Triploid flowering pears reduce self-sowing

October 19, 2016

MILLS RIVER, NC - Flowering pear trees are popular additions to landscapes across much of the United States. The attractive ornamentals are favored for their abundance of white flowers, showy fall color, broad pest resistance, striking forms, and ability to thrive in the USDA plant hardiness zones 5 to 8. However, in some areas, flowering pears reseed and naturalize prolifically, creating issues that have caused one variety to be listed by the U.S. Fish and Wildlife Service as a "plant invader" in mid-Atlantic natural areas. "Birds eat the fruits and disperse seeds into nearby areas where it commonly naturalizes in old fields and along highways," explained Thomas Ranney, corresponding author of a study in the August 2016 issue of HortScience. Ranney and coauthors Whitney Phillips, Darren Touchell, and Thomas Eaker studied flowering pear hybrids to investigate options for developing infertile cultivars.

"Development of highly infertile cultivars would be desirable as an alternative to the fertile cultivars currently available," the authors said. "One approach for producing seedless plants is through the development of triploids." Triploids typically are highly infertile due to a reproductive barrier that has three sets of chromosomes. The sets of chromosomes cannot be divided evenly during meiosis, yielding unbalanced segregation of chromosomes. Breeding of triploid plants has been used successfully to develop seedless cultivars of crops such as bananas, watermelons, and some citrus.

The study involved triploid Pyrus hybrids established in a field at the Mountain Horticultural Crops Research and Extension Center in Mills River, North Carolina. Thirteen triploids were selected from the original population based on desirable traits, including heavy flowering, desirable forms, absence of fire blight, and attractive fall color.

The researchers determined female fertility of each triploid by comparing the number of seedlings per flower of a triploid to the most fertile diploid control. Fertility was characterized by evaluating fruit set, seeds per fruit, seed germination, seedlings per flower, and percent relative fertility. Data showed that many triploids displayed a substantial reduction in fertility (as much as 100%). Relative female fertility varied considerably among accessions and ranged from 0.0% to 33.6%. Of the 13 triploids used in this study, five accessions had a relative fertility of <2%.

Flow cytometry was used to determine relative genome sizes and ploidy levels of female parents, seedlings, and seeds (both embryo and endosperm) and to make inferences regarding reproductive pathways. "Analysis of seeds and seedlings from triploid maternal parents showed that they were predominantly abnormal aneuploids, which typically results in seedlings with reduced fitness and fertility," the authors said.

"These results indicate that selection of highly infertile triploid cultivars is a viable approach to reduce or eliminate the self-sowing of flowering pears in the landscape," the authors concluded.
-end-
The complete study and abstract are available on the ASHS HortScience electronic journal web site: http://hortsci.ashspublications.org/content/51/8/968.abstract

Founded in 1903, the American Society for Horticultural Science (ASHS) is the largest organization dedicated to advancing all facets of horticultural research, education, and application. More information at ashs.org

American Society for Horticultural Science

Related Fertility Articles from Brightsurf:

What are your chances of having a second IVF baby after fertility treatment for the first?
As the restrictions on fertility clinics start to be lifted and IVF treatment resumes, research published in Human Reproduction journal offers reassuring news to women who have had to delay their treatment for a second IVF baby because of the coronavirus.

Fertility preservation use among transgender adolescents
Transgender adolescents often seek hormonal intervention to achieve a body consistent with their gender identity and those interventions affect reproductive function.

A new way to assess male fertility
Current tests for male fertility include measuring the concentration and motility of spermatozoa.

Male fertility after chemotherapy: New questions raised
Professor Delb├Ęs, who specializes in reproductive toxicology, conducted a pilot study in collaboration with oncologists and fertility specialists from the McGill University Health Centre (MUHC) on a cohort of 13 patients, all survivors of pediatric leukemia and lymphoma.

Vaping may harm fertility in young women
E-cigarette usage may impair fertility and pregnancy outcomes, according to a mouse study published in the Journal of the Endocrine Society.

Are fertility apps useful?
Researchers at EPFL and Stanford have carried out an analysis of the largest datasets from fertility awareness apps.

Marijuana and fertility: Five things to know
For patients who smoke marijuana and their physicians, 'Five things to know about ... marijuana and fertility' provides useful information for people who may want to conceive.

How could a changing climate affect human fertility?
Human adaptation to climate change may include changes in fertility, according to a new study by an international group of researchers.

Migrants face a trade-off between status and fertility
Researchers from the universities of Helsinki, Turku and Missouri as well as the Family Federation of Finland present the first results from a new, extraordinarily comprehensive population-wide dataset that details the lives of over 160,000 World War II evacuees in terms of integration.

Phthalates may impair fertility in female mice
A phthalate found in many plastic and personal care products may decrease fertility in female mice, a new study found.

Read More: Fertility News and Fertility Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.