WASHINGTON – Climate change creates hotter weather and drier seasons – and new challenges for farmers. Such excessive heat damages seed quality, creating problems for seed producers and growers to establish uniform and productive crops. To help farmers address this challenge, the Foundation for Food & Agriculture Research (FFAR) is awarding a $1.1 million grant through the Crops of the Future Collaborative to researchers at the University of California (UC), Davis and the University of Florida to identify genes that boost tolerance for high temperatures and improve seed quality.
The seeds that farmers plant are grown by seed producers. These producers plant specific genetically defined parents and often hybridize them to produce seeds with consistent genetic properties and high germination potential. Depending upon the crop, the seeds or fruits are then harvested using specialized equipment to extract the seeds for processing, packaging and sale. Seed quality also is affected by the environmental conditions that are present during their production, from pollination to packaging.
“We often think about enhancing climate resilience in crops as heat- and drought-proofing plants; however, climate change also affects seeds,” said Dr. Jeff Rosichan, director of the Crops of the Future Collaborative. “If the plant is taxed by climate impacts, the seeds produced by the plant similarly suffer. This research hopes to increase productivity by improving seed quality. Although the research is being conducted in tomato, we are looking for solutions that will translate to other important crops plants.”
Temperatures and other climate stressors experienced by mother plants can result in seeds with variable quality, causing some to thrive and others to fail. Yet, farmers count on consistent seed quality to produce a plentiful harvest and, ultimately, income.
In tomatoes, a $1.67 billion industry, for example, temperatures exceeding 37°C (98.6°F) can reduce pollen viability and subsequent fruit and seed production. This grant is addressing these issues by exploring three primary research objectives. A UC Davis research team is focusing on seed physiology during development in relation to environmental conditions and fruit ripening. The University of Florida Institute of Food and Agricultural Sciences team is investigating how temperature affects tomato fruit development. A third team at UC Davis is examining the effect of temperature on pollen viability and pollination of tomato plants and potential contributions from stress-tolerant, wild species relatives. Knowledge gained from this research will enable producers to adjust their practices and adapt to extreme weather. Genes and processes identified can enable breeders to maintain high seed quality in varieties adapted to more stressful environments.
The UC Davis team includes Distinguished Professor Kent Bradford, Assistant Professor Bárbara Blanco-Ulate and Dr. Roger Chetelat (a geneticist and director of the C.M. Rick Tomato Genetics Resource Center) with Dr. Alfred Huo, an assistant professor of plant breeding, leading the University of Florida group.
“Seeds deliver advanced genetics to growers’ fields, and seed quality is critical for achieving the plant populations desired by growers, whether in the field or in the greenhouse,” said Dr. Bradford. “Our project is investigating the genetic and management factors that result in the highest quality seeds while also expanding the environmental conditions under which the crop will perform well.”
“We are still discovering how the maternal environment impacts seed yield and quality. This project will shed light on how the fruit (maternal tissues) and the seeds (offspring) communicate during their growth and development, and provide key information on how temperature affects these interactions,” explained Dr. Blanco-Ulate. “With this information, we will be able to develop new strategies or genotypes to improve seed quality in tomato and possibly expand this knowledge to other crops.”
“Crop wild relatives provide a potential source of genes for improved resilience to environmental stress. We will use novel breeding lines that incorporate defined genetic material from a wild tomato relative to identify genetic regions underlying pollen thermotolerance and seed vigor,” said Dr. Chetelat.
“Seed development is tightly controlled by genetic factors and environmental cues,” remarked Dr. Huo. “Small RNAs, a type of short nucleotide sequences, are responsive to environments experienced by the mother plants to regulate plant development and growth. We will examine the role of some small RNAs in controlling tomato seed development, and the research findings can be applied to different crops since these small RNAs are highly conserved across plant species.
In addition to enhancing seed quality in tomatoes, the researchers aim to expand the benefits of their findings to other crops, including the possibility of specifically influencing plant reproductive development.
Results from this research will benefit farmers, fresh market and processing tomatoes producers as well as seed companies. A consistent supply of high-quality seeds is critical for maintaining high yields, which is vital for farmers and their bottom lines. Producers of fresh market and processing tomatoes will have higher quality seeds for establishing their crops. Seed companies benefit by better understanding how crop genetics and environmental conditions interact to influence seed quality.
