Root-lesion nematodes of the genus
Pratylenchus are recognised worldwide as one of the major constraints of crops of primary economic importance.
Pratylenchus spp. comprises around 70 nominal species of worldwide distribution which parasitize a wide variety of plants. The book consists of ten chapters and presents summarised and specialised information concerning the importance of the
Pratylenchus species in: agricultural crops, and their world distribution (chapter 1); taxonomy, systematic, general morphology and diagnostic traits of
Pratylenchus spp. including new technologies based on biochemical and molecular analyses (chapters 2-6); biology, epidemiology, ecology, host-parasite relationships, and pathogenicity (chapters 7-9). Finally, it illustrates different management strategies for
Pratylenchus species, including, crop rotation, host-plant resistance, chemical control, soil solarisation, and biological control (chapter 10).
The volume deals with morphology, taxonomy and systematics of entomopathogenic nematodes (EPN) in the families Steinernematidae and Heterorhabditidae and bacteria associated with these nematodes.
In the first part, history, taxonomic status, family and genus definitions of EPN are mentioned. In the second part, all useful aspects of morphology and methodology of EPN are mentioned with illustrations and SEM photographs and instructions on how to make the measurements, and how to use them in taxonomic work. A polychotomous key with SEM photographs and illustrations is provided. In the third part, full descriptions of all species are presented with latest information about each species. In the fourth part, molecular and phylogenetic methods for working with EPN are presented, including the latest information and instructions on how to use molecular data in taxonomic work. In the last part, bacteria associated with this group of nematodes are discussed in the context of the latest information about methodology, biology and taxon.
This is the first and so far the one and only treatise on the morphology of the Tylenchs. Tylenchs are economically important Nematodes that live in huge numbers in the soil. They are microscopic and they show a constant number of cells, a characteristic in Nematodes. The cell count in Tylenchs, undertaken here for the first time, resulted in an estimate of fewer than a thousand cells. All the different cell types are described in great detail, and some of them are rather unusual in the Animal Kingdom. The internal pressure system (typical for Nematodes) in conjunction with the presence of a hollow stylet (typical for Tylenchs), results in rigorous but functional relations among the several body parts. Throughout the book functional morphology is a key topic and an entire chapter is devoted to it. The book is amply illustrated with line drawings that are based on microscopic and sub-microscopic observations.
The spiral plant-parasitic nematode genus
Rotylenchus contains a cosmopolitan group of nematodes that is predominantly found in temperate regions of the world. In this genus are included a number of species of significant economic importance in agriculture. They parasitize a wide-range of hosts, including vegetables, ornamentals, and fruit and forest trees.
The book comprises seven sections and presents summarised and specialised information on various aspects of the spiral nematodes belonging to the genus Rotylenchus. Sections 1 and 2 describe the importance of Rotylenchus species in agricultural crops, their distribution and numerous aspects of their biology, feeding habits, pathogenicity to vegetables, fruit and forest trees, and ecology. Section 3 presents different management strategies for the most important and pathogenic species of Rotylenchus, including chemical control, crop rotation, and biological control by means of nematophagous fungi, entomopathogenic nematodes, the hyperparasitic bacteria Pasteuria penetrans, and nematicidal plants. Sections 4 and 5 describes the most important morphological characters used in characterising and diagnosing species, as well as a broad discussion on the taxonomy and systematics in Rotylenchus and related genera, including a list of nominal species. These sections also include morphometric and cluster analyses in order to separate groups of species in order to facilitate identification. Section 6 provides a complete description and measurements of all populations characterised for each species, as well as their world distribution. Finally, Section 7 includes comprehensive tabular and dichotomous keys for species identification.
According to the European Plant Protection Organization, the pinewood nematode (PWN), Bursaphelenchus xylophilus is a quarantine organism at the top of the list of the pathogenic species. PWN may be found in North America (Canada, USA and Mexico) and in East Asia (Japan, Korea, China and Taiwan) and has a highly destructive capability towards conifers, in a relatively short time, causing serious economic damage in Japan, China and Korea. This nematode surveying is extremely important and a correct identification of nematode species associated with conifers is essential. Several conifers species are very susceptible (Pinus sylvestris, Pinus nigra and Pinus pinaster), the last one (maritime pine) is a particulary important economic specie in Portugal, and in southern Europe.
In 1999, this nematode was found and identified for the first time in Portugal and in Europe. During 1999 and 2000, the Portuguese government, following an alert provided to European Community officials initiated an extensive national survey. During 2000 and 2001, research has been carried out regarding the morphobiometric as well as molecular (DNA: ITS-RFLP) characterization of the collected populations, as well as closely related species of Bursaphelenchus.
The book details the Proceedings of an international workshop held at the University of Évora in 2001, covering all major aspects of the bioecology of the pinewood nematode (PWN), Bursaphelenchus xylophilus, its insect vectors and effects on the tree.
Topics covered are: global issues and national surveys; morphology and molecular methods of identification of PWN; ecology and epidemiology; quarantine issues; tree physiology, resistance and histopathology; biology of PWN and relationships to its cerambycid vectors; control methods. General quarantine and political views are also presented.