Variability in European Maize (Zea mays L.) Landraces under High and Low Nitrogen Inputs

Abstract

An European maize (Zea mays L.) landrace core collection (EMLCC) was formed with samples from several countries. Evaluation of the EMLCC may contribute to broad the genetic base of maize breeding programs. The objective of this study was to assess the variability of EMLCC under low nitrogen (N) in relation to high N input. Eighty-five landraces of the EMLCC, grouped in four maturity groups, and three check hybrids were evaluated for response to low (0 kg ha À1 ) and high (150 kg ha À1 ) N in Spain and Greece. Five plant size traits (plant height, ear height, leaf length, leaf width and leaf area index), two grain traits (1000-kernel weight and grain yield), and two agronomic traits [growing degree units (GDU) and lodging] were studied. Overall means of plant size and grain traits increased when genotypes were grown at 150-N relative to 0-N input. The relative increase for grain traits was smaller in landraces than in hybrids. This suggests that landraces had lower grain yield response to N supply compared to hybrids. Linear regressions of plant size traits on GDU indicated that vegetative development was primarily associated with flowering lateness. The maturity group was the main source of variation for all traits. Landrace variability within maturity groups was significant for all traits across environments, despite significant landrace · environment interactions. Estimates of genetic and genotype · environment variances, and heritabilities at both high and low N inputs were not significantly different from each other. However estimates were generally larger at high N. Genetic and phenotypic correlation coefficients between the two N levels were very high for all traits.

QTL mapping of nutrient components in maize kernels under low nitrogen conditions

“…The importance to crop yield of adequate soil N has been well documented, as many studies have demonstrated that low N resulted not only reduced grain yield, but also affected nutrient levels in kernels, particularly protein content (Bertin and Gallais 2000, Feil et al. 2005, Ferro et al. 2006).…”

“…The importance to crop yield of adequate soil N has been well documented, as many studies have demonstrated that low N resulted not only reduced grain yield, but also affected nutrient levels in kernels, particularly protein content (Bertin and Gallais 2000, Feil et al 2005, Ferro et al 2006. Interestingly, grain yield did not correlate well with any quality parameters (£0.30), suggesting that both high grain yield and superior grain quality can be produced simultaneously to some degree The correlations for the four measured traits between two high and low N treatments in two locations.…”

Unlocking the Genetic Diversity of Maize Landraces with Doubled Haploids Opens New Avenues for Breeding

“…Broadening the genetic base of the elite breeding pool through introgression of additional material from European landraces might, therefore, be of great interest [6]. Extensive characterization studies of landraces for morphological traits [10], [11], early growth and cold tolerance [12]–[16], adaptation to low nitrogen fertilization [17], [18], and pest resistance [19], [20], often identified landraces with desirable traits. Germplasm collections of European landraces were also extensively genotyped with molecular markers to determine their origin, relatedness, and degree of genetic diversity [1], [7]–[9], which revealed their broad genetic diversity and potential for further mining of favorable alleles.…”

Molecular caracterization of a corn core collection–landraces subgroup

“…For example, Malvar et al (2007) assayed the capacity of accessions in the European Union Millet Landrace Collection to survive infestation by millet borers (Ostrinia nubilalis Hbn. ), an important regional pest, while Ferro et al (2007) worked with the same germplasm collection under field conditions, and analyzed productivity in high-and low-dose nitrogen situations, a high-percentage contributor to overall production costs, and a potential environmental pollutant whose presence in waterbodies can result in their eutrophication.…”

“…), importante praga regional. Ferro et al (2007) trabalharam com a mesma coleção de germoplasma em condições de campo, analisaram a produção nas situações de alta e baixa dose de nitrogênio, nutriente de maior valor para o custo de produção e que pode ser poluidor de ambiente, resultando na eutrofização de corpos d'água.…”