The University of California Riverside has entered into a US$2.25m partnership with Spain-based Eurosemillas to help the university bring to market the most promising and advanced avocado scions and rootstocks in its collection.

If successful, these varieties would meet diverse regional growing requirements, exhibit better post-harvest characteristics, increase yields, provide resistance against disease, and expand consumer market diversity, UC Riverside said.

“Eurosemillas has successfully commercialized citrus varieties developed at UC Riverside in the past. They have the global network and expertise to do the same with the next generation of avocados,” said Brian Suh, director of technology commercialization in the Office of Technology Partnerships at UC Riverside.

Suh has worked with a team on this initiative for the past four years.

Eurosemillas will obtain access to a small subset of the overall university avocado variety and rootstock collection for evaluation and testing on various continents to see if they perform as well as they do in California.

At the same time, the company will forge partnerships for commercialization that could lead to global market penetration of some of these selections.

“After 31 years of working with UC on many other crops, we are delighted to partner with UCR again in a new product like avocado,” said Javier Cano Pecci, chief executive and development officer of Eurosemillas.

“The avocado market is growing and is currently dominated by the Hass variety. This is a great opportunity for growers, marketers, retailers, and consumers to have options and diversify to include better avocado varieties and rootstocks adapted to their regions.”

Long history of avocado breeding

UC Riverside’s 70-year old avocado breeding programs house one of the most elite germplasm collections of scion and rootstock breeding material in the world.

The University of California has partnered with California avocado growers since the inception of the industry a century ago and has had several plant breeders developing new varieties and rootstocks for the industry.

Bob Bergh headed the variety improvement program for nearly 40 years, which released among other varieties, the ‘Lamb Hass’ and ‘GEM.’

This program is under the leadership of Mary Lu Arpaia, an extension horticulturist. The goal of the variety breeding program is to develop trees with high eating and market quality while increasing yield efficiency.

Arpaia said for the California industry to remain viable, growers must have new varieties that yield more than Hass, are more tolerant to environmental stress, and can be produced reliably under high-density planting systems.

“I am delighted by this partnership with Eurosemillas since it will help UC take this vision for the future toward reality,” Arpaia said.

The variety improvement program has four selections being readied for release that can augment the ‘Hass’ variety in terms of seasonality and have potential for expanded environmental adaptation within California.

The program - which has been historically funded by the California industry through the California Avocado Commission - is selecting rootstocks that can resist Phytophthora root rot, the most common avocado disease worldwide, as well as salinity, drought, and heat, all of which are expected to become worse as the climate warms.

In collaboration with the California Avocado Commission, five UC Riverside advanced rootstocks exhibiting resistance to these major challenges are being evaluated by growers throughout California.

“This partnership with Eurosemillas will allow us to test our five advanced rootstocks in combination with ‘Hass’ and local scions in other countries to determine their potential outside California,” Manosalva said.