In this installment of the UF/IFAS TREC’s Research Report, you get to learn about the bounty in Dr. Geoffrey Meru’s vegetable breeding and genomics lab. The overarching goal of Dr. Meru’s program is the development of high-yielding subtropical and tropical vegetable varieties with acceptable resistance / tolerance to abiotic and biotic stresses using contemporary and traditional technologies.

Creating high-yielding tropical vegetables, conventionally

Cucurbits- such as squash, cucumber and watermelon- are economically important vegetable crops in Florida. Like most plants in Florida, there are several biotic stresses which can impact cucurbits. Some of those biotic stresses include powdery mildew, downy mildew, phytophthora capsici, anthracnose, aphid transferred viruses, and whitefly transferred viruses and disorders. Developing cucurbit varieties resistant to such biotic stresses through conventional methods can be an arduous and resource intensive process. First, researchers must identify resistant sources from a vast germplasm collection, a process likened to “searching for a needle in a haystack”. The resistant sources are typically found in wild crop relatives. Once resistant sources are identified, the beneficial traits must be transferred through breeding and selection, thus creating elite cultivars. This labor intensive process has traditionally taken up to 15 years.

Creating high-yielding tropical vegetables, contemporary

With the aid of genetics and genomics tools, this process has been accelerated. By leveraging advances in sequencing technologies and bioinformatics, the vegetable breeding and genomics lab has developed a suite of breeding tools for efficient selection of suitable cucurbit varieties. Current successes include the application of marker-assisted selection to advance resistance to phytophthora crown rot and aphid transmitted viruses, such as zucchini yellow mosaic virus and papaya ringspot virus, respectively. The team of researchers also deploy genomic selection methodologies to develop cucurbit varieties with resistance to powdery mildew. Overall, the application of these tools has accelerated the breeding process and shortened the resistance variety development process to roughly 6-8 years.

Developing superior calabaza varieties

Calabaza squash is a popular delicacy in Florida and the Caribbean. Its flesh is rich in nutrients including vitamin A and C and beneficial phenolic compounds. Researchers at TREC are developing hybrids of calabaza, a tropical vegetable, that combine high yield with superior flesh quality and rich flavor. Three precommercial hybrids (UFTP8, UFTP32 and UFTP80) have done well in field trials across the southeastern US and Puerto Rico. Stay tuned to this Research Report for more an update on these improved calabaza varieties.

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