Contents - Faperta

Physico-Chemical and Molecular Markers for Resistance to Insect Pests 157
TABLE 6.1
Morphological Markers Associated with Resistance to Heliothis/Helicoverpa
Crop Morphological Trait Remarks References
Cotton Nectarless Nonpreference Lukefahr et al. (1960)
Leaf pubescence Oviposition
preference
Butter et al. (1996)
Low bract teeth Resistance Rao et al. (1996)
Red leaf Resistance Ansingkar et al. (1984)
Okra leaf Resistance Wu, Cai, and Zhang (1997)
Frego-bract Resistance Wu, Cai, and Zhang (1997)
Erect growth habit Resistance Navasero and Ramaswamy (1991)
Glandless Susceptibility Narayanan and Singh (1994)
Tough bolls Resistance Mohan et al. (1995)
Pigeonpea Nonglandular trichomes Resistance Romeis, Shanower, and Peter (1999)
Colored seeds Resistance Nanda, Sasmal, and Mohanty (1996)
Long and wide pods Susceptibility Nanda, Sasmal, and Mohanty (1996)
Clustered podding Susceptibility Raut et al. (1993)
Indeterminate growth habit Resistance Lateef and Pimbert (1990)
Chickpea Glandular trichomes Resistance Yoshida, Cowgill, and Wightman
(1997)
Long and wide pods Susceptibility Gururaj et al. (1993)
Tomato Glandular trichomes Resistance Farrar and Kennedy (1988),
Sivaprakasam (1996)
Pubescence Oviposition
preference
AVRDC (1987)
Calyx texture and fl owering Resistance Cosenza and Green (1979)
Fruit skin Resistance Cosenza and Green (1979)
Bigger vine size Resistance Ferry and Cuthbert (1973)
Soybean Trichomes Resistance Panda (1979)
Visual Stimuli
Insects use vision to recognize the shape of, and chemical stimuli to perceive, the host
plant. Host fi nding from a distance is the fi rst step in host plant selection and colonization
by insects. It involves the visual stimuli emitted by the host plant, for example, aphids are
attracted to yellow-white surfaces (Moericke, 1969; Prokopy and Owens, 1983), cotton white
fl y, Bemisia tabaci (Genn.) is attracted to yellow-green and yellow-red (Hussain and Trehan,
1940), and sorghum midge, Stenodiplosis sorghicola (Coquillett) to white-yellow colors
(Sharma, Leuschner, and Vidyasagar, 1990; Sharma and Franzmann, 2002). Grasshoppers
orient themselves towards vertical lines or objects (Williams, 1954). The glossy trait of
cabbage, Brassica oleracea var capitata L. leaves confers antixenosis to the cabbage aphid,
Brevicoryne brassicae L. (Singh and Ellis, 1993). Sorghum genotypes with glossy leaf trait
(light, yellow, shiny, and erect leaves) (Figure 6.1) are nonpreferred for oviposition by sorghum
shoot fl y, Atherigona soccata (Rondani) as compared to genotypes with dark green,
drooping, and nonshiny leaves (Sharma and Nwanze, 1997). Plants having yellowish green
leaves are nonpreferred for oviposition by pod borer, Helicoverpa armigera (Hubner) as