A Comparison of Peanut Multilines and Component Lines across Environments 1

Abstract

In peanuts (Arachis hypogaea L.) a high degree of phenotypic similarity among components of multiline cultivars is necessary in order to meet the demands of industry. To achieve this, the compositional scheme for peanut multilines has utilized sibling lines composited between the F4 and F8 generations. As a result, the alleged enhancement of stability may be reduced due to a lack of genetic heterogeneity among component lines, which abates an important advantage of multiline cultivars. This study was conducted to examine the relationship among sibling components of two peanut multilines and to determine if the multilines perform in a more stable manner across environments than any single component. Partitioning of genotype ✕ environment (GE) interaction sum of squares, regression analyses, and stability variances were used to assess stability over environments (2 years, 4 locations) for two multilines and their four components. For one multiline, three of four component lines were not significantly different from the multiline for yield nor did deviations from regression and stability variances differ among components. Conversely, components of the second multiline displayed significant variability for yield, regression coefficients and deviations from regression. However, the multiline performed in a stable manner with relatively high yields and low deviations from regression. Mean yields, regression coefficients, and deviations from regression were shown to be useful parameters in the formation of a multiline. Joint regression analysis and GE partitioning techniques were useful in determining the nature and origin of the GE among groups of late generation segregates. Although additional studies are needed, these data indicate that the compositional scheme for peanut multilines is a feasible method to circumvent GE effects. This study, however, suggests that pure lines of peanuts can be identified that are as stable across environments as multilines.