽  
Mohammad Shariq ◽  
...  
Keyword(s):  
Antioxidant Enzymes ◽  
Pseudomonas Fluorescens ◽  
Solanum Lycopersicum ◽  
Meloidogyne Incognita ◽  
Interactive Effects ◽  
Nematode Reproduction ◽  
Solanum Lycopersicum L ◽  
Defensive Enzymes ◽  
Sequential Inoculation ◽  
Nonenzymatic Antioxidants

This study was conducted on tomato (Solanum lycopersicum cv. K-21) to investigate the bioprotective nature of Pseudomonas fluorescens and its interactive effects with Meloidogyne incognita in terms of growth biomarkers, changes in biochemical attributes and modulation in antioxidant enzymes of the tomato plant. In this study, we grew tomato plants with M. incognita and P. fluorescens in separate pots, simultaneously and sequentially (15 days prior or post) after 15 days of seed sowing. The sequential inoculation of Mi15→Pf maximally increased the root-knot index and decreased the nematode population. It was also noted that inoculation suppressed the plant growth biomarkers in comparison to control. However, maximum suppression in nematode reproduction and increment in growth and physiological attributes were observed when P. fluorescens was applied 15 days prior to the nematode (Pf15→Mi) as compared to control. All the treatments showed an increase in antioxidant enzymes. Expression of phenol content and defensive enzymes such as peroxidase (POX) and superoxide dismutase (SOD) increased, in contrast to a significant reduction in malondialdehyde (MDA) and hydrogen peroxide (H2O2) contents when compared with the untreated inoculated plants. However, the highest levels of POX and SOD, and a lowest of phenol, MDA and H2O2 were displayed in the treatment Pf15→Mi, followed by Mi+Pf and Mi15→Pf.

Quantitative trait loci mapping of Meloidogyne incognita and M. hapla resistance in a recombinant inbred line population of soybean

Nematology ◽  
2018 ◽  
Vol 20 (6) ◽  
pp. 525-537
Author(s):  
Chunjie Li ◽  
Jialin Wang ◽  
Jia You ◽  
Xinpeng Wang ◽  
Baohui Liu ◽  
...  
Keyword(s):  
Quantitative Trait Loci ◽  
Inbred Line ◽  
Recombinant Inbred Line ◽  
Meloidogyne Incognita ◽  
Qtl Analysis ◽  
Recombinant Inbred Line Population ◽  
Quantitative Trait ◽  
Recombinant Inbred ◽  
Nematode Reproduction ◽  
Root Response

Summary A recombinant inbred line population of soybean (Glycine max) was utilised to identify the quantitative trait loci (QTLs) determining the response to infection by two root-knot nematode species, Meloidogyne incognita and M. hapla, in glasshouse assays. QTL analysis detected seven major and four minor QTLs on seven soybean chromosomes ((Chrs) 1, 7, 8, 10, 14, 18, 20) explaining 6-41% phenotypic variance (PVE) for M. incognita root response and nematode reproduction. Three of the major QTLs, on Chrs 7, 10 and 18, were confirmed in previous reports and two major QTLs on Chrs 14 and 20 were detected for the first time. The QTL analysis with M. hapla provides the first report of a major QTL region mapped on Chr 7, explaining 70-82% PVE in M. hapla root response and nematode reproduction. These novel identified QTLs with flanking markers will be helpful in marker-assisted breeding for nematode resistance in soybean.

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