Genetic variation among maize inbred lines and topcrosses for late sowing in semi-arid lands

DE LA TORRE MARÍA VIRGINIA; BONGIANINO NICOLÁS FRANCISCO; CONRERO JUAN MARCELO; BIASUTTI CARLOS ALBERTO

Simposio; 1st Plant Breeding Symposium; 2021

The aims of this study were to determine genetic variation maize inbred lines from diverse background and topcrosses and identify appropriate parents for obtaining hybrids cultivars for late sowing in semi-arid lands. Twenty-eight maize inbred lines and their respective topcrosses from diverse backgrounds were used in this study. Two single cross hybrid cultivars were used as controls. Experiments were established in Cordoba, Argentine (31° 29? LS; 64° 00? LO, 425 msm above sea level) during 2017 and 2018 growing seasons. Inbred lines and topcrosses were planted in two separate experiments using completely randomized block designs with two replications in each year. Data were taken on grain yield (qq ha-1), plant height (PH) (cm), number of kernels per ear (NKE), ear length (EL) (cm), number of rows per ear (NRE), ear diameter (ED) (cm), ear height (EH) (cm), number of leaves above single ear (NLSE), number of panicle branches (NPB), foliar elongation (FE) (cm), foliar temperature (FT) (ºC), kernel length (KL) (cm), were estimated from a sample of 10 plants from each plot. Data were analyzed by principal components and cluster analyses. InfoStat professional statistical software was used. Genetic differences were found through cluster analysis. The most different lines were L25A, L87, L84, L83A, L85A, L13 and L11 while the rest of the lines were found forming groups (Figure 1). Differences between lines x tester crosses were projected on CP1 (32.8%) and CP2 (24.4%), explaining 57% of the total variability (Figure 2). Cross 4 (L11xT) was the best performance compared to the rest, showing greater proximity to the T1 and T2 controls. Then L84xT (22) was located in the second place. The lines showed genetic variability for all the traits evaluated. Inbred lines L11 and L84 showed genetic divergence with respect to the rest and expressed superior behavior in crosses with the tester. Therefore, they have potential as future progenitors for hybrid crosses.