Inheritance of resistance to yellowberry in durum wheat

Abstract

Resistance to grain yellowberry in durum wheat (Triticum durum Desf.) was investigated using generation mean analysis in four resistant or intermediate-resistant X susceptible crosses. Significant differences in resistance were observed between generations in all crosses. Generation mean analysis indicated a complex gene action controlling this trait, with additive, dominance and epistatic effects. Additive (d) components were positive in all crosses, suggesting that additive effects contributed more to resistance than to susceptibility. In contrast dominance (h) effects were negative in majority of crosses. The minimum number of genes controlling resistance was estimated at 1.41. Mid-parent heterosis ranged from 28.5 to 52.1 indicating dominance of resistance. Broad-sense heritability estimates ranged from 0.52 to 0.88, while narrow-sense heritability estimates ranged from 0 to 0.79. Estimates of genetic gain for resistance ranged from low to high. Estimates of broad and narrow sense heritabilities indicated that genetic effects were larger than environmental effects. Additive effects represented the largest components of genetic effects.

Epistasis and heritability of resistance to Phytophthora nicotianae in pepper (Capsicum annuum L.)

“…Examples are wheat and leaf rust (Ezzahiri and Roelfs 1989), wheat and yellowberry (Bnejdi and El Gazzah 2008), common bean and anthracnose (Marcial and Pastor 1994), barley and Fusarium head blight (Flavio et al 2003), chickpea and Botrytis cinerea (Rewal and Grewal 1989), and pepper and Phytophthora capsici (Bartual et al 1994). …”

Impact of Epistasis in Inheritance of Quantitative Traits in Crops

“…Recent studies suggest that epistatic effects are present for inheritance of quantitative traits in many species. Examples are wheat (resistance to leaf rust, Ezzahiri and Roelfs 1989), wheat (resistance to yellowberry, Bnejdi and El Gazzah 2008), common bean (resistance to anthracnose, Marcial and Pastor 1994), barley (resistance to Fusarium head blight, Flavio et al 2003), chickpea (resistance to Botrytis cinerea, Rewal and Grewal 1989), and pepper (resistance to Phytophthora capsici, Bartual et al 1994). …”

“…Therefore, the bias in the estimate of the additive variance when assuming the additive-dominant model is considerable. The preponderance of epistasis effect in the inheritance of quantitative trait in crops was recently reported by many geneticists (Pensuk et al, 2004;Bnejdi and El Gazzah, 2008;Bnejdi and ElGazzah, 2010a;Shashikumar et al 2010). Epistasis can have an important influence on a number of evolutionary phenomena, including the genetic divergence between species.…”

“…Two crosses/two sites Number of head per plant , Spiklets per spike and Number of grains per spike (Bnejdi and El Gazzeh 2010b) Four crosses/ one site Resistance to yellowberry (Bnejdi and El Gazzah, 2008) Four crosses/ one site Resistance to yellowberry Four crosses/ Two sites Grain protein content (Bnejdi and El Gazzeh, 2010a) …”

Appraisal of gene action for indeterminate growth in mungbean [Vigna radiata (L.) Wilczek]

“…Additive and non-additive gene actions control the inheritance of plant height in mungbean (Singh et al, 2007) and harvest index in wheat (Chand and Dawa, 1996). Several geneticists witnessed the existence of epistasis in the inheritance of quantitative character in different crops (Pensuk et al, 2004; Bnejd and El- Gazzah, 2008, 2010; Shashikumar et al, 2010). Accumulation and clustering of interacting sets of genes with additive influence could provide a path for the genetic improvement of quantitative traits.…”