PLANT PARASITIC NEMATODES ASSOCIATED WITH BRINJAL (SOLANUM MELONGENA) IN SOME AREAS OF BANGLADESH
Sharmin Afrose, I. H. Mian, M. Z. Alam and Rayhanur Jannat. 2014. Plant parasitic nematodes associated with brinjal (Solanum melongena) in some areas of Bangladesh. Bangladesh J. Plant Pathol. 30(1&2):29-37.
A survey was conducted during 2011-2014 to identify plant parasitic nematodes associated with rhizosphere soils and roots of brinjal (Solanum melongena). Soil and root samples were collected from brinjal fields in the districts of Gazipur, Tangail, Kishoregonj, Manikgonj and Mymensingh. The nematode was extracted following Baermann Funnel technique. Temporary mounts of the extracted nematodes were prepared and morphological characters and necessary morphometrics were determined uncer a compound microscope. Based on morphological characters and morphometrics, nematodes associated soil and roots of brinjal were identified up to genera or species level using appropriate key books. The plant parasitic nematodes associated with rhizosphere soils and roots of brinjal were Aphelenchus avenae, Cephalenchus emerginatus, Heli-cotylenchus indicus, Hoplolaimus indicus, Meloidogyne incognita, Pratylenchus pratensis, Pratylenchus zeae, Tylenchorhynchus claytoni, Tylenchus sp., Ditylenchus melongena, Xiphinema americanum and Zygotylenchus guevarai. Except M. incognita other nematode species of brinjal have been reported first time from Bangladesh. Morphological characteristics have been described.
Brinjal or eggplant (Solanum melongena) is a popular vegetable and important cash crop in Bangladesh. Per hectare yield of the crop is very low in comparison to China, India and world average (Anon. 2004a). Brinjal is attacked by more than 40 species of plant parasitic nematodes throughout the world (Romero and Arias 1969, Patel et al. 2007, Haidar et al. 2008, Zakir and Bora 2009, Anwar and McKenry 2012). In India, Ditylenchus melongena, Helicotylenchus, Hoplolaimus, M. incognita, Pratylenchus, Radopholus, Rotylenchus, Rotylenchulus reniformis, Trichodorus and Tylenchorhynchus have been identified as pests of brinjal (Patel et al. 2007, Verma et al., 2013). In Pakistan, Helicotylenchus spp., M. incognita, M. javanica, Meloidogyne spp., Pratylenchus spp. and Xiphinema spp. have been recorded as major nematode pests of brinjal (Anwar and Chaudhry 1973, Shakeel et al. 2012). A study was conducted by Audamou et al. (2013) in Niger and identified Meloidogyne, Tylenchorhynchus, Helicotylenchus, Scutellonema, Rotylenchulus, Pratylenchus and Xiphinema as nematode pests of brinjal. From Syria, Haidar et al. (2008) reported ten plant parasitic nematodes of brinjal namely Meloidogyne, Pratylenchus, Paratylenchus, Tylenchus, Rotylenchus, Helicotylenchus, Tylenchorhynchus, Longidorus, Ditylenchus and Xiphinema. Available reports reveal that plant parasitic nematodes cause considerable damage to brinjal in India (Anowar et al. 1986, Patel et al. 2007, Verma et al. 2013), Pakistan (Shakeel et al. 2012), Niger (Audamou et al. 2013), Nigeria (Bhatti et al. 2013) and Spain (Romero and Arias 1969). Reports on nematode pests of brinjal are scanty in Bangladesh. Occurrence of only root-knot nematode (Meloidogyne spp.) has so far been recorded in the country (Timm and Ameen 1960, Mian 1986, Mian and Zahid 1986). More than 50 species of plant parasitic nematodes have been identified on different crop plants in Bangladesh (Sam 1979, Mian 1986, Rahman and Mian 2010). Reports so far discussed above indicate that the plant parasitic nematodes identified on various crops in Bangladesh may also attack brinjal. Under the above circumstances, a research project was undertaken to identify plant parasitic nematodes associated with soils and roots of brinjal in some intensively brinjal growing areas of Bangladesh.
