Molecular markers reliably predict post-harvest deterioration of fresh-cut lettuce in modified atmosphere packaging

Fresh-cut lettuce is popular,but highly perishable product.Genetic studies of two bi-parental populations derived from crossing parents with rapid and slow rates of deterioration showed that the deterioration rate is a heritable trait(broad spectrum heritability,H2 of 0.56–0.87).The major genetic determinant of the deterioration rate in both populations was the quantitative trait locus(QTL),qSL4,located on linkage group 4.This QTL explained 40–74%of the total phenotypic variation of the trait in the two populations.Saturating the qSL4 region with single-nucleotide(SNP)markers allowed detection of six haplotypes in a set of 16 lettuce accessions with different rates of deterioration.Three of the haplotypes were always associated with very rapid rates of deterioration,while the other three haplotypes were associated with slow rates of deterioration.Two SNPs located 53 bp apart were sufficient to separate the 16 accessions into two groups with different rates of deterioration.The accuracy of markers-trait association was subsequently tested on 350 plants from seven F2 families that originated from crossing parents with different rates of deterioration.The H2 of deterioration rate in these seven families ranged from 0.64 to 0.90.The SNP-based analysis accurately identified individuals with rapid,intermediate,and slow rates of deterioration in each family.Intermediate rate of deterioration was found in individuals having heterozygous alleles at qSL4,indicating an additive effect of the alleles.The assay can be used for fast,accurate,and reliable identification of deterioration rate after processing for salad.

Microbial response to designer biochar and compost treatments for mining impacted soils

The Oronogo-Duenweg mining belt is a designated United States Environmental Protection Agency Superfund site due to lead-contaminated soil and groundwater by former mining and smelting operations.Sites that have undergone remediation-in which the O,A,and B horizons have been removed alongside the lead contamination-have an exposed C horizon and are incalcitrant to revegetation efforts.Soils also continue to contain quantifiable Cd and Zn concentrations.To improve soil conditions and encourage successful site revegetation,our study employed three biochars,sourced from different feedstocks(poultry litter,beef cattle manure,and lodgepole pine),at two rates of application(2.5%,and 5%),coupled with compost(0%,2.5%and 5%application rates).Two plant species-switchgrass(Panicum virgatum)and buffalograss(Bouteloua dactyloides)-were grown in the amended soils.Amendment of soils with poultry litter biochar applied at 5%resulted in the greatest reduction of soil bioavailable Cd and Zn.Above-ground biomass yields were greatest with beef cattle manure biochar applied at 2.5%with 5%compost,or with 5%biochar at 2.5%and 5%compost rates.Maximal microbial biomass was achieved with 5%poultry litter biochar and 5%compost,and microbial communities in soils amended with poultry litter biochar distinctly clustered away from all other soil treatments.Additionally,poultry litter biochar amended soils had the highest enzyme activity rates forβ-glucosidase,N-acetyl-β-D-glucosaminidase,and esterase.These results suggest that soil reclamation using biochar and compost can improve mine-impacted soil biogeophysical characteristics,and potentially improve future remediation efforts.