Heterodera latipons

About: Heterodera latipons is a research topic. Over the lifetime, 47 publications have been published within this topic receiving 1634 citations.

First Report of the Cereal Cyst Nematode Heterodera latipons on Wheat in Morocco

Abstract: From May to June 2011, during a survey of the wheat-growing areas in Meknes in the Sais Region of Morocco, several cyst nematode populations were detected. Sampling was performed 1 month before wheat (Triticum durum) harvest, in fields showing patches of stunted plants. Plants were growing poorly, had chlorotic lower leaves, and a reduced numbers of ears. Root systems were short and had a bushy appearance because of increased secondary root production. No cysts were visible on the roots, but were found in the soil. Cysts were collected from soil on 200-μm sieves by the modified Cobb decanting and sieving method (1) and identified by morphology and internal transcribed spacer (ITS)-rDNA sequencing. All isolates were identified as Heterodera avenae except the isolate from Ain Jemâa. From the latter, key morphological features from cysts and second-stage juveniles (J2) were determined. The cysts (n = 10) had the following characteristics: bifenestrate vulval cone, body length without neck 590 μm (551 to 632 μm), body width 393 μm (310 to 490 μm), neck length 75 μm (65 to 90 μm), fenestra length 64 μm (60 to 72 μm) and width 21 μm (18 to 25 μm), underbridge length 96 μm (85 to 115 μm), vulval slit length 8 μm (7 to 9 μm), vulva bridge width 27 μm (24 to 33 μm), and bullae absent. The J2s (n = 10) had the following characteristics: body length 445 μm (412 to 472 μm), body width 19 μm (19 to 21 μm), stylet length 24 μm (23 to 25 μm), four lateral lines, tail length 50 μm (46 to 54 μm), and hyaline terminal tail 28 μm (24 to 31 μm). Values of the morphological characters were within the range of H. latipons reported by Handoo (3). The bifenestrate cysts with a strong underbridge and no bullae and J2 with a tail length greater than 40 μm, a stylet longer than 15 μm, and four incisures in the lateral field were typical for H. latipons. To confirm the identification, molecular observations were made. DNA was extracted from three juveniles from three different cysts separately (4). The ITS-rDNA region was amplified using the primers 5'-CGT AAC AAG GTA GCT GTA G-3' and 5'-TCC TCC GCT AAA TGA TAT G-3' as described by Ferris et al. (2). This resulted in a 1,040-bp DNA fragment. The PCR-products were purified and sequenced (Macrogen, Inc., Seoul, Korea). All sequences obtained (GenBank Accession Nos. per cyst: JQ319035, JQ319036, and JQ319037) were compared with sequences available from the GenBank database ( www.ncbi.nlm.nih.gov ), including several species of Heterodera. This comparison revealed a sequence similarity of 97 to 99% with H. latipons and 89% or lower with any other species of Heterodera. Morphological and molecular identification demonstrated that the population of cyst nematodes from a wheat field in Ain Jemâa, Morocco was H. latipons. In the patches with poor growing plants, 65 cysts per 100 cm3 soil were found. To our knowledge, this detection represents a new record of H. latipons. Since the nematode can cause considerable damage to wheat, one of the main cereals produced in Morocco, care should be taken to prevent the spread to other regions. References: (1) K. R. Barker. Page 19 in: An Advanced Treatise on Meloidogyne. Vol II. Methodology. C. C. Carter and J. N. Sasser, eds. North Carolina State University Graphics, Raleigh, 1985. (2) V. R. Ferris et al. Fundam. Appl. Nematol. 16:177, 1993. (3) Z. A. Handoo. J. Nematol. 34:250, 2002. (4) M. Holterman et al. Mol. Biol. Evol. 23:1792, 2006.

