MAIZE DOUBLED HAPLOID

The Doubled Haploid Facility is developing new haploid inducing lines for maternal haploid induction in maize. The goal is to increase not only haploid induction rates, but also to add new selectable marker for haploid identification and improved agronomical traits of the inducer lines.

The breeding program started in 2010, when we began to introgress induction ability into Midwest adapted backgrounds, to improve agronomic traits of the so far licensed inducer lines RWS and RWK (ISURF#04065). These lines use the kernel color marker R1-nj as selectable marker. Variable expression of the color marker and suppression in some genetic backgrounds made it necessary to add Pl1 as an additional selectable marker in haploid selection in a second breeding cycle. In the presence of Pl1 the hybrids have dark red roots, whereas the haploid seedlings have uncolored roots. We also added the partial dent sterility (Ga1) to our inducer lines, to allow haploid induction in popcorn backgrounds (ISURF#04099).

Hand selection of haploid seed based on the color marker is very time intensive. A new breeding cycle of haploid inducing lines has the goal to develop a high oil haploid inducing line, to allow machine sorting based on the differences in oil content between haploid and hybrid seed.

PI: Frei U.

Funding: R.F. Baker Center for Plant Breeding
 

SORGHUM

Biofuels are a major contributor to the energy security of the United States, to the economic growth of Iowa and to the reduction of greenhouse gasses emission. The Energy Independence and Security Act (2007) established that 36 billion gallons of biofuels per year had to be produced by 2022. In 2018, 16 billion gallons of ethanol were produced from maize, but maize-based ethanol cannot supply the total demand and it has detrimental implications for food and feed supplies. Therefore, other sources, such as lignocellulosic feedstock, need to be developed.

In 2008, Dr. Salas Fernandez initiated the sorghum breeding program for biofuel production at Iowa State University. The main goal is to conduct research for the development of sorghum germplasm for biofuel production adapted to Iowa. The breeding program is centrally located in Ames, IA, with winter nursery activities in Puerto Rico and three testing locations in Iowa were experimental hybrids are evaluated every year.

Sorghum ethanol yields vary depending on the type of sorghum cultivated. Sweet sorghums can produce 900 gallons/acre, if we consider a standard composition, yields of 16 Tn of dry matter/ha and 90% conversion efficiency. Our yield trials demonstrate that biomass sorghum can produce up to 1,120 gallons/acre as a lignocellulosic feedstock, considering our highest yields of 35 Tn dry matter/ha, a standard composition and a 90% conversion efficiency. These biomass yields are at the level predicted for year 2038 in the 2016 DOE Billion Ton Report. Therefore, sorghum could become the preferred bioenergy crop, considering its high yield potential and the additional benefit of low input use, since it requires less nitrogen and water than corn.

In addition to the ethanol production from corn grain, commercial lignocellulosic biorefineries are processing corn-derived biomass, a dry and low volume feedstock. Recent evidence suggests that the greenhouse gas (GHG) benefit of cellulosic ethanol from corn stover is marginal relative to fossil fuel production. Therefore, sorghum biomass could be used as a new source of cellulosic fuel with net GHG savings relative to corn stover. The advantage will be to produce biofuel with a reduced environmental impact and without competing for food production. Considering that storage and transportation of high-tonnage biomass with high water content is a major limitations to the development of a strong bioeconomy, anaerobic digestion (on-farm or at centralized facilities) is considered a promising conversion technology to generate biogas. The ISU sorghum breeding program is developing novel germplasm for these goals and processing methods.

PI: Salas Fernandez, M.G.

Funding: Iowa Crop Improvement Association, Plant Sciences Institute, CALS, Department of Agronomy.

SOYBEAN

To meet the needs of farmers, industry, and consumers , we take a multi-pronged approach of breeding, phenotyping, genetics, and data sciences to increase yield and seed protein and to provide pest and disease resistance to soybean varieties primarily for food grade and non-GM markets. Both germplasm and cultivars developed under this project provide scientific advancement and economic benefit to stakeholders. The development of disease- and pest-tolerant varieties help reduce the application of chemicals to control pests and diseases.

Seed yield and protein improvement: Soybean production and profitability are impacted if crop doesn’t achieve its yield potential. We consider three main components to realize the true genetic potential in our varieties: (1) the assembly of favorable genetic combination of grain yield genes, and (2) the protection of yield from various deterrents, including pests and diseases, and (3) maximization of performance in a diverse set of growing and soil conditions.

Our breeding programs’ goals are: to improve agricultural production output and positively impact Iowa farmers and the agricultural industry through the development of new products (cultivars and germplasm), gene discovery, research insights on pertinent topics of importance to farmers, processors, and consumers; and developing selection strategies that lead to higher yield and new products that will improve market penetration. Several avenues being pursued for increased yield and profitability are:

• Selecting for yield related and predictive traits using state-of-the-art phenotyping technologies such as drones and ground robots.
• Improving genetic diversity and incorporating new “yield” genomic regions to current germplasm.
• Building prediction capabilities in breeding for production practices.
• Shifting the yield-protein correlation with strategic breeding approaches.
• Use digital phenotyping for above- and below-ground traits and gleans insights using advanced data analytics.

We mentor the next generation of plant breeders and develop and participate in teams that work towards improved productivity and profitability of producers and processors, and enhanced nutritional quality for animal and human health. We integrate breeding and research activities with student mentoring and learning experiences.

Yield protection: We work with plant pathologists to characterize our varieties for diseases and pests prior to commercialization. Due to environmental variation and its effect on disease and pest populations, we continually strive to create multiple levels of resistance against these important biotic factors in a high quality crop that meets domestic and international demands. We attempt to stack multiple defense traits against these pests and diseases by effective utilization and incorporation of resistance genes.

Increased profitability and Value-Added traits: Our group continues to work on value-added traits, such as modified fatty acid and carbohydrate profiles, and to explore alternative uses for soybean seed and other plant parts. We also have a major effort on increasing seed protein without compromising on seed yield.

PI: Singh, A.K.

Funding: Iowa Soybean Association, United Soybean Board, Iowa Crop Improvement Association, R F Baker Center for Plant Breeding, and North Central Soybean Research Program.