Desperately Seeking Seedless

Citrus Nursery Source: Desperately Seeking Seedless

In spite of citrus greening and canker being the focus of most current citrus research in Florida, work to develop resistance to these two diseases has been possible only for a few years due to regulatory issues. On the other hand, efforts to produce seedless scion varieties have been ongoing for decades, and products of those efforts have just become available. Over the years, a number of important citrus scion varieties including Minneola (1930), Sunburst (1979), and Fallglo (1987) have been developed and released from the USDA citrus breeding program in Florida. These varieties have had significant impact on fresh fruit trade in Florida as well as other citrus producing regions. However, a common fault shared by each of these important varieties is that they are seedy; whereas in the current market place, seedless citrus fruit is highly desired and can command higher prices than does seedy fruit.

Two new seedless citrus scion varieties, US Seedless Pineapple and US Early Pride, generated by our program were officially released in 2009. Irradiation of seeds was used to induce the seedless character in Pineapple sweet orange (an important midseason processing orange) resulting in US Seedless Pineapple.

Irradiation of budwood was used to induce the seedless character in Fallglo (an important early season mandarin in Florida) resulting in US Early Pride. Results of extensive testing indicate Seedless Pineapple and Early Pride are essentially identical to their seedy progenitors except for the absence of seeds. Seedlessness is a desirable trait in citrus fruit and having seedless variants of otherwise high-quality, established cultivars is of value to the citrus industry.

Seedless Pineapple budwood is available to the public from the Florida Department of Agriculture and Consumer Services Division of Plant Industry Budwood program Chiefland. Early Pride is being considered for patent protection based on requests from the Florida, California, Arizona, and Texas citrus industries. US Early Pride trees are available through an agreement between the USDA-ARS and the New Varieties Development & Management Corp.

It’s In The Genes

The utility of producing seedless variants of standard citrus scion varieties, as demonstrated with Seedless Pineapple and Early Pride, has caused us to devote considerable effort to irradiation of standard seedy scion varieties as well as seedy, but otherwise promising new hybrids in our breeding program. We currently have about 2,000 grafted trees produced from irradiated budwood of several selections in the field in an effort to identify seedless variants. Fruit produced from the irradiated material is evaluated for the presence of seeds. When low-seeded or seedless variants are identified, they are propagated for further evaluation, a process that requires several years.

Handle On Hybrids

Another approach used in our effort to generate new, valuable citrus varieties is to produce hybrids using standard but seedy cultivars as the female (fruit producing) parent in combination with Seedless Kishu, a citrus variety that is naturally seedless, as the male (pollen) parent. Our hypothesis is by using Seedless Kishu as the pollen parent, we should be able to generate at least some hybrids that produce seedless fruit. We are eagerly awaiting production of fruit by these hybrids so we may determine if any of them are seedless. As with all citrus hybrids, these seedling trees must overcome juvenility before they begin to flower and produce fruit, a process that can take numerous years. In an effort to reduce the length of the juvenile phase and thereby shorten the time to fruit production, we have been growing our seedless Kishu hybrids in the greenhouse and pruning them to a single stem, a technique that has been reported to reduce the length of the juvenile phase.

Continued Development

Regardless of techniques used, development of new citrus varieties is an inherently lengthy process, typically requiring decades from creation of new germplasm, thorough evaluation, and eventual release. Objectives that seem important today may be insignificant in five, 10, or 50 years. The need to develop citrus varieties with resistance to citrus canker and citrus greening were not apparent until just recently, and in fact, efforts to produce new varieties resistant to these diseases were not previously possible. Developing varieties with resistance to canker and greening by utilizing the most advanced technologies available has become the focus of our most recent efforts and already progress has been made. It is virtually certain sustainable solutions to these two diseases will become available. When they do, there will still be the need for seedless, high-quality scion varieties to ensure the U.S. citrus industry maintains a competitive advantage. The USDA citrus improvement program is well positioned to continue to contribute such varieties.

