Project Number: 3625-21000-059-03
Start Date: Aug 01, 2014
End Date: Jul 31, 2015
Objective 1: The Kirksville breeding nursery will continue to maintain and select RS Amylomaize VII. Introgression of exotic maize germplasm from LAMP, GEM, Allelic Diversity Material and other plant introductions will be the source for trait improvement. Inbreeding following selection from high throughput grain and starch analyses will be made. These will include Am, total starch, RS, hydrolysis rate, DSC, and spectral studies for quality attributes. In addition, the development and modification of other analyses will be examined including grain density (100-kernal/volume), analysis of seed to determine special variability within the endosperm and starch granule using of digital image analysis. Continued development of in vitro fermentation bioassays will be investigated to better predict prebiotic efficacy. Improvements in our ability to collect molecular marker data will be prioritized to verify the presence