Analysis of global research on vegetable seedlings and transplants and their impacts on product quality.

BACKGROUND: Previous research has established that using high-quality planting material during the early phase of vegetable production significantly impacts success and efficiency, leading to improved crop performance, faster time to harvest and better profitability. In the present study, we conducted a global analysis of vegetable seedlings and transplants, providing a comprehensive overview of research trends in seedling and transplant production to enhance the nutritional quality of vegetables. RESULTS: The analysis involved reviewing and quantitatively analysing 762 articles and 5248 keywords from the Scopus database from 1971 to 2022. We used statistical, mathematical and clustering tools to analyse bibliometrics and visualise the most relevant research topics. A visualisation map was generated to identify the evolution of keywords used in the articles, resulting in five clusters for further analysis. Our study highlights the importance of the size of seed trays for the type of crop, the mechanical seeder used and the greenhouse facilities to produce desirable transplants. We identified grafting and light-emitting diode (LED) lighting technology as rapidly expanding technologies in vegetable seedlings and transplant production used to promote plant qualitative profile. CONCLUSION: There is a need for sustainable growing media to optimise resources and reduce input use. Thus, applying grafting, LED artificial lighting, biostimulants, biofortification and plant growth-promoting microorganisms in seedling production can enhance efficiency and promote sustainable vegetable nutritional quality by accumulating biocompounds. Further research is needed to explore the working mechanisms and devise novel strategies to enhance the product quality of vegetables, commencing from the early stages of food production. © 2024 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Understanding the Postharvest Phytochemical Composition Fates of Packaged Watercress (Nasturtium officinale R. Br.) Grown in a Floating System and Treated with Bacillus subtilis as PGPR.

The physiological changes and phytochemical pathways of processed watercress (Nasturtium officinale R. Br.) undergone during storage are not well known. The objective of this work was to evaluate the respiration rate and the inherent and external quality of watercress inoculated with B. subtilis and packaged as a fresh-cut product and stored at 4 °C for 11 days. Watercress was grown using continuous flotation (FL) in a greenhouse using substrate disinfection and inoculated or not with Bacillus subtilis as a plant-growth-promoting rhizobacteria (PGPR). The fresh-cut watercress respiration rate and phytochemical profile changed during the shelf life. The inherent phytochemical compounds were retained during the storage of the fresh-cut salad bags. The best results were found in watercress grown in a disinfected substrate but were less satisfactory when seeds and substrates were inoculated with PGPR. In general, the external quality and the pigment contents progressively decreased during the shelf life and the browning enzyme activities responsible for phenolic oxidation increased at different intensities throughout storage. At the end of the shelf-life period, the fresh weight loss of the fresh-cut product was less than 1% of the original weight. The results demonstrated that watercress grown in FL is a standardised baby leaf vegetable that is suitable for processing in the fresh-cut industry and for storing for more than 10 days. Unclear results were obtained for Bacillus subtilis in the postharvest period due to the inconsistent responses of the different analysed parameters.

Bacterial and fungal community dynamics during different stages of agro-industrial waste composting and its relationship with compost suppressiveness.

Composting is an advantageous and efficient process for recycling organic waste and producing organic fertilizers, and many kinds of microorganisms are involved in obtaining quality compost with suppressive activity against soil-borne pathogens. The aim of this work was to evaluate the main differences in the effects of three composting piles on the whole bacterial and fungal communities of baby-leaf lettuce crops and to determine the specific communities by high-throughput sequencing related to suppressiveness against the soil-borne plant pathogen Pythium irregulare- (P. irregulare). Compost pile A was composed of 47% vineyard pruning waste, 34% tomato waste and 19% leek waste; pile B was composed of 54% vineyard pruning waste and 46% tomato waste; and pile C was composed of 42% vineyard pruning waste, 25% tomato waste and 33% olive mill cake. The temperature and the chemical properties of the piles were monitored throughout the composting process. In addition, the potential suppressive capacity of the three composts (C_A, C_B and C_C) against P. irregulare in baby-leaf lettuce was assessed. We found that the bacterial community changed according to the composting phases and composting pile and was sensitive to chemical changes throughout the composting process. The fungal community, on the other hand, did not change between the composting piles and proved to be less influenced by chemical properties, but it did change, principally, according to the composting phases. All composts obtained were considered stable and mature, while compost C_C showed higher maturity than composts C_A and C_B. During composting, the three piles contained a greater relative abundance of Bacterioidetes, Proteobacterias and Actinobacterias related to the suppression of soil-borne pathogens such as Pythium irregulare. Composts C_A and C_B, however, showed higher suppressiveness against P. irregulare than compost C_C. Deeper study showed that this observed suppressiveness was favored by a higher abundance of genera that have been described as potential suppressive against P. irregulare, such as Aspergillus, Penicillium, Truepera and Luteimonas.