MATERIALS AND METHODS
The survey was conducted in the districts of Kishoregonj, Mymensingh, Tangail, Manikgonj and Gazipur in Bangladesh during of 2011-2014. Brinjal is extensively grown in those areas. Rhizosphere soil and root samples of brinjal were collected from the fields of the selected districts from 20 places of each field at a depth of 15-20 cm. All 20 soil samples of each field was mixed together to have a composite sample. About 2.5 kg subsamples were drawn from each composite sample. Nematodes were extracted from soil and root samples following Baermann funnel method (Mian 1994). Temporary mounts of the extracted nematode were prepared and observed under a compound light microscope. Morphological characters and morpho-metrics of individual nematode specimens were recorded. For identification, related sets of CIH Descriptions of Plant-parasitic nematodes and other available key books, journal articles and internet descriptions as well as pictures were used. Female perineal pattern was studied to identify the species of root-knot nematodes (Taylor and Sasser 1980, Eisenback 2010).
RESULTS AND DISCUSSION
During the survey, a total of 12 nematode species under 11 genera were associated with rhizosphere soils and roots of brinjal. The nematode species were Aphelenchus aveneae, Cephalenchus emerginatus, Ditylenchus melongena, Helicotylenchus indicus, Hoplolaimus indicus, Meloidogyne incognita, Praty-lenchus pratensis, Pratylenchus zeae, Tylencho-rhynchus claytoni, Tylenchus sp., Xiphinema americanum and Zygotylenchus guevarai.
For identification of Aphelenchus aveneae, CIH Description of Plant-parasitic nematodes was consulted (Hooper 1974a). Female body is cylindrical with slight arcuate when killed by heat, maximum wide at vulval point, gradually tapering towards ends, posterior body behind vulva is nrrower than anterior region. Morphometrics of female are L = 120-127 µm, a = 30.4, b = 5.7, V = 70-75%. Stylet length is 13.5-15.5 µm. Head is bluntly rounded and not offset from the body. Vulva is a transverse slit. At mid-body lateral field is widest. Esophagus with cyndrical procorpus, median bulb well developed squarish, conspicuous, rectangular to oval shape having refractive cresentic valve plate. Ovary is monodelphic, prodelphic and outstretched. Esophageal lumen of dead nematode is strait and dorsal esophageal gland orifice is not visible because it opens in side the median bulb. Tail is 1.77 times of anal body diameter and tail tip is bluntly rounded (Plate I).
The nematode was identified based on characteristics described by Hooper (1974b). Body of adult female is relatively slender, small, only 500-580 µm long, vermiform, narrow only a little anterior but posterior to the bulb it tapers sharply forming a narrow long tail with a pointed terminus. Cuticle is fairly thick and annules slightly coarse. Cephalic framework mode rately set off and round. Lateral field has six lines. The stylet is relatively long compared to body length with rounded knobs. Stylet is well developed with round knobs. Esophagus is tylenchoid, basal bulb is not overlapping the intestine. Vulva is a transverse slit at 70-72% of body from the anterior end. Ovary is monodelphic prodelphic and outstretched (Plate II).
Helicotylenchus indicus (Spiral nematode)
The species of spiral nematode was identified consulting morphological and morphometrical characteristics described by Siddiqi (1972). Adult female body is vermiform with tapering towards both terminuses, length is 660-850 µm, a=28-33, b = 5.3-6.2. Posterior region of the female body forms a coil on thermal death. Annulations are distinct, not interrupted by lateral lines. Lateral fields are about one-sixth of body width, continuing to tail terminus, marked with four incisures. Lip region is hemispherical, cephalic framework is well developed, head slightly set off and conoid. Stylet is well developed, anteriorly tapering and knob is rounded. DGO is situated at less than half of stylet length behind the knob. Esophagus is tylenchoid with oval shape median bulb. Basal bulb overlaps anterior part of intestine from ventral side. Tail is, conoid with a narrow terminus and mucronate. Ovary is didelphic amphidelphic and outstretched. Vulva is transverse slit like at 65-70% of the body from anterior. Male is similar to female except less coiled body shape. Tail is elongate with mucron. Spicule is 20-25 µ (Plate III).
