Disease and Insect Resistance in Plants

Abstract

Disease and Insect Resistance in Plants provides a rich overview of host plant resistance and its application to crop and pest systems. It emphasizes conventional approaches, but it also covers modern techniques in assessing plant resistance, including cell and tissue culture andmolecular genetics (mainly inChapter 7). The book has a strong conceptual base that presents an excellent review of classical theories of hostÐ parasite interaction, the gene-for-gene hypothesis, and vertical and horizontal resistance. Disease and Insect Resistance in Plants is also practical in its discussion of laboratory and Þeld methods for identifying and developing resistant crop plants and in its attention to evaluation and eventual deployment of resistant plants. Thebookdraws concepts and examples fromawide range of crops and pests, but it focuses on certain Þeld and vegetable crops, particularly rice, wheat, oat, potato, and tomato. Consequently, crop pests and pathogens such as brown planthopper, Hessian sy, greenbug, rusts, late blight, and powdery mildew often receive detailed discussion spanning several paragraphs or a few pages at a time. These examples recur frequently throughout the book. Treatment of other cropÐpest examples is brief, sometimes limited to a single sentence. Disease and Insect Resistance in Plants is one of a few textbooks that covers resistance to both diseases and invertebrate pests. Several chapters effectively blend discussion of disease and invertebrate examples, especially in relation to the value of resistance (Chapter 1), resistance sources and testing methods (Chapter 5), conventional breeding methods (Chapter 6), and the stability and vulnerability of resistance (Chapter 8). However, discussion of disease versus invertebrate resistance is unevenly partitioned in other parts of the book. Chapters 2 (disease concepts) and 4 (genetics of hostÐparasite interaction) collectively devote 126 pages to discussion of disease resistance in plants, whereas Chapter 3 allots roughly 45 pages to plant resistance against arthropods and compiles examples of resistance to nematodes 5 pages that make up Table 3.12. Chapter 7 (unconventional breeding methods) devotes 11 pages to plant pathogens, but only 2 pages to nematodes and 1 page to arthropods. In separating discussion of disease versus invertebrate resistance,Disease and Insect Resistance in Plants fails to link common threads of these subjects. For example, the gene-for-gene concept, originally developed to describe the relationship between virulence genes of fungal pathogens and disease-resistance genes in plants, has proven applicable in explaining interactions of host plants with other pathogens and with arthropod and nematode pests. The book could have pointed out that this concept applies to pathogen races and toarthropodbiotypes.Forexample,Chapter 3 covers plant resistance in relation to virulence of arthropod biotypes, and Chapter 4 covers the genefor-gene concept in the traditional manner with regard to virulence of plant pathogens. Unfortunately, the gene-for-gene concept is notmentioned explicitly in Chapter 3, except for a brief remark of studies that discount a “gene-for-gene relationship” between rice and the brown planthopper. Additionally, strict adherence tonarrowinterpretationsof thegene-for-geneconcept and its corollaries leave the reader with limited guidance on application of these principles to pathogens such as viroids or to plant defense systems based on structuralmodiÞcationssuchas leaf trichomes inrelation to arthropod resistance. The book also missed a clear opportunity to discuss plant pathogenÐvectorÐhost interactions in relation to resistance breeding, and the strategies of developing resistance to vectors versus the pathogens they transmit.More discussion and examples ofmanaging pathogenÐvector systems by host plant resistance (e.g., resistance in wheat to the wheat curl mite for limiting Wheat streak mosaic virus) would have enhanced the book. The abundant examples presented in Disease and Insect Resistance in Plants are supported by extensive references with a bibliography making up more than one sixth of the book. The authors fulÞll their objective to revise and enlarge their 1986 book entitled Breeding for Resistance to Diseases and Insect Pests by emphasizing newer and recent techniques and by citing 500 new references. Nevertheless, older references and examples are retained; thus, the book supplies both classic and modern examples of resistance topathogensandpests.Unfortunately, newreferences are not evenly distributed, but rather clustered among subject areas, as with Chapter 7Os 88 post-1986 references. Despite these updates, this chapter still cites some references from the 1970s or early 1980s as “recent” examples. Sometimes new references are compiled in lengthy tables rather than being integrated into text, e.g., Table 3.12 and especially Table 4.1, which spans 40 pages in updating the inheritance of resistance to pathogens in various plant species since 1990. Some chapters (e.g., Chapter 6) contain sections devoid of updated references. The book generally reads well, but editorial deÞciencies are apparent. The text contains many punctuation errors and misspellings. Intermittent use of oneor two-sentence paragraphs produces staccato text and a catalog-like list of examples of pathogen and invertebrate pests. Some lengthy paragraphs lack topic sentences, and there is occasionally poor transition between paragraphs. Sections and especially chapters have abrupt endings that lack bridging to material that follows. Text could have been tightened to improve readability. The font is small and straining to read. Many areas would have beneÞted from pictures, drawings, or other illustrations.