The influence of feedstocks and additives in 23 added-value composts as a growing media component on Pythium irregulare suppressivity.

Alternative materials with added-value functions, such as phytopathogen suppression and biostimulant and/or biofertilising activity, have been proposed as peat substitutes in growing media. The aim of this work was to evaluate the effect of 23 agro-industrial composts as components of growing media for baby-leaf lettuce transplant production and their activity against the plant pathogen Pythium irregulare. The composts were produced by mixing different starting feedstocks-tomato waste, leek waste, olive mill cake and vineyard pruning waste-with different additives (coffee, thyme, lavender and rockrose waste), which were incorporated at the beginning of the maturation phase. The results obtained indicated that the composts were mature enough to be used as growing media. The fresh weight of the lettuce plants grown with the different composts was significantly higher than in plants obtained with peat. Composts with the coffee additive produced higher lettuce fresh weight, while those with thyme yielded a lower fresh weight. Moreover, composts as components of growing media showed significantly higher P. irregulare suppressiveness than peat. The composts with additives produced lower lettuce fresh weight than composts without additives, but showed higher suppressiveness. Composts with additives showed opposite results depending on whether they were exposed to pathogens or not. Composts with additives showed opposite results according to pathogen pressure or not. Out of all the composts studied, the compost with tomato waste and leek waste as the initial feedstock, and lavender as an additive, showed the highest suppressive capacity. After lettuce harvesting, the growing media with composts showed significantly lower concentrations of P. irregulare than peat. Principal Component Analysis (PCA) revealed that the growing media with compost can be grouped together according to the additive type.

Genetic diversity and accession structure in European Cynara cardunculus collections.

Understanding the distribution of genetic variations and accession structures is an important factor for managing genetic resources, but also for using proper germplasm in association map analyses and breeding programs. The globe artichoke is the fourth most important horticultural crop in Europe. Here, we report the results of a molecular analysis of a collection including globe artichoke and leafy cardoon germplasm present in the Italian, French and Spanish gene banks. The aims of this study were to: (i) assess the diversity present in European collections, (ii) determine the population structure, (iii) measure the genetic distance between accessions; (iv) cluster the accessions; (v) properly distinguish accessions present in the different national collections carrying the same name; and (vi) understand the diversity distribution in relation to the gene bank and the geographic origin of the germplasm. A total of 556 individuals grouped into 174 accessions of distinct typologies were analyzed by different types of molecular markers, i.e. dominant (ISSR and AFLP) and co-dominant (SSR). The data of the two crops (globe artichoke and leafy cardoon) were analyzed jointly and separately to compute, among other aims, the gene diversity, heterozygosity (He, Ho), fixation indexes, AMOVA, genetic distance and structure. The findings underline the huge diversity present in the analyzed material, and the existence of alleles that are able to discriminate among accessions. The accessions were clustered not only on the basis of their typology, but also on the basis of the gene bank they come from. Probably, the environmental conditions of the different field gene banks affected germplasm conservation. These outcomes will be useful in plant breeding to select accessions and to fingerprint varieties. Moreover, the results highlight the particular attention that should be paid to the method used to conserve the Cynara cardunculus germplasm and suggest to the preference of using accessions from different gene banks to run an association map.

European cowpea landraces for a more sustainable agriculture system and novel foods.

BACKGROUND: Genetic diversity is fundamental to breeding programs and consequently has an important role in obtaining new varieties. To properly use the genetic diversity present in germplasm collections, a good knowledge of the agro-morphological traits of each accession is needed. The aim of this study was to explore the production capacity of 24 cowpea landraces from southern Europe, through phenotypic characterization and evaluation in three different locations in Greece and Portugal. RESULTS: Most qualitative parameters tested showed a high stability among the three locations. A wide difference was observed among the three locations with respect to number of days to flowering, ranging from 55 to 99 days. Quantitative traits showed a higher genotype × environment than genetic variance component. In general, an inverse relationship between σ2ge /σ2g ratio (where σ2ge is genotype × genotype interaction and σ2g is genotype impact) and heritability value was observed. Principal component analysis was able to group accessions based on their origin. The first two principal components explained 97.52% of variation, being the number of seeds per plant, plant height and seed protein content, the traits which contributed most to variability. CONCLUSION: The results show that sufficient variation exists in different traits within landraces in the studied cowpea germplasm to pursue a breeding program. However, the quantitative traits showed a higher genotype × environment component. © 2017 Society of Chemical Industry.