Publications by authors named "Randi A Famula"

Strawberry (Fragaria ananassa) reproduces sexually through seeds and asexually through stolons. The ability to cost-effectively clonally propagate hybrid individuals on a large scale has shaped strawberry breeding and production practices. Despite the technical and economic importance of clonal propagation, little is known about the genetic regulation of runnering in strawberry, apart from the pleiotropic effects of PERPETUAL FLOWERING (PF), a dominant gene introgressed from a wild relative that abolishes temperature-dependent photoperiod sensitivity and incompletely and variably suppresses runnering.

View Article and Find Full Text PDF

Wildtype fruit of cultivated strawberry (  [Formula: see text]  ) are typically soft and highly perishable when fully ripe. The development of firm-fruited cultivars by phenotypic selection has greatly increased shelf-life, decreased postharvest perishability, and driven the expansion of strawberry production worldwide. Hypotheses for the firm-fruited phenotype include mutations affecting the expression of genes encoding polygalacturonases (PGs) that soften fruit by degrading cell wall pectins.

View Article and Find Full Text PDF

Heterosis was the catalyst for the domestication of cultivated strawberry (Fragaria × ananassa), an interspecific hybrid species that originated in the 1700s. The hybrid origin was discovered because the phenotypes of spontaneous hybrids transgressed those of their parent species. The transgressions included fruit yield increases and other genetic gains in the twentieth century that sparked the global expansion of strawberry production.

View Article and Find Full Text PDF

f. sp. () race 1 is avirulent on cultivars with the dominant resistance gene , while race 2 is virulent on -resistant cultivars.

View Article and Find Full Text PDF

Two decades have passed since the strawberry () disease caused by , a necrotrophic soilborne fungal pathogen, began surfacing in California, Florida, and elsewhere. This disease has since become one of the most common causes of plant death and yield losses in strawberry. The problem emerged and expanded in the wake of the global phase-out of soil fumigation with methyl bromide and appears to have been aggravated by an increase in climate change-associated abiotic stresses.

View Article and Find Full Text PDF

Verticillium wilt (VW), a devastating vascular wilt disease of strawberry (Fragaria ananassa), has caused economic losses for nearly a century. This disease is caused by the soil-borne pathogen Verticillium dahliae, which occurs nearly worldwide and causes disease in numerous agriculturally important plants. The development of VW-resistant cultivars is critically important for the sustainability of strawberry production.

View Article and Find Full Text PDF

Genomic prediction in breeding populations containing hundreds to thousands of parents and seedlings is prohibitively expensive with current high-density genetic marker platforms designed for strawberry. We developed mid-density panels of molecular inversion probes (MIPs) to be deployed with the "DArTag" marker platform to provide a low-cost, high-throughput genotyping solution for strawberry genomic prediction. In total, 7742 target single nucleotide polymorphism (SNP) regions were used to generate MIP assays that were tested with a screening panel of 376 octoploid Fragaria accessions.

View Article and Find Full Text PDF

The development of strawberry (Fragaria × ananassa Duchesne ex Rozier) cultivars resistant to Phytophthora crown rot (PhCR), a devastating disease caused by the soil-borne pathogen Phytophthora cactorum (Lebert & Cohn) J. Schröt., has been challenging partly because the resistance phenotypes are quantitative and only moderately heritable.

View Article and Find Full Text PDF
Article Synopsis
  • Several resistance genes against Fusarium wilt in strawberries were identified and mapped, allowing for the development of resistant cultivars through marker-assisted selection.
  • The Fusarium oxysporum f. sp. fragariae pathogen significantly threatens strawberry production, causing severe wilting and plant death in susceptible varieties.
  • Resistance to multiple races of the pathogen is widespread in strawberry populations, and further genetic studies are planned to identify the specific genes responsible for this resistance to prevent potential outbreaks.
View Article and Find Full Text PDF

Cultivated strawberry (Fragaria × ananassa) is one of our youngest domesticates, originating in early eighteenth-century Europe from spontaneous hybrids between wild allo-octoploid species (Fragaria chiloensis and Fragaria virginiana). The improvement of horticultural traits by 300 years of breeding has enabled the global expansion of strawberry production. Here, we describe the genomic history of strawberry domestication from the earliest hybrids to modern cultivars.

View Article and Find Full Text PDF

Verticillium wilt, a soil-borne disease caused by the fungal pathogen Verticillium dahliae, threatens strawberry (Fragaria × ananassa) production worldwide. The development of resistant cultivars has been a persistent challenge, in part because the genetics of resistance is complex. The heritability of resistance and genetic gains in breeding for resistance to this pathogen have not been well documented.

View Article and Find Full Text PDF

Background: Shape is a critical element of the visual appeal of strawberry fruit and is influenced by both genetic and non-genetic determinants. Current fruit phenotyping approaches for external characteristics in strawberry often rely on the human eye to make categorical assessments. However, fruit shape is an inherently multi-dimensional, continuously variable trait and not adequately described by a single categorical or quantitative feature.

View Article and Find Full Text PDF

Conifers are the dominant plant species throughout the high latitude boreal forests as well as some lower latitude temperate forests of North America, Europe, and Asia. As such, they play an integral economic and ecological role across much of the world. This study focused on the characterization of needle transcriptomes from four ecologically important and understudied North American white pines within the subgenus The populations of many species are challenged by native and introduced pathogens, native insects, and abiotic factors.

View Article and Find Full Text PDF

Sugar pine (Pinus lambertiana Douglas) is within the subgenus Strobus with an estimated genome size of 31 Gbp. Transcriptomic resources are of particular interest in conifers due to the challenges presented in their megagenomes for gene identification. In this study, we present the first comprehensive survey of the P.

View Article and Find Full Text PDF
Article Synopsis
  • The Persian walnut is a key nut species with high nutritional value due to its polyphenolic compounds, but its full biosynthetic pathways remain largely unexplored.
  • Researchers sequenced the genome of the 'Chandler' cultivar, creating a 667-Mbp assembly revealing 32,498 gene models, including two polyphenol oxidase genes (JrPPO1 and JrPPO2).
  • The genome provides vital insights into polyphenol synthesis and serves as a tool for enhancing breeding and understanding complex traits in J. regia.
View Article and Find Full Text PDF