Location: Corn Insects and Crop Genetics Research2011 Annual Report
1a. Objectives (from AD-416)
The objectives of this research are to 1) breed high yielding corn with enhanced nutritional value for the Northern Corn Belt, 2) adapt the corn to the conditions found on farms using sustainable farming practices, and 3) achieve acceptance of these cultivars by end users such as livestock farmers and poultry producers.
1b. Approach (from AD-416)
1)Interact with a team including USDA and ISU scientists and PFI to select varieties for breeding, plan experiments, test corn, develop methods for screening lines for desired traits, and for outreach and publication efforts. 2)Utilize a crossing, inbreeding and test-cross facilitated breeding program to identify and fix corn lines with desired traits, and crossing and recurrent selection to improve desired traits such as the content of methionine and lysine in grain. 3)In conjunction with others, fully utilize and improve the accuracy of a near infra red spectroscopy-based test for screening whole grain samples for essential amino acids. 4)Evaluate the adaptation of lines and their hybrids to organic farming systems in the Northern Corn Belt, including their agronomic traits and their ability to suppress weeds. 5)Help coordinate on-farm trials with hybrids and publicize the results. 6)Interact with end-users such as seed and organic poultry companies with advice and to help facilitate poultry company sponsored feeding trials with grain from our cultivars.
3. Progress Report
We identified soft endosperm cultivars and breeding lines that have a higher percentage of lysine and methionine in their protein and have greater stability in producing methionine than hard endosperm cultivars. In particular we found unique lines that produce high methionine content but do not reduce seed weight. We continued breeding for high methionine inbreds with this characteristic and made a new set of crosses with agronomically adapted cultivars. We screened plants homozygous for the trait and sent them to a winter nursery in Puerto Rico for crossing with high methionine testers. Spring 2011, the resulting hybrids were planted at East Troy, WI and on three sites in Iowa with ARS cooperators. Other segregating lines were planted in nurseries in 2011 for further selection and fixation of the high methionine trait. The ‘culture shock’ phenomenon, associated with introducing conventional seed onto organic soils was documented as 16% less chlorophyll content in tops for a set of inbreds that had previously been grown or selected under conventional conditions rather than organic conditions. Whether such affects are due to genetic, epigenetic, or endophytic relationships is still unclear. One of the most exciting findings of the project is that through targeted breeding, it is possible to increase the yields of protein and essential amino acid on a per acre basis by using breeding and associative bacteria. Protein content and grain yield are usually thought of as having a negative relationship and protein contents of conventional hybrids have plunged as grain yields have increased. To increase yield of protein, we are screening for protein and essential amino acid yields under low nitrogen conditions and response to endophytic bacteria. On the basis of positive results from 2008 and 2009, we investigated differences between varieties, different microorganisms, effects of seed disinfection, and foliar sprays. We also tested whether these organisms coupled with seed disinfection can help eliminate Fusarium fungal species which commonly inhabit corn plants and seed and antagonize internal colonization by bacteria. Corn is being tested and selected for N fixation using the 15N natural abundance technique, but we are moving to supplement that approach with other methods. In particular we found: 1) A few cultivars and hybrids strongly respond to bacterial inoculation with increases in grain yield, protein, and essential amino acids. Some of these hybrids out-yielded conventional hybrids for grain yield when they were inoculated with bacteria and they also yielded considerably more protein (22-40%) and essential amino acids on a per acre basis; and, 2) Disinfection of seed decreased yield in conventional hybrids but not in the new hybrids; this seemed mainly due to reduced plant population density. The Authorized Departmental Officer's Designated Representative monitors activities for the project by frequent mutual visits, phone calls, and emails for joint planning of experiments, sharing nursery rows and yield tests, sharing results and germplasm, and reporting results.