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Anatomical Parameters of Cowpea, Vigna Unguiculata (L.) Walp. Stem and Pod Wall Resistance to the Legume Pod Borer Maruca testulalis Geyer (Lepidoptera: Pyralidae)

Published online by Cambridge University Press:  19 September 2011

S. Oghiakhe
Affiliation:
International Institute of Tropical Agriculture (IITA), PMB 5320, Oyo Road, Ibadan, Nigeria
L. E. N. Jackai
Affiliation:
International Institute of Tropical Agriculture (IITA), PMB 5320, Oyo Road, Ibadan, Nigeria
W. A. Makanjuola
Affiliation:
Department of Biological Sciences, University of Lagos, Akoka, Yaba, Lagos, Nigeria
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Abstract

Anatomical features of cowpea (Vigna unguiculata) associated with stem and pod wall resistance to the legume pod borer, Manica testulalis, were studied. The anatomical microenvironment of the area immediately post the stem epidermis seems to impose severe limitation to larval movement and feeding within the tissue. Collenchyma cells in both 21-day old TVu 946 and IT82D-716 stems form a network of closely knit interlocking cells with a few intercellular spaces. Significant differences (P < 0.05) were observed in the distance between the epidermis and collenchyma cells of the slightly raised (convex) and concave portions of TVu 946 and IT82D-716 stems. TVu 946 had a smaller stem diameter than IT82D-716 stem. Distance between epicarp and mesocarp tissues of 7-day old TVu 946 and IT82D-716 pod wall did not show any significant difference. Similarity in cell and tissue arrangement and the absence of strengthening tissues in pod wall could be some of the most important constraints responsible for their vulnerability to larval damage.

Stem anatomy is considered to be an important factor in stem resistance to M. testulalis, but this does not appear to be the case in pod wall resistance.

Résumé

Les caractèristiques anatomiques du nièbé (Vigna unguiculata) associées à la résistance de la tige et de la gousse aux foreuses Maruca testulalis ont été étudiées. Le microenvironnement anatomique de la partie qui vient immédiatement après l'épiderme de la tige semble entraver sérieusement tout mouvement et alimentation larvaires dans les tissus. Les cellules collenchymateuses des tiges de TVu 946 et IT82D-716, âgées de 21 jours, forment un dense réseau de cellules enchevêtrées au sein duquel l'on trouve quelques espaces intercellulaires. Des différences significatives (P < 0.05) ont été observées dans la zone située entre l'épiderme et les cellules collenchymateuses des portions de tige lélérement bombées (convexes) et concaves de TVu 946 et IT82D-716. TVu 946 avait une tige de diamètre inférieur à celui de la tige d'IT82D-716. La partie située entre les tissus de l'épicarpe et du mésocarpe des gousses de TVu 946 et IT82D-716, âgées de 7 jours, n'a pas laissé paraître de différence significative entre les deux variétés. Une certaine similarité dans l'arrangement des cellules et des tissus ainsi que l'absence de tissus de renfort dans la paroi des gousses seraient la principale cause de leur vulnérabilité aux dégâts des larves.

L'anatomie de la tige est considérée comme un facteur important pour la résistance de la tige à M. testulalis; toutefois, il semblerait que cela ne s'applique pas à la résistance des gousses.

Type
Articles
Copyright
Copyright © ICIPE 1991

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References

REFERENCES

Agarwal, R. A. (1969) Morphological characteristics of sugar-cane and insect resistance. Entomol. Exp. Appl. 12, 767776.CrossRefGoogle Scholar
Chiang, H. S. and Norris, D. M. (1983) Physiological and anatomical stem parameters of soybean resistance to agromyzid beanflies. Ent. Exp. Appl. 33, 203212.CrossRefGoogle Scholar
Esau, K. (1977) Anatomy of Seed Plants. John Wiley and Sons, Inc., New York.Google Scholar
Howe, W. L. (1949) Factors affecting the resistance of certain cucurbits to the squash borer. J. econ. Entomol. 42, 321326.CrossRefGoogle Scholar
IITA (1986) Grain Legume Improvement Program Annual Report 1985. Ibadan, Nigeria.Google Scholar
Jackai, L. E. N. (1981) Relationship between cowpea crop phenology and field infestation by the legume pod borer, Maruca testulalis. Ann. Entomol. Soc. Am. 74, 402408.CrossRefGoogle Scholar
Jackai, L. E. N. (1982) A field screening technique for resistance of cowpea (Vigna unguiculata) to the pod borer Maruca testulalis (Geyer) (Lepidoptera: Pyralidae). Bull. Entomol. Res. 72, 145156.CrossRefGoogle Scholar
Jackai, L. E. N. and Oghiakhe, S. (1989) Pod wall trichomes and resistance of two wild cowpea, Vigna vexillata, accessions to Maruca testulalis (Geyer) (Lepidoptera: Pyralidae) and Clavigralla tomentosicollis Stal (Hemiptera: Coreidae). Bull. Entomol. Res. 79, 595605.CrossRefGoogle Scholar
Ledbetter, M. C. and Porter, K. R. (1970) Introduction to the Fine Structure of Plant Cells. Springer -Verlag BerlinHeidelberg.CrossRefGoogle Scholar
Macfoy, C. A. and Dabrowski, Z. T. (1984) Preliminary studies on cowpea resistance to Aphis craccivora Koch. (Hom., Aphididae). Z. Angew. Entomol. 97, 202209.CrossRefGoogle Scholar
Martin, G. A., Richard, C. A. and Hensley, S. D. (1975) Host resistance to Diatraea saccharalis (F.): Relationship of sugar-cane internode hardness to larval damage. Environ. Entomol. 4, 687688.CrossRefGoogle Scholar
Norris, D. M. and Kogan, M. (1980) Biochemical and morphological bases of resistance. In Breeding Plants Resistant to Insects (Edited by Maxwell, F. G. and Jennings, P. R.) John Wiley & Sons, New York.Google Scholar
Salifu, A. B., Hodgson, C. J. and Singh, S. R. (1988) Mechanism of resistance in cowpea (Vigna unguiculata (L.) Walp.) genotype, TVx 3236 to the bean flower thrips, Megalurothrips sjostedti (Trybom) (Thysanoptera: Thripidae). 2. Nonpreference and antibiosis. Trop. Pest Manage. 34, 180184.Google Scholar
Singh, S. R. (1978) Resistance to pests of cowpea in Nigeria. In Pests of Grain Legumes: Ecology and Control (Edited by Singh, S. R., van Emden, H. F. and Taylor, T. A.), pp. 267279. Academic Press Inc., New York.Google Scholar
Singh, S. R. (1980) Biology of cowpea pests and potential for host plant resistance. In Biology and Breeding for Resistance to Arthropod and Pathogens in Agricultural Plants (Edited by Harris, M. K.). College Station, Texas A & M University Bulletin MP 1451.Google Scholar
Wallace, L. E., McNeal, F. H. and Berg, M. A. (1973) Minimum stem solidness required in wheat for resistance to the wheat stem sawfly. J. econ. Entomol. 66, 11211123.CrossRefGoogle Scholar