Ditylenchus melongena (Stem nematode)
The nematode genus was identified consulting the description of Hestling (1974) and Haider et al. (2008). Females are slender transparent, almost strait when relaxed or killed by heat. Labial framework is not well developed; lip region flattened and cap-like, not offset. Stylet is 111-13 μm long with distinct basal knobs. Lateral fields with four incisures. Tail terminus is sharply pointed. Measurements of female showed that L = 1020-1400 µm, a = 24.0, b = 5.2-39.5, V = 76 -87%. Dorsal esophageal grand orifice (DGO) is very close to stylet knob. Median bulb is fusiform. Basal bulb overlaps intestine mostly dorsally. Ovary is monodelphic and prodelphic. Tail shape is more or less conoid with pointed tip (Plate IV).
Tylenchorhynchus claytoni (Stunt nematode)
Descriptions of the species used for identification by Loof (1974b) were also used in the present investigation to identify the nematode. Adult female body is cylindrical, with weakly curve ventrally when relaxed. The body is more tapering towards posterior end. Body length is 680- 750 µm with coarse transverse striae. Lateral field consists of 4 longitudinal lines. Lip region of the nematode is rounded and offset by slight constriction. Stylet is slender with round basal knobs. Median bulb is oval; its valve located halfway along esophagus. Isthmus is long and narrow, terminal bulb pyriform, with conspicuous dorsal gland nucleus. Vagina is less than one-half body width long. Ovary is didelphic, amphi-delphic, outstretched. Rectum is about one-half o anal body width. Tail is tapering towards end (Plate V).
Hoplolaimus indicus (Lance nematode)
Hoplolaimus indicus was identified consulting the description of Khan and Chowla (1975). Adult female body is vermiform, cylindrical, tapering towards both ends, especially towards the anterior end and an open C-shaped after death due to heat. Female body length is 1020-1302 µm, ‘a’ and ‘b’ values are 23-28 and 7.1-8.2, respectively. Esophagus tylenchoid, stylet strong with backwardly projected knobs. Ovary is didelphic
and outstretched. Head is distinctly set off. Tail is shorter (22.1-22.4 µm) than anal body diameter (25.5-26.5 µm) with round tip. Anus is circular, 2.0-2.2 µm diameter, present on 18-20th annule from tail terminus. Annules on the tail terminus are anastomosed irregularly. Lateral field represented by two very indistinct striae, annulation continues round the body. Vulva is conspicuous, transverse slit, 10.0-12.0 µm wide with two distinct lips (Plate VI).
Root-knot nematode (Meloidogyne incognita).
The morphological and morphometrical characteristics of egg, larvae, the mature females, and perineal pattern of mature female were the basis of identification (Taylor and Sasser 1980, Barker et al. 1985, Eisenback 2010). Matured eggs are elliptical in shape containing J1 larvae (Plate VII A). Second stage larvae with prominent fat droplets, 210 to 3950 μm long, head region not offset. Stylet 15 to 25 μm in length, basal knobs set off, rounded to transversely elongated. Tail 25 to 65 μm in length, tip rounded and lateral lines four with incisures (Plate VII B). Third (J3) and fourth stage (J4) and immature females were found in the root galls of brinjal (Plate VII C). The perineal pattern is oval to rounded 90 to 100 μm in length and 82 to 100 μm in width. Generally high with dorsal arch. Anus anteriorly located 15 to 30 μm distance from vulval slit and anus located 14 to 20 μm distance from tail terminus. Lateral lines are not pronently demarcated by breaks and forked striae. Striae are distinct and wavy. Lateral fields weakly demarcated and not disrupted by the lateral lines. Tail terminus is smooth (Plate VII D).
