Genetic dissection of nitrogen induced changes in the shoot and root biomass of spinach

Improvement of crop production in controlled environment agriculture through breeding

Controlled environment agriculture (CEA) represents one of the fastest-growing sectors of horticulture. Production in controlled environments ranges from highly controlled indoor environments with 100% artificial lighting (vertical farms or plant factories) to high-tech greenhouses with or without supplemental lighting, to simpler greenhouses and high tunnels. Although food production occurs in the soil inside high tunnels, most CEA operations use various hydroponic systems to meet crop irrigation and fertility needs. The expansion of CEA offers promise as a tool for increasing food production in and near urban systems as these systems do not rely on arable agricultural land. In addition, CEA offers resilience to climate instability by growing inside protective structures. Products harvested from CEA systems tend to be of high quality, both internal and external, and are sought after by consumers. Currently, CEA producers rely on cultivars bred for production in open-field agriculture. Because of high energy and other production costs in CEA, only a limited number of food crops have proven themselves to be profitable to produce. One factor contributing to this situation may be a lack of optimized cultivars. Indoor growing operations offer opportunities for breeding cultivars that are ideal for these systems. To facilitate breeding these specialized cultivars, a wide range of tools are available for plant breeders to help speed this process and increase its efficiency. This review aims to cover breeding opportunities and needs for a wide range of horticultural crops either already being produced in CEA systems or with potential for CEA production. It also reviews many of the tools available to breeders including genomics-informed breeding, marker-assisted selection, precision breeding, high-throughput phenotyping, and potential sources of germplasm suitable for CEA breeding. The availability of published genomes and trait-linked molecular markers should enable rapid progress in the breeding of CEA-specific food crops that will help drive the growth of this industry.

Unraveling genetic mysteries: A comprehensive review of GWAS and DNA insights in animal and plant pathosystems

DNA serves as the carrier of genetic information, with sequence variations playing a pivotal role in defining hereditary traits. Genome-Wide Association Studies (GWAS) facilitate the investigation of the links between genetic variations and phenotypes, significantly influencing biological research, particularly in animal and plant pathology. By identifying genetic markers associated with specific traits or diseases, GWAS enhances our understanding of host-pathogen interactions and improves disease-resistant breeding strategies. It has been vital in revealing the genetic basis of disease resistance, pinpointing key genes and DNA loci, which enrich genetic resources for breeding programs and deepen our knowledge of disease resistance mechanisms at the DNA level. Additionally, GWAS contributes to pathogen population genetics, facilitating a thorough exploration of pathogen virulence. Integrating GWAS with marker-assisted selection enhances breeding efficiency and precision in selecting for disease-resistant traits. While previous research has largely focused on host genetics, the genetic variation of pathogens is equally significant. Notably, reports integrating animal and plant pathosystems are still lacking. Given the importance of these systems, this review summarizes key advancements in this field, addresses current challenges, and proposes future directions, thereby offering a vital reference for ongoing research.

Temporal phenotypic variation of spinach root traits and its relation to shoot performance

The root system is important for the growth and development of spinach. To reveal the temporal variability of the spinach root system, root traits of 40 spinach accessions were measured at three imaging times (20, 30, and 43 days after transplanting) in this study using a non-destructive and non-invasive root analysis system. Results showed that five root traits were reliably measured by this system (RootViz FS), and two of which were highly correlated with manually measured traits. Root traits had higher variations than shoot traits among spinach accessions, and the trait of mean growth rate of total root length had the largest coefficients of variation across the three imaging times. During the early stage, only tap root length was weakly correlated with shoot traits (plant height, leaf width, and object area (equivalent to plant surface area)), whereas in the third imaging, root fresh weight, total root length, and root area were strongly correlated with shoot biomass-related traits. Five root traits (total root length, tap root length, total root area, root tissue density, and maximal root width) showed high variations with coefficients of variation values (CV ≥ 0.3, except maximal root width) and high heritability (H2 > 0.6) among the three stages. The 40 spinach accessions were classified into five subgroups with different growth dynamics of the primary and lateral roots by cluster analysis. Our results demonstrated the potential of in-situ phenotyping to assess dynamic root growth in spinach and provide new perspectives for biomass breeding based on root system ideotypes.