Agronomic performance of purple maize (Zea mays L.) inbred families in the semiarid region of Argentina

MONSIERRA, LUISINA; BERTOLA, AGUSTINA DEL PILAR; QUIROGA, NATALIA; PÉREZ, GABRIELA TERESA; MANSILLA, PABLO SEBASTIÁN

Córdoba

Simposio; Primer Simposio Internacional de Mejoramiento Genético Vegetal; 2021

Instituto Nacional de Tecnología Agropecuaria

Objective: The objective of this study was to evaluate the agronomic performance of purple maize inbred families in the central semiarid region of Argentina.Materials and methods: Two inbred generations (S1 and S2) of eleven purple maize families were evaluated in two crop years (S1 in 2019 and S2 in 2020). Families were sown (early-January of each year) in the experimental station of Facultad de Ciencias Agropecuarias, Universidad Nacional de Córdoba, Argentina (31°28? 49.42? S, 64°00? 36.04? W), under a randomized complete block design with two replications. The field is located in the province of Córdoba, the central semiarid Argentinian region, with an altitude of 425 m.a.s.l. The soil is Entic Haplustoll and well supplied with organic matter. The assays were performed under rainfed conditions without nitrogen fertilization. Measured variables in genotypes: plant height (PH), length of leaves (LL), ears per plant (NE), cob length (CL), cob diameter (CD), weight of 100 grains (W100) and male and female flowering periods. The grain yield (GY) of each family was estimated (q ha-1) and adjusted to 14% moisture. Data were analyzed by Analysis of Variance (ANOVA) and the comparison test of Di Rienzo, Guzmán and Casanoves (DGC) (p < 0.05) was applied. Minimum, maximum and coefficient of variation (CV) of each trait were established. Infostat/Professional Statistical software (Facultad de Ciencias Agropecuarias, Universidad Nacional de Córdoba) was used.Results: Significant differences were obtained between families in most of features of plants and cobs, both in S1 and S2 generation. Similarly, significant differences were obtained between years and family x year interaction, except to NE (Table 1). Traits measured significantly decreased in S2 generation in relation to S1, probably caused both by inbreeding effects, as well as environmental influence such as prevailing drought climatic conditions during 2020. S2 generation presented higher CV than S1, indicating higher variability between genotypes in S2. There was a delay in period from sowing to flowering in S2 compared to S1 (61 to 75 days in S1 and 75 to 85 days in S2). Consistently, a marked reduction in grain yield of S2 families was observed, probably due to inbreeding depression and drought environmental conditions. A great variability in grain color was observed within each family and inbred generation, probably as response to segregations and genetic variations and environmental effects.Conclusions: The inbred families presented differences in their agronomic performance. These differences will facilitate the identification of superior genotypes to continue with the inbreeding and genetic improvement of these materials in the semiarid region.