Leave a Reply

Featured Stories
Citrus
August 23, 2017
Varroa Mite Researchers Talk High Infestations in Bee Colonies
In 2016, The New York State Beekeeper Tech Team (which is attached to Cornell University’s Dyce Lab Beekeeping Resources) found that Read More
Ed Pines citrus grower
Citrus Achievement Award
August 23, 2017
Citrus Achievement Award Winner Knows How to Block out What’s Bugging Him
Growing citrus indoors can help protect it from the citrus psyllid and the deadly disease it vectors. Read More
Citrus
August 23, 2017
Advice From the FDA on How Growers Can Keep Their Produce Safe
Want tips that will keep your operation on the right side of the FDA when it comes to food safety? American Vegetable Grower® decided the best advice would come directly from the FDA itself.  Read More
More Vegetables
August 23, 2017
20 Pepper Varieties You Need to Know
Leading seed breeders and distributors highlight some of the latest pepper varieties available. Read More
Assorted vegetables
Crop Protection
August 23, 2017
New Biological Fungicide Approved for Fruit and Vegetable Crops
Howler fungicide, developed by AgBiome, receives EPA registration for high-value, specialty crops. Read More
haskap berries
GenNext Growers
August 22, 2017
Top Alternative Crops GenNext Growers Should Consider
Now is a good time for you to think about what new selections might pay off. Read More
Insect Control
August 22, 2017
Stink Bug Threatens High-Dollar Crops in California
While populations are low, it appears invasive pest has recently stumbled upon the state’s peaches and almonds. Read More
Lemon tree in Florida full of fruit
Grapefruit & Specialty
August 22, 2017
More Florida Citrus Producers Pondering the Lemon Pledge
Local farmers are sweet on the prospect of growing the acid fruit. Read More
Berries
August 22, 2017
Columnist Wins Prestigious Plant Breeder Award
John Clark, who writes a column for American Fruit Grower® and Western Fruit Grower® magazines, is honored with National Plant Breeders Association Impact Award. Read More
Apple Grower of the Year
August 22, 2017
U.S. Apple Association Hosts Annual Apple Outlook Conference in Chicago
American Fruit Grower® and Western Fruit Grower® magazine’s 2017 Apple Grower of the Year will be officially presented on Thursday, Aug. 24, during the first day of the conference. Read More
Port Of Miami shipyard
Farm Management
August 21, 2017
NAFTA Renegotiation Long Overdue for Florida Farmers
Specialty crop growers in the Sunshine State seek relief from unfair trade deal. Read More
Alan Jones takes a ride around Jones Potato Farm
Citrus
August 21, 2017
Take Alternative Routes to Find Conventional Farming Solutions [Opinion]
In order to grow, things have to change. Are you ready? Read More
Apples & Pears
August 20, 2017
APHIS Seeks Comments on Risk Removal for Dormant Apple Cuttings
Dormant live cuttings from countries in the European Union must currently go through pest risk assessment. Read More
young Florida citrus grove
Varieties & Rootstocks
August 19, 2017
Pressure Is on to Pick and Plant Citrus Winners
With even more variety selections available, information and communication are keys to success. Read More
honeybees
Citrus
August 19, 2017
More Forage Grants Distributed in Honor of National Honeybee Day
National forage program is scattering seeds from New York to California to celebrate pollinators. Read More
The Latest
Citrus
August 23, 2017
Varroa Mite Researchers Talk High Infest…
In 2016, The New York State Beekeeper Tech Team (which is attached to Cornell University’s Dyce Lab Beekeeping Resources) found that Read More
Citrus Achievement Award
August 23, 2017
Citrus Achievement Award Winner Knows Ho…
Growing citrus indoors can help protect it from the citrus psyllid and the deadly disease it vectors. Read More
Citrus
August 23, 2017
Advice From the FDA on How Growers Can K…
Want tips that will keep your operation on the right side of the FDA when it comes to food safety? American Vegetable Grower® decided the best advice would come directly from the FDA itself.  Read More
More Vegetables
August 23, 2017
20 Pepper Varieties You Need to Know
Leading seed breeders and distributors highlight some of the latest pepper varieties available. Read More
Crop Protection
August 23, 2017
New Biological Fungicide Approved for Fr…
Howler fungicide, developed by AgBiome, receives EPA registration for high-value, specialty crops. Read More
GenNext Growers
August 22, 2017
Top Alternative Crops GenNext Growers Sh…
Now is a good time for you to think about what new selections might pay off. Read More
Insect Control
August 22, 2017
Stink Bug Threatens High-Dollar Crops in…
While populations are low, it appears invasive pest has recently stumbled upon the state’s peaches and almonds. Read More
Grapefruit & Specialty
August 22, 2017
More Florida Citrus Producers Pondering …
Local farmers are sweet on the prospect of growing the acid fruit. Read More
Berries
August 22, 2017
Columnist Wins Prestigious Plant Breeder…
John Clark, who writes a column for American Fruit Grower® and Western Fruit Grower® magazines, is honored with National Plant Breeders Association Impact Award. Read More
Apple Grower of the Year
August 22, 2017
U.S. Apple Association Hosts Annual Appl…
American Fruit Grower® and Western Fruit Grower® magazine’s 2017 Apple Grower of the Year will be officially presented on Thursday, Aug. 24, during the first day of the conference. Read More
Farm Management
August 21, 2017
NAFTA Renegotiation Long Overdue for Flo…
Specialty crop growers in the Sunshine State seek relief from unfair trade deal. Read More
Citrus
August 21, 2017
Take Alternative Routes to Find Conventi…
In order to grow, things have to change. Are you ready? Read More
Apples & Pears
August 20, 2017
APHIS Seeks Comments on Risk Removal for…
Dormant live cuttings from countries in the European Union must currently go through pest risk assessment. Read More
Varieties & Rootstocks
August 19, 2017
Pressure Is on to Pick and Plant Citrus …
With even more variety selections available, information and communication are keys to success. Read More
Citrus
August 19, 2017
More Forage Grants Distributed in Honor …
National forage program is scattering seeds from New York to California to celebrate pollinators. Read More
Citrus
August 18, 2017
Bayer Aims Research Prowess at Defeating…
Company enters collaboration with Citrus Research and Development Foundation to uncover antibacterial and plant defense tools against the disease. Read More
Citrus
August 18, 2017
How Florida Growers are Fine-Tuning Citr…
Some are tweaking nutrition programs to focus on root health along with foliar applications. Read More
Citrus
August 17, 2017
How Wicked Will Winter 2018 Be in the U.…
The 200th edition of the Farmers’ Almanac reveals wide-ranging weather patterns and events that would require everything from shovels to shorts. Read More