Agricultural practices should be approached with environmental-friendly strategies, able to restore soil organic matter and reduce the greenhouse gas emissions. The main objective of this study is to evaluate the environmental benefits, in terms of CO₂ emissions and carbon balance, of some agricultural practices for potato cultivation. A randomized complete block design was adopted where the treatments were: (a) tillage systems (plowing; subsoiler and spading); (b) fertilizer sources (mineral and organic). All treatments were replicated three times. Potato yield and its carbon content, soil CO₂ emissions, temperature, and volumetric water content were measured. The CO₂ emissions were higher in organic than in mineral fertilizer (0.60 and vs. 0.77 g m⁻² h⁻¹, respectively), while they were low in spading compared to the other soil tillage (0.64 vs. 0.72 g m⁻² h⁻¹, respectively). Carbon input was the highest in plowing and organic fertilizer 4.76 and 5.59 Mg C ha⁻¹, respectively. The input/output ratio of carbon varied according to the main treatments. The findings suggest that spading tillage and organic fertilizer might result in environmental and agronomical benefits, further research should be performed to evaluate to possibility to extend the results to other environments and crops.

Background

Salinity is a significant environmental stress factor limiting crops productivity. Barley (Hordeum vulgare L.) has a natural tolerance to salinity stress, making it an interesting study object in stress biology research. In the present study, for the first time the effect of salinity stress on barley inflorescence developmental stages was investigated. Five spring barley genotypes irrigated with saline water (12.5 ds/m NaCl) were compared to controls treated with normal tap water. We measured abscisic acid (ABA) concentrations in the apical, central and basal sections of the immature inflorescence at green anther (GA) stage. The role of ABA in spikelet primordia development, atrophy and abortion and final yield was evaluated.

Results

A time course experiment starting from double ridge until green anther (GA) stages revealed that salinity reduced the length of spike developmental stages in all genotypes causing shortened of the plant life cycle. The shortened plant life cycle negatively affected plant height and number of tillers/plant. Salinity also affected spikelet primordia development. In both control and salinity treated plants apical spikelet abortion started in late awn primordium (AP) stage. However, under salinity treatment, significantly more spikelets were aborted, thus directly affecting plant yield potential. ABA, which plays a role in the spikelet/floret abortion process, was markedly elevated in the base and apex of salt treated spikes correlating with an increased spikelet abortion in these regions.

Conclusions

Overall, salinity treatment reduced all plant and yield-related parameters investigated and turned some of the correlations among them from positive to negative or vice versa. Investigations of ABA role in floral development and phase duration of barley spike showed that, ABA regulates the spikelet/floret abortion process affecting the yield potential under salinity and control conditions.

Understanding how biological systems evolve across changing conditions has been a crucial focus of research. Mutations change the genetic context in which genes are expressed and yet the mechanisms underlying mutation fitness are still unclear. We use the sweet corn mutant sugary1 (su1) as a model for understanding the genetic regulation of mutant fitness, focusing on the mutant × genotype interaction across diverse environments. In a previous work, we identified quantitative trait loci (QTLs) affecting fitness in a mapping population of recombinant inbred lines (RILs) derived from a cross between field corn (B73) × sweet corn (P39 or IL14h) parents; however, the epistatic effects of these QTLs on su1 fitness were not investigated. In the present study, we estimated fitness for two seed production environments. Viability of su1 is under genetic and environmental controls, regulated by multiple genes with minor contributions, and these genes depend on the genotype into which the mutation is introduced and on the environment. Some QTLs were in linkage disequilibrium with the maize gene Su1 and had epistatic effects on su1 fitness. These QTLs could be used by sweet corn breeders by combining the most favorable alleles associated with su1 viability in breeding new genotypes from field × sweet corn crosses. These results also have implications for mutagenesis breeding or genome editing because the epistatic effects of the target genome on the new alleles generated by these techniques could affect the success of the breeding program.