Xiphinema americanum (Dagger nematode)
The genus was identified comparing the features described by Siddiqi (1973). Female body is vermiform, slightly tapering towards both ends, cuticle finely annulated. Adult female is 1400 to 2000 µm long. The most important identifying character is long stylet with flanges extension and more than 100 µm long. Lip region is hemispherical in shape and slightly expanded. Tail rounded with greater curvature dorsally and terminus conoid. It is needle like and about 72 µm long. Esophagus is divided into two parts having narrow corpus and cylindrical basal region. Vagina at right angles to body axis covering 40% of the body width. Vulva is situated at 50-54% of body length (Plate VIII).
Pratylenchus pratensis (Lesion nematode)
The species of lesion nematode was identified consulting the description of Loof (1974a). Female body is vermiform, more or less straight when killed by heat or on relax and 50-68 µm long; ‘a’ = 26-35, ‘b’ = 6.5-7. Stylet has three well separated knobs. DGO is present at less than one-third of stylet length behind the knobs. Esophageal lumen is not straight, median bulb is broadly oval in shape. Basal bulb overlaps the intestine ventratally. Excretory pore is located at anterior to the esophago-intestinal junction. Ovary is monodelphic prodelphic; uterus with large oval to rectangular spermatheca filled with sperm received from the male partner. The vulva is transverse and about 72-77% from the head. Post-uterine sac is slightly longer than body width. Tail with 25-28 annules and the terminus is slightly curve ventrally (Plate IX).
Pratylenchus zeae (Lesion nematode)
The nematode was identified consulting the description of Fortuner and Tom (1976). Female body is vermiform, almost straight on death by heat, marked by very faint annules and 450-475 µm long. Lateral field with 4 incisures. Lip region is not set off from the body. Tip of the head is bluntly round. Stylet is 16-17 µm long, basal knob anteriorly flattened. DGO locate 3 µm behind stylet base. Basal bulb of esophagus is overlaps intestine ventrally. Ovary single and prodelphic. Post-uterine sac is short, 2 body width long. Vulva is at 70-76%. Tail tapering, terminus is almost pointed and narrowly sub-acute (Plate IX).
The genus was identified comparing the characters described by Siddiqi (1974). Female is vermiform, slightly tapering towards both extremities, slightly arcuate ventrally when relaxed due to thermal death. Cuticle with distinct annulations, lateral field with 4 incisures, without arealation. Esophagus is tylenchoid, basal bulb elongate, lobed, and extending over intestine ventrally and laterally. Style is strong with round basal knobs. Cephalic frame-work is sclerotized, round, low, anteriorly flattened, conoid, labial disc squire. Tail elongate, cylindrical, terminus broadly rounded. Ovary two, vulva sub median, characterized by a transverse slit with slightly raised lips (Plate X).
Tylenchus was identified using description of Andrassy (1977). It is a small nematode body length less than 1.0 mm. Tail is elongate conoid to filiform. Stylet with distinct knobs. Median bulb is prominent with vulvular apparatus. Basal bulb is abutting with cardia over the intestine. Ovary is monodelphic prodelphic. Vulva lip is raised and well posterior to middle of body. Tail filiform with pointed terminus (Plate IX).
Results of the present survey reveal that at least 12 species of plant parasitic nematodes are associated with soils and roots of brinjal may attack brinjal in Bangladesh. Most of them have also been reported from India (Anwar et al. 1986, Patel et al. 2007, Vermam et al. 2013), Pakistan (Bhatnagar et al. 1969, Anwar and Choudhry 1973, Maqbool 1986, Shakeel et al. 2012) and other countries (Romero and Arias 1969, Audamou et al. 2013, Bhatti et al. 2013) as pests of brinjal. Available reports from Bangladesh reveal that all of the genera of nematodes were found to be associated with soils and roots have been reported on other crops of the country (Timm and Ameen 1960, Mian 1986, Mian and Zahid 1986, Mian 1987, Mian and Tsuno 1988). Except root-knot nematode, existence of other 11 plant parasitic nematodes of brinjal has not yet been reported earlier from Bangladesh. So, these may be reported from the country for the first time.
