Influence of Cytoplasmic Male Sterility on Expression of Different Mechanisms of Resistance in Sorghum to Atherigona soccata (Diptera: Muscidae)

Abstract

Atherigona soccata (Rondani) (Diptera: Muscidae) is one of the most important pests of sorghum, Sorghum bicolor (L.) Moench, in Asia, Africa, and the Mediterranean Europe. Exploitation of cytoplasmic male sterility (CMS) for hybrid production has resulted in considerable narrowing of the genetic base and may increase the vulnerability of this crop to insect pests. Therefore, we studied the expression of different mechanisms of resistance in sorghum to A. soccata in CMS (A) and maintainer (B) lines of 12 genotypes under field and greenhouse conditions. The CMS lines of A. soccata-resistant genotypes were preferred for oviposition (78.5 versus 71.5% plants with eggs) and suffered greater deadheart incidence (47.6 versus 41.6%) than the corresponding maintainer lines, whereas such differences were not apparent in CMS lines belonging to the susceptible genotypes (92.7 versus 92.3% plants with eggs and 75.6 versus 74.6% deadhearts) under multichoice field conditions. Similar differences also were observed under controlled conditions in the greenhouse. The larval period (9.0 versus 8.8 d) and pupal mortality (18.4 versus 13.4%) were greater on maintainer lines than that on the CMS lines in the resistant group. The male and female pupal weights, fecundity, and antibiosis index were greater on the CMS than on the maintainer lines. The maintainer lines showed better recovery resistance than the CMS lines, but no such differences were observed in tiller deadhearts. The differences in susceptibility to A. soccata were greater in the A. soccata resistant CMS and maintainer lines than in the CMS and maintainer lines belonging to susceptible genotypes. Conversion of A. soccata-resistant genotypes into alternate less susceptible cytoplasmic backgrounds may be undertaken for developing sorghum hybrids with stable resistance to A. soccata.

Physico-chemical mechanisms of resistance to shoot fly, Atherigona soccata in sorghum, Sorghum bicolor

“…Oviposition non-preference (antixenosis), antibiosis and tolerance are the major components of resistance in sorghum to shoot fly (Doggett et al 1970;Raina et al 1981;Sharma and Nwanze 1997;Dhillon et al 2005Dhillon et al , 2006aSivakumar et al 2008). As a result of shoot fly damage to the main shoot, more numbers of tillers are produced, depending on the Physico-chemical mechanisms of resistance in sorghum to shoot fly S. K. Chamarthi et al…”

Inheritance of Resistance to Sorghum Shoot Fly, Atherigona soccata in Sorghum, Sorghum bicolor (L.) Moench

“…Most of the crosses and their reciprocals showed resistance to shoot fly, suggesting that shoot fly resistance can be easily transferred into the progenies. Most of the crosses exhibited oviposition non-preference and tolerance mechanisms of resistance, which are the major components of resistance in sorghum to shoot fly (Doggett et al, 1970; Raina et al, 1981; Sharma and Nwanze, 1997; Kamatar et al, 2003; Dhillon et al, 2005, 2006b; Sivakumar et al, 2008). F 1 hybrids based on shoot fly-resistant parents exhibited leaf glossiness, high plant vigor, leafsheath pigmentation, and high trichome density across seasons, suggesting that both the parents should be resistant to shoot fly.…”

“…Genotypes with significant negative gca effects were good combiners for shoot fly resistance. Genotypes with negative gca effects for plants with shoot fly eggs, number of shoot fly eggs/plant, shoot fly deadhearts, leaf glossy score, plant vigor score and leafsheath pigmentation, significant positive gca effects for trichome density can be selected and effectively utilized in the breeding program (Sharma et al, 1977; Hallali et al, 1982; Dhillon et al, 2006b). The crosses with negative sca effects for leaf glossy and plant vigor scores can be utilized in hybrid breeding process.…”

“…Leafsheath pigmentation was visually scored on a 1-3 rating scale (1 = leafsheath with deep pink pigmentation, and 3 = green leafsheath and no pink pigmentation) at 7 DAE (Dhillon et al, 2006b). Seedling vigor was recorded at 10 DAE on 1–3 scale (1 = high seedling vigor, and 3 = poor seedling vigor) (Sharma et al, 1992).…”

Ranking the value of germplasm: new oil palm (Elaeis guineensis) breeding stocks as a case study

“…There has also been very little diversification of oil palm seed production since the 1960s, which was based mainly on 'Deli' × La Mé and 'Deli' × Congo/AVROS crosses (Cochard et al, 2009). Genetic vulnerability has been similarly reported in a wide array of crops that have also undergone significant bottlenecks, including long-lived perennials such as cashew (Cardosa et al, 2010), banana (Arvanitoyannis et al, 2008), castor (Sujatha et al, 2008) and fig (Chatti et al, 2008), as well as many staple food crops including maize (Bellon et al, 2011), wheat (Fu & Somers, 2009), barley (Mikel & Kolb, 2008), rice (Zhu et al, 2000) and sorghum (Dhillon et al, 2006). This trait has a major effect on oil extraction and processing, and is controlled by a single Mendelian gene (Sh) which gives rise to three phenotypes: dura (thick-shelled; ShSh), tenera (medium-shelled seed; Shsh) and pisifera (shell-less; shsh) types (Corley & Tinker, 2003).…”