DNA profiling with the 20K apple SNP array reveals hybridization and admixture in , , and genebank accessions.

The USDA-ARS National Plant Germplasm System (NPGS) apple collection in Geneva, NY, USA maintains accessions of the primary (Suckow) Borkh. progenitor species (Ledeb.) M.

Minimizing the deleterious effects of endophytes in plant shoot tip cryopreservation.

Plant cryopreservation technologies are used within gene banks for the long-term preservation of vegetatively propagated collections. Surface-sterilized plant tissues grown in the field, greenhouse/screenhouse, growth chamber, or in vitro are the source of shoot tips subjected to vitrification-based cryopreservation methods. Here, we describe the methods used to minimize microbial contamination during the tissue culture initiation process.

Changes in transcript expression patterns as a result of cryoprotectant treatment and liquid nitrogen exposure in Arabidopsis shoot tips.

Transcripts related to abiotic stress, oxidation, and wounding were differentially expressed in Arabidopsis shoot tips in response to cryoprotectant and liquid nitrogen treatment. Cryopreservation methods have been implemented in genebanks as a strategy to back-up plant genetic resource collections that are vegetatively propagated. Cryopreservation is frequently performed using vitrification methods, whereby shoot tips are treated with cryoprotectant solutions, such as Plant Vitrification Solution 2 (PVS2) or Plant Vitrification Solution 3 (PVS3); these solutions remove and/or replace freezable water within the meristem cells.

Chloroplast heterogeneity and historical admixture within the genus Malus.

Unlabelled: •

Premise Of The Study: The genus Malus represents a unique and complex evolutionary context in which to study domestication. Several Malus species have provided novel alleles and traits to the cultivars. The extent of admixture among wild Malus species has not been well described, due in part to limited sampling of individuals within a taxon.

Genetic diversity in Malus ×domestica (Rosaceae) through time in response to domestication.

Unlabelled: •

Premise Of The Study: Patterns of genetic diversity in domesticated plants are affected by geographic region of origin and cultivation, intentional artificial selection, and unintentional genetic bottlenecks. While bottlenecks are mainly associated with the initial domestication process, they can also affect diversity during crop improvement. Here, we investigate the impact of the improvement process on the genetic diversity of domesticated apple in comparison with other perennial and annual fruit crops.