Andrassy, I. 1977. Tylenchus sp. CIH Descriptions of Plant Parasitic Nematodes set 7 No. 97.
Anonymous. 2004a. Hand book of agricultural technology. Bangladesh Agricultural Research Institute (BARI), Joydebpur, Gazipur-1701. pp. 330-33.
Anwar, S. A. and Chaudhry, G. Q. 1973. Nematodes associated with egg plant (Solanum melongena) roots. J. Agriil. Res. Punjab. 11(4):93. In Helminthological Abstract – Series B. 1977. Vol. 66 No. 3.
Anwar, S. A. Kalu, M. A., Javid, M. A. and Khan, S. H. 1986. Nematode parasites of brinjal. A. Agric. Res. 24:124-126.
Anwar, S. A. and McKenry, M. V. 2012. Incidence and population density of plant-parasitic nematodes infecting vegetable crops and associated yield losses in Punjab, Pakistan. Pakistan J. Zool. 44(2): 327-333.
Audamou, H., Audamou, B., Oumarou, A. H., Seyni, S. R., D., and Toudou. 2013. Characterization of plant parasitic nematode communities associated with tomato, eggplant and pepper in the suburban area of Niamey (Niger). Intl. Agri. Crop Sci. 5(20): 2488-2494.
Barker, K. R., Carter, C. C. and Sasser, J. N. 1985. An advanced treatise on Meloidogyne. Volume II. North Carolina State University Graphics, Raleigh, North Carolina: Methodology. A cooperative publication of the Department of Plant Pathology and the United States Agency for International Development. 1985. pp. 69–77.
Bhatti, K. H., Kausar, N., Rashid, U., Hussain, K., Nawaz, K. and Siddiqi, E. H. 2013. Effects of biotic stresses on eggplant (Solanum melongena L.). World Appl. Sci. J. 26 (3): 302-311.
Bhatnagar, R.D.S. and Kadyan, A.S. 1969. A preliminary survey of the plant-parasitic nematodes of brinjal from the Punjab. J. Res. – Punjab Agri. Univ. (1):281-289.
Eisenback, J. D. 2010. A New Technique for Photographing Perineal Patterns of Root-knot Nematodes. J. Nematol. 42(1): 33–34. PMCID: PMC3380516.
Fortuner, R.1976. Pratylenchus zeae. CIH Descriptions of Plant Parasitic Nematodes. Set 6 No.77.
Haidar, A., Al-Assas, K. and Al-Ashkar, K. 2008. Survey of phytoparasitic nematode and vesicular arbuscular mycorrhizal fungi genera associating eggplant in Reef Damascus governorate, Syria. Arab Journal of Plant Protection. 26(2):123-128.
Hestling, J. J. (1974). Ditylenchus myceliophagus. CIH Descriptions of Plant-parasitic Nematodes. Set 3 No 36.
Hooper, D. J. 1974a. Aphalenchus avenae. CIH Descriptions of Plant Parasitic Nematodes. Set 4 No.50.
Hooper, D. J. 1974b. Cephalenchus emarginatus. CIH Descriptions of Plant Parasitic Nematodes. Set 3 No.35.
Khan, E. and Chawla, M. I. 1975. Hoplplaimus indicus. Plant Parasitic Nematodes. Set 35 No.68.
Loof, P. A. A. 1974. Tylenchorynchus claytoni. Plant Parasitic Nematodes.set3 No.39.
Loof, P. A. A. 1974a. Pratylenchus pratensis. CIH Descriptions of Plant Parasitic Nematodes. Set 4 No.52.
