UC Riverside releases new citrus variety

August 04, 2009

RIVERSIDE, Calif. - Citrus researchers at the University of California, Riverside have released a new mandarin (or tangerine) for commercial production. Named 'DaisySL' for Daisy seedless, the new fruit is finely textured and juicy, with a rich, sweet and distinctive flavor when mature. Its rind is smooth and thin, and bears a deep orange color.

"We are extremely enthusiastic about this fruit which distinguishes itself by being very low-seeded and moderately easy to peel," said Mikeal Roose, a professor of genetics in the Department of Botany and Plant Sciences, who developed 'DaisySL' along with staff scientist Timothy Williams. "In Riverside, California, 'DaisySL' matures in mid-December and holds its fruit quality characteristics into February. Early January to early February is the best time to pick this fruit from the tree."

Williams, who supervised the planting of the trees and performs evaluations and selections of promising varieties, noted that 'DaisySL' had the right characteristics he and Roose were looking for in a new variety: beautiful appearance, exceptional flavor and hardly any seeds.

"'DaisySL' is similar to many other selections we evaluated, but it stood out from the rest, and we knew right off that we had something special," Williams said.

Still, he and Roose continued their evaluations of 'DaisySL' and waited eight years from when they saw the first fruiting on a single tree to announce it as a new variety ready for UC Riverside to release.

A new variety is born

Roose and Williams developed DaisySL from an irradiated bud of the seedy diploid mandarin cultivar 'Daisy,' a mid-season maturing variety that is a hybrid of the mandarins Fortune and Fremont. As is the case with most citrus trees, 'DaisySL' was asexually reproduced by grafting of budwood onto rootstocks.

After starting a mutation breeding project like the one that led to 'DaisySL,' it usually takes citrus breeders four to five years to identify a promising selection with the desired traits on an individual tree. Breeders then establish many trees of the selection and subject them to trials in differing climatic areas to evaluate fruit quality, tree growth and production - a process that takes at least three additional years of fruiting. Once UCR breeders were convinced of the potential of 'DaisySL,' the university released the variety, more than ten years after the first tree was produced.

'DaisySL' availability

In September 2009 UCR will release 'DaisySL' for propagation by California citrus nurseries that have purchased licenses to propagate and sell the variety in the state. The citrus breeding project that developed 'DaisySL' is partly funded by California citrus growers and nurseries through the Citrus Research Board and California Citrus Nursery Board. Distribution of 'DaisySL' is limited to California for three years after release.

Roose and Williams estimate it will be five years before the first 'DaisySL' fruit arrives in grocery stores. They explained it takes one or two years for the industry to make enough budwood for commercial budding, another year to produce a tree, and an additional two to three years to produce the first fruit.

UCR's Office of Technology Commercialization filed for a U.S. patent for 'DaisySL' in June 2009.

Fruit details

The 'DaisySL' fruit averages 2.7 inches (68 mm) in diameter and about 2.4 inches (60 mm) in height. Each fruit has 10-11 segments and a semi-solid axis of medium size at maturity. The fruit is juicy, averaging 47 percent juice, and weighs 135 grams on average. It averages 2.2 seeds per fruit in mixed plantings with other citrus varieties (in more uniformly varietal commercial plantings, a lower seed content is expected).

A centennial tradition

UCR has a long tradition in citrus research. In 1907, the University of California established the Citrus Experiment Station at the foot of Mount Rubidoux in Riverside to support Southern California's growing citrus industry with scientific data to improve production. In 1917, the station moved to what is now the A. Gary Anderson School of Management. The station became the foundation for the UCR campus, which opened in 1954.

Now known as the Citrus Research Center-Agricultural Experiment Station, the work of the center has grown to include all aspects of agricultural production in arid and semi-arid subtropical lands. Research on citrus production and development of new varieties remains a major focus of UCR agricultural research.
-end-
UCR is home also to the University of California Citrus Variety Collection, consisting of two trees each of more than 1000 different citrus types. Used extensively to solve citrus disease problems and improve commercial varieties, the collection is one of the world's premier citrus germplasm collections.

The University of California, Riverside is a doctoral research university, a living laboratory for groundbreaking exploration of issues critical to Inland Southern California, the state and communities around the world. Reflecting California's diverse culture, UCR's enrollment of about 17,000 is expected to grow to 21,000 students by 2020. The campus is planning a medical school and has reached the heart of the Coachella Valley by way of the UCR Palm Desert Graduate Center. The campus has an annual statewide economic impact of more than $1 billion. To learn more, visit www.ucr.edu or call (951) UCR-NEWS.

University of California - Riverside

Related Citrus Articles from Brightsurf:

New tools in the fight against lethal citrus disease
Scientists are closer to gaining the upper hand on Huanglongbing, a disease that has wiped out citrus orchards across the globe.

Infected insects may warn of impending citrus disease a year in advance
Despite the first appearance of citrus greening disease in Florida in 2005, the bacterium wasn't found in Texas until 2011, when scientists detected it in the psyllids.

Harnessing psyllid peptides to fight citrus greening disease
BTI, USDA and UW scientists have identified peptides in the Asian citrus psyllid, an insect that spreads the bacterium that causes citrus greening disease (huanglongbing, HLB).

New technique has potential to protect oranges from citrus greening
Citrus greening, also called Huanglongbing (HLB), is devastating the citrus industry.

Eliminating viruses in our food with cranberries and citrus fruit
Fresh produce is a major vehicle for noroviruses, a group of viruses that are the most common cause of gastroenteritis in developed countries.

First study to compare citrus varieties with combination of metabolomics and microbiome
Citrus greening disease, or Huanglongbing (HLB), is deadly, incurable, and the most significant threat to the citrus industry.

University of Florida scientists advance citrus greening research efforts
To facilitate the scientific community's ability to use L. crescens in citrus greening research, University of Florida Department of Plant Pathology scientists have published an article in Phytopathology that outlines, step-by-step, highly reproducible and detailed protocols that they have standardized for culturing L. crescens.

Researchers grow citrus disease bacteria in the lab
Being able to grow the elusive and poorly understood bacterium, Candidatus Liberibacter asiaticus (CLas), will make it easier for researchers to find treatments for the disease that has destroyed millions of acres of orange, grapefruit and lemon groves around the world and has devastated the citrus industry in Florida.

Potential treatments for citrus greening
Finding a treatment for a devastating, incurable citrus disease was personal for Sharon Long and Melanie Barnett.

Greening devastates the citrus industry -- new research offers a solution
Citrus Huanglongbing (HLB), also known as greening, is one of the most serious citrus plant diseases in the world.

Read More: Citrus News and Citrus 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.