Evaluation of hybrid maize tolerance under low nitrogen condition based on stress tolerant index and stress susceptibility index

Abstract

Nitrogen (N) deficiency in maize could cause a yield decrease than normal conditions. Yield reduction is one of the main concerns of plant breeders in stress conditions selection. This study aimed to identify the low N tolerant hybrid maize. This research was conducted at the IP2TP field station of the Indonesian Cereal Research Institute in Maros, South Sulawesi, from June to October 2021. The experiment was arranged in the study using a nested Randomized Complete Block Design (RCBD). Replication was nested in the level of N fertilizer. Seventy-five maize genotypes and two levels of N fertilizer (N1=100 kg N ha−1 and N2=200 kg N ha−1) were used in this study. Each genotype was replicated two times at each fertilizer level. The variable observed was maize yield. Two tolerance indexes, such as the Stress Tolerant Index (STI) and Stress Susceptibility Index (SSI), were used to determine the maize’s tolerance to low N conditions. The results showed that the test hybrids showed tolerance level variations according to the SSI and STI indices. Seven hybrids were tolerant, and ten were susceptible based on two indices. Six hybrids were tolerant according to SSI but susceptible according to STI. Five hybrids were tolerant based on STI but susceptible based on SSI. Hybrid CML 465 x AVLN 109-3, AVLN 109-3 x VL1016518, CAL 1471 E x B 11, AVLN 86-4 X 1026-12, CML 465 x CAL 1473, VL1016518 x P7 and CML 161X CI 32 hybrids were tolerant maize based on SSI and STI indexes. These hybrids can be used as low N tolerant maize breeding materials in the next breeding program.