Loof, P. A. A. 1974b. Tylenchorynchus claytoni. Plant Parasitic Nematodes. Set 3 No.39
Maqbool, M.A. 1986. Classification and distribution of plant nematodes in Pakistan. Natl. Nematol. Res. Cen., Uni. Pak., Karachi, Pakistan.
Mian, I. H. 1986. Plant parasitic nematodes associated with some crop species of Bangladesh. Bangladesh J. Plant Pathol. 2(1&2):7-13.
Mian, I. H. 1987. Survey of potato nematodes in Bangladesh. Bangladesh Hort. 15(1):17‑22.
Mian, I. H. and Zahid, M. I. 1986. Plant parasitic nematodes associated with betelleaf in Bangladesh. Bangladesh Hort. 14 (2): 49‑51.
Mian, I. H. and Tsuno, K. 1988. Identification of major species of Meloidogyne and location of their females in root galls using scanning electron microscope. Bull. Inst. Trop.Agr., Kyushu Univ. 11: 15‑22.
Mian, I. H. 1994. Introduction to Nematology. Publication No. 23, IPSA-JICA Project. BSMRAU, Gazipur-1706. pp. 64-86.
Patel, A. D., Panickar, B. K., Patel, B. A., and Patel, D. J. 2007. Community analysis of plant parasitic nematodes associated with agricultural crops in Junagadh district of Gujarat and Diu-union territory. Indian J. Nematol. 37(1): 68-71.
Rahman, M. M. and I. H. Mian. 2010. Isolation, and identification of ten genera of plant parasitic nematodes. Bangladesh J. Sci. Ind. Res. 45(3): 267-270.
Romero, M. D., Arias, M. 1969. Nematodes of solanaceous plants cultivated in the southern Spanish Mediterranean area. I. Tylenchida. [Boletin de la Real Sociedad Espanola de Hostoria Natural (1969) Vol. 67 pp. 121-142]. In: Helminthological Abstracts-Series B, 1977, Vol. 46 No. 1. Abstract No. 27.
Sam, L. P. 1979. An assessment of the importance of and control of plant parasitic nematodes of vegetables in Bangladesh. Imperial College, Field statin, Silwood Park, Berkshire, England, 36 pp.
Shakeel, Q., Javed, N., Iftikhar, Y., Haq, I. U., Khan, S. A. and Ullah, Z. 2012. Association of plant parasitic nematodes with four vegetable crops. Pak. J. Phytopathol. 24(2):143-148.
Siddiqi, M. R. 1972. Helicotylenchus indicus. CIH Descriptions of Plant Parasitic Nematodes. Set 5 No.68
Siddiqi, M. R. 1973a. Xiphinema americanum. CIH Descriptions of Plant Parasitic Nematodes. Set 2: No.29
Siddiqi, M. R. 1975. Zygotylenchus guebarai. CIH Descriptions of Plant Parasitic Nematodes. Set 5 No.65
Taylor, A. L. and Sasser, J. N. 1980. Biology, identification and control of root-kot nematode (Melooidogyne species). International Meloidogyne project. A cooperatibe publication of the Department of Plant Pathology, North Carolina State University and United State Agency for International Development. North Carolina State University, Raleigh, NC 27607, USA. 111 pp.
Timm, R. W. and Ameen, M. 1960. Nematode associated with commercial crops of East Pakinstan. Agric. Pak. 11:355-363.
Verma, D., Kumar, M. and Nazeri, M. 2013. Collection and population frequency of phyto-parasitic nematodes associated with brinjal (solanum melongena) in North Uttar Pradesh region: A field study. J. Cur.Res. Sci. 1(3):169-172. Available at www.jcrs010.com
Zakir, H. and Bora, B. C. 2009. Interrelationship of Meloidogyne incognita and Ralstonia solana-cearum complex in brinjal. Indian J. Nematol. 39(1): 41-45.