Quantitative genetic studies in flue-cured tobacco (Nicotiana tabacum). I. Agronomic characters

Abstract

A five parent diallel cross in flue-cured tobacco (Nicotiana tabacum L.) was grown over a 2-year period at the Delhi Research Station. Griffing's (1956) and Hayman's (1954) analyses indicated that general combining ability explained a high proportion of the variability of most of the agronomic characters, suggesting that additive gene action was the major component in determining the expression of these characters. This was substantiated by high narrow-sense heritability estimates. Specific combining ability components were small suggesting that dominance, if any, played a minor role. The WrVr graphic analysis of Hayman indicated a general lack of nonallelic interaction. Phenotypic, genotypic, and additive genetic correlations explained covariation among pairs of characteristics in an almost analogous manner. Implications of the genetic nature of variation in terms of practical utilization by the breeder are discussed.

Study of inheritance of some agronomic and morphological traits in burley tobacco by graphic analysis of diallel cross

“…According to the previous investigations, the inheritance of plant height (Šmalcelj 1983, Shoai Daylami and Honarneja 1996, Butorac et al 1999 and days to flowering (Espino and Gil 1980, Ibrahim and Avravtovscukova 1982, Pandeya et al 1983, Butorac et al 1999) is more influenced by nonadditive variance, too. Our present results also point to the same conclusion.…”

“…Some previous investigations of the inheritance of major tobacco traits (yield, plant height, leaf number, days to flowering, leaf length and width) using graphic analysis show contradictory results. Starting from yield, a major tobacco trait, according to the studies made so far overdominant inheritance was estimated by graphic analysis (Jung et al 1982, Šmalcelj 1983, Butorac et al 1999), but partial dominance was also found (Gopinath et al 1966, Shamsuddin et al 1980, Pandeya et al 1983). In our present investigations, according to the graphic analysis, yield was inherited overdominantly in both years of investigation.…”

“…Some studies using graphic analysis indicate that nonadditive variance plays a somewhat greater role in the inheritance of plant height (Šmalcelj 1983, Shoai Daylami and Honarneja 1996, Butorac et al 1999) and days to flowering (Espino and Gil 1980, Ibrahim and Avravtovscukova 1982, Pandeya et al 1983, Butorac et al 1999. In most papers, independently of tobacco type, additive variance in inheritance of leaf number (Shamsuddin et al 1980, Šmalcelj 1983, Shoai Daylami and Honarneja 1996 and leaf width was estimated (Gopinath et al1966, Espino and Gil 1980, Ibrahim and Avravtovscukova 1982.…”

“…In most papers, independently of tobacco type, additive variance in inheritance of leaf number (Shamsuddin et al 1980, Šmalcelj 1983, Shoai Daylami and Honarneja 1996 and leaf width was estimated (Gopinath et al1966, Espino and Gil 1980, Ibrahim and Avravtovscukova 1982. The graphic method indicates overdominant inheritance of yield (Jung et al 1982, Šmalcelj 1983, Butorac et al 1999, and also the participation of partial dominance (Gopinath et al 1966, Shamsuddin et al 1980, Pandeya et al 1983). Leaf length is also inherited overdominantly (Ibrahim andAvravtovscukova 1982, Butorac 1997) and partially dominantly (Gopinath et al 1966, Pandeya et al 1983.…”

“…The graphic method indicates overdominant inheritance of yield (Jung et al 1982, Šmalcelj 1983, Butorac et al 1999, and also the participation of partial dominance (Gopinath et al 1966, Shamsuddin et al 1980, Pandeya et al 1983). Leaf length is also inherited overdominantly (Ibrahim andAvravtovscukova 1982, Butorac 1997) and partially dominantly (Gopinath et al 1966, Pandeya et al 1983. Ukai (1991) investigated the influences of environmental variations involved in the values of a diallel table on the (Wr Vr) graph.…”