Contents - Faperta

158 Biotechnological Approaches for Pest Management and Ecological Sustainability
FIGURE 6.1 Glossy leaf trait in sorghum associated with resistance to sorghum shoot fl y, Atherigona soccata.
compared to the cultivars with dark green leaves (Sundramurthy and Chitra, 1992; Jing
et al., 1997). Red strains of Gossypium arboreum L. in cotton are resistant to spotted bollworm,
Earias vittella (Fab.) (Sharma, Agarwal, and Singh, 1982). In groundnut, genotypes with
dark green and smaller leafl ets are less damaged by H. armigera than those with longer
shoots, and larger and light green leafl ets (Arora, Kaur, and Singh, 1996).
Phenological Traits
Rice varieties with tight leaf sheaths are less susceptible to the Asiatic stem borer, Chilo
suppressalis (Walker) (Patanakamjorn and Pathak, 1967), while spring wheat varieties with
tight leaf sheaths are resistant to leaf miner, Hydrellia griseola (Fall) (Zhu, 1981). In sorghum,
varieties with short and light glumes are resistant to sorghum midge, S. sorghicola (Sharma,
Vidyasagar, and Leuschner, 1990), while those with longer glume covering of the grain are
less susceptible to the African head bug, Eurystylus oldi (Poppius) (Sharma et al., 1994).
Sorghum genotypes with compact panicles are more susceptible to H. armigera than those
with loose panicles (Sharma, Lopez, and Vidyasagar, 1994). Silica deposition on the fourth
and fi fth leaves of sorghum is associated with resistance to shoot fl y, A. soccata (Ponnaiya,
1951; Bothe and Pokharkar, 1985), while high silica content has been reported to interfere
with feeding by the Asiatic stem borer, C. suppressalis (Pathak et al., 1971) in rice, and shoot
borer, Chilotraea infuscatellus Snellen in sugarcane (Rao, 1967).
In cotton, earliness, smaller leaves, and nonclustered bolls provide a mechanism to avoid
damage by bollworms. Smooth and okra leaves, frego-bract, nectarlessness, open canopy,
and naked seed characteristics are associated with resistance to H. armigera (Khalifa, 1979).
A combination of frego-bract, okra leaf, red leaf, and nectarlessness contribute to maximum
reduction of damage by H. armigera (Bhat and Jayaswal, 1988; Wu, Cai, and Zhang, 1997).
The nectarless trait in cotton is associated with reduced numbers of tobacco budworm,
Heliothis virescens (F.), and pink bollworm, Pectinophora gossypiella (Saunders) (Lukefahr,
Houghtaling, and Graham, 1975).
Husk tightness in maize imparts resistance to corn earworm, Helicoverpa zea (Boddie)
(Wiseman and Isenhour, 1994; Widstrom et al., 2003b), and has also been found to result in
reduced levels of afl atoxin B1 (Widstrom et al., 2003a). Pearl millet varieties with a dense
covering of anthers and without awns are more susceptible to H. armigera than the varieties
without anther cover and awns (Sharma and Youm, 1999). Pigeonpea genotypes with
determinate growth habit, clustered pods, and dense plant canopy are more susceptible to
pod borers, H. armigera and Maruca vitrata (Geyer) than genotypes with nonclustered pods
(Sharma, Bhagwat, and Saxena, 1997), while the genotypes with smaller pods, pod wall
tightly fi tting to the seeds, and a deep constriction between the seeds are less susceptible