Search Results

You are looking at 1 - 10 of 113 items for :

Clear All

values greater than 50% are shown. All samples were found to be tetraploids except sample E11, which is an octoploid; M = ‘Meyer’, ED = ‘Emerald’, D = ‘Diamond’, Z = ‘Zeon’, E = ‘Empire’, J = ‘JaMur’. Flow cytometry. Zoysiagrass samples were processed and

Free access

= 6 x = 72) cytotype of Z. mauritiana , was reported recently ( Wang et al., 2018 , 2019 ). The average and median values (410.72 Mb and 417.45 Mb, respectively) we found for the octoploid (2 n = 8 x = 96) are closer to the genome size estimate of

Open Access

The octoploid cultivated strawberry, Fragaria × ananassa Duch. (2 n = 8 x = 56), was derived from accidental hybridization between two American octoploid species, F . virginiana and F . chiloensis , during the early to mid-1700s ( Darrow

Free access
Authors: , , and

granatum ( Shao et al., 2003 ), and Rosa rugosa ( Allum et al., 2007 ). In our study, we found more chimeras were produced than pure chromosome-doubled plants, and obtained a chimera plantlet simultaneously composed of diploid, tetraploid, and octoploid

Free access

The cultivated strawberry was originally derived from the accidental hybridization of two wild, octoploid species, Fragaria chiloensis and Fragaria virginiana ( Darrow, 1966 ). The resulting octoploid hybrid, Fragaria × ananassa , is the basis

Free access

Fragaria ×ananassa, the cultivated octoploid strawberry, is an intensively cultivated fruit crop in which relatively small variations in disease susceptibility and flowering habit can have significant economic impacts. In order to facilitate future studies of the molecular mechansisms governing these characters, we have initiated studies to identify and sequence the strawberry homologs of a number of important genes known to be critical to pathogenesis response and photoperiodism in model systems such as arabidopsis, rice, and tomato. Using the primary Florida cultivar Strawberry Festival, we have employed a variety of techniques to identify such genes, including EST sequencing of a salicylate-induced cDNA library, PCR with degenerate primers, and colony hybridization. Possible homologs of the targeted genes and their relationships to similar genes in other species are presented. These results will form the basis of future studies of gene expression and evolutionary relationships among the Rosaceae and other species.

Free access
Author:

Abstract

A synthetic octoploid was derived from 2 diploid and 1 tetraploid species of Fragaria L. The clone is recommended for use in strawberry breeding as it contains germplasm not previously available at the octoploid level.

Open Access
Author:

Abstract

A synthetic octoploid has been developed from a tetraploid hybrid of Fragaria moschata Duch. (2n = 42) and F. nubicola Duch. (2n = 14). The clone is recommended for use in strawberry breeding as it contains germ plasm not previously available at the octoploid level.

Open Access

Fragaria species from the center of diversity have not been integrated into octoploid commercial strawberry cultivars because of ploidy level differences. Even though traits such as disease resistance, enhanced flavor, cold hardiness, and vigor are known to exist in the diploid, tetraploid, and hexaploid species, they cannot be easily used for breeding. The synthetic octoploid method circumvented introgression difficulties by combining lower ploidy species and doubling to the octoploid level. Although easily crossed to cultivars, the use of synthetic octoploids has been minimal as it has been extremely difficult to create them. By working to improve bottlenecks of the original system, improved methodology has been developed and 170 synthetic octoploids have been produced. This represents more than a 100-fold increase in efficiency. The following factors played a major role in improving the system: wide germplasm base; use of F. vesca as a common genome; embryo rescue; 5% colchicine applied in vitro by dropper method for 24 hours followed by a quick rinse and continuous light in a 18C growth chamber. F. vesca, F. nilgerrensis, F. nubicola, F. viridis, F. orientalis, and F. moschata have been incorporated into synthetic octoploids in this study.

Free access

Abstract

A haploid (2n = 28) derived from Fragaria × ananassa Duch. cv. Tioga (2n = 56) was obtained after pollination with Potentilla anserina L. The sublethality of the true hybrids is an excellent screen for exposing the polyhaploids that might be difficult to detect in normal octoploid populations.

Open Access