Induced Resistance to Cyst and Root-knot Nematodes in Cereals by DL-β-amino-n-butyric Acid

Abstract: Foliar sprays and soil drenches with DL-β-amino-n-butyric acid (BABA) reduced the number of Heterodera avenae and H. latipons cysts on wheat and barley. Foliar sprays of wheat with 8000 mg l−1 BABA reduced the number of H. avenae cysts by 90%, whereas 2000 mg l−1 BABA was enough to reduce the number of H. latipons cysts by 79%. Multiple spray treatments with 2000 mg l−1 BABA at 10-day intervals reduced the number of H. avenae cysts on wheat and barley. A soil drench of wheat with 125 mg l−1 BABA reduced the number of H. latipons cysts by 93% and H. avenae cysts by 43%. Second-stage juveniles of these nematodes penetrated and formed syncytia in wheat roots soil-drenched with BABA. More adult males of H. avenae were produced in BABA (<250 mg 1−1)-treated wheat roots (~76%) than in untreated roots (27%). Soil drenches with higher concentrations of BABA inhibited development of adult males and females. Several chemical elicitors of induced resistance were tested for their ability to reduce the number of H. avenae cysts on wheat. Only BABA was found to be an effective resistance inducer. The number of egg masses of an unidentified Meloidogyne sp. root-knot nematode, which infects only monocots, was also reduced by 95% by a soil drench of wheat with 500 mg l−1 BABA. Development of this nematode inside the BABA-treated roots was also inhibited.

Genetic and phenotypic diversity in the graminaceous cyst nematode complex, inferred from PCR-RFLP of ribosomal DNA and morphometric analysis

Abstract: Graminaceous cyst nematodes form a group of eleven valid species including Heterodera avenae, Heterodera filipjevi and Heterodera latipons and constitute major pests to cereals They are widely spread in circum-mediterranean areas where they are presumed to cause yield losses on bread and durum wheat The objective was to document the diversity of these cereal cyst nematodes, in particular samples from Mediterranean regions, in comparison to species which develop on cultivated or wild grasses (H arenaria, H hordecalis, H mani) and on rice or sugarcane (H sacchari) Studies involved PCR-RFLP of ITS and morphometrics of the juvenile and cyst characters UPGMA analysis of molecular data showed that the isolates segregated in two main clusters which seem to represent different evolutionary lineages The H avenae sensu lato cluster (I) contained H arenaria, H avenae, H filipjevi and H mani The second cluster (II) contained isolates of H hordecalis and H latipons Within H avenae sensu lato, H filipjevi was separated from the other related species with significant bootstrap value The differentiation of H arenaria, recognized for the first time based on molecular data, and H mani with few restriction enzymes were the least significant Intraspecific polymorphism allowed differentiation of isolates originating from Australia within H avenae sensu stricto The group H hordecalis–H latipons showed the greatest genetic variability between and within isolates Two representatives of Heterodera sacchari, taxonomically included in the ‘schachtii’ group, were genetically as distant to this group as to the other graminaceous species belonging to either H avenae sensu lato or H hordecalis–H latipons group Results inferred from multivariate analysis applied on morphometrics of the cysts and juveniles showed agreement between genetic and phenotypic classifications This study demonstrates the utility of combined molecular and classical methods to enhance our knowledge about the diversity within the complex of graminaceous cyst nematodes and to establish robust techniques to identify a wider set of nematode species

Heterodera Latipons N. Sp., a Cereal Cyst Nematode From the Mediterranean Region

Abstract: Heterodera latipons n. sp., which was found on the roots of wheat and barley in Israel and Tripoli, can also infest oats and rye. The cysts resemble those of H. turcomanica Kirjanova & Shagalina, 1965, but lack the gland-like structures on the cyst wall and the eggs are larger, 112 X 48 μ, instead of 77 × 40 μ. Eggs and larvae are smaller than those of H. avenae and the fenestration of the cyst cone is different.

Variation in virulence of cereal cyst nematode populations from North Africa and Asia

Abstract: Eight populations of Heterodera avenae, H. filipjevi and H. latipons were tested in Petri dishes with six cereal differentials of the International Test Assortment and a set of resistant genotypes of wheats. Ratios of white females/juveniles inoculated were equivalent to those obtained previously in tubes and pots and confirmed the validity of the miniaturised technique used to study the virulence/resistance relationships of these nematodes and cereals. The populations were differentiated by virulence to barley differentials and a new group of pathotypes of H. avenae originating from Algeria was established. Differentiation among H. avenae populations from North Africa and West Asia was clearly demonstrated by their (a)virulence to the gene Cre1 in Triticum aestivum cv. Loros. As previously observed, cultivated and wild oats were poor hosts for Mediterranean populations of H. avenae, but contrasting host responses were observed for a physiological winter type of oat. In addition to describing the virulence status of H. filipjevi and H. latipons populations to barley, oat and wheat differentials, these results provide information for the introduction of resistance to barley and wheat breeding programmes.