Genotype ✕ Environment Interactions in Burley Tobacco Variety Tests¹

Abstract

The objectives of our study were to estimate the components of variance for burley tobacco (Nicotiana tabacure L.) grown at six locations for 3 years and to determine their implications on testing procedures.Eleven commercial hurley tobacco cultivars were grown at 6 locations in 4 states for 3 years. For each experiment we recorded the number of days to flowering; number of leaves and plant height after topping; length and width of fifth leaf from the top; internode length; yield of cured leaf; percent total nitrogen; percent α‐amino nitrogen; water‐soluble acids; pH; and percent ash, K2O, nicotine, and secondary amine alkaloids. Estimates of variance components and correlations among years and among locations were computed for each variable.Estimates of variance components for cultivars were highly significant for all traits. Cultivar ✕ location and cultivar ✕ year interactions were relatively small for all traits. Second‐order interactions were large relative to first‐order interactions for most variables, but in most instances were much smaller than the component for cultivars.The cultivars source of variation for yield was subdivided to elucidate the variance among F1 hybrids and pure lines and their interactions with environments. The location ✕ hybrid mean square was statistically significant, but the one for location ✕ pure lines was not. These results suggest that some hybrids may not have as much internal buffering capacity as pure lines in burley tobacco.Our results show that years and locations may be considered random environments and may be used interchangeably. Adding more years costs more in time and money than does adding locations; therefore, using several locations for 2 years seems best for testing burley tobacco.

Genotype × Environment Interactions in Sorghum Variety Tests in the Sudan Central Rainlands

“…The significance of genotype x environment interactions in variety-evaluation programmes is well recognized. Estimates of these interactions have been used to obtain information on the optimum allocation of replications, locations and years in variety trials in several crops including cotton (Miller et al, 1959), barley (Rasmusson and Lambert, 1961), soyabean (Schutz and Bernard, 1967), sorghum (Rao, 1970) and tobacco (Gupton et al, 1974). Finlay and Wilkinson (1963), Eberhart and Russel (1966) and others have suggested statistical techniques for partitioning the genotype x environment interactions into parameters that permit a study of phenotypic stability of genotypes.…”

Genetic Variation for Agronomic Characters in a Burley Tobacco Synthetic Following Recurrent Selection for Increased Black Shank Resistance

“…GuPTON et al (1974) tested 11 cultivars at six locations in four states for three years. The cultivar X location interaction was significant for only four traits out of 16 and days to flower was the only character to show a cultivar X year interaction.…”

Breeding cereal rye (Secale cereale) for quality traits

“…The interaction of genotype and environment is an issue that has permeated the plant and animal breeding literature for more than 75 years. The volume of literature devoted to G×E in plants is overwhelming, and yet we know that for certain crops (e.g., tobacco ( Nicotiana tabacum L.; Gupton et al., 1974) G×E interaction is minimal, while for others like corn ( Zea mays L.) G×E is quite problematic (Eberhart & Russell, 1969). An examination of the recent literature devoted to rye G×E indicates that this crop resides in the middle of this spectrum.…”