ABSTRACT
Floral morphology and pigmentation are both charismatic and economically relevant traits associated with cultivated sunflower (Helianthus annuus L.). Recent work has linked floral morphology and pigmentation to pollinator efficiency and seed yield. Understanding the genetic architecture of such traits is essential for crop improvement, and gives insight into the role of genetic constraints in shaping floral diversity. A diversity panel of 288 sunflower genotypes was phenotyped for a variety of morphological, phenological, and color traits in both a greenhouse and a field setting. Association mapping was performed using 5788 SNP markers using a mixed linear model approach. Several dozen markers across 10 linkage groups were significantly associated with variation in morphological and color trait variation. Substantial trait plasticity was observed between greenhouse and field phenotyping, and associations differed between environments. Color traits mapped more strongly than morphology in both settings, with markers together explaining 16% of petal carotenoid content in the greenhouse, and 17% and 24% of variation in disc anthocyanin presence in the field and greenhouse, respectively. Morphological traits like disc size mapped more strongly in the field, with markers together explaining up to 19% of disc size variation. Loci identified here through association mapping within cultivated germplasm differ from those identified through biparental crosses between modern cultivated sunflower and either its wild progenitor or domesticated landraces. Several loci lie within genomic regions involved in domestication. Differences between phenotype expression under greenhouse and field conditions highlight the importance of plasticity in determining floral morphology and pigmentation.
Subject(s)
Chromosome Mapping , Flowers/genetics , Genome, Plant , Genome-Wide Association Study , Helianthus/genetics , Quantitative Trait, Heritable , Chromosome Mapping/methods , Genetic Linkage , Helianthus/classification , Phenotype , Phylogeny , Pigmentation , Polymorphism, Single Nucleotide , Quantitative Trait LociABSTRACT
Viruses impose an immense burden on human health. With the goal of treating and preventing viral infections, researchers have carried out genetic screens to improve our understanding of viral dependencies and identify potential anti-viral strategies. The emergence of CRISPR genetic screening tools has facilitated this effort by enabling host-virus screens to be undertaken in a more versatile and fidelitous manner than previously possible. Here we review the growing number of CRISPR screens which continue to increase our understanding of host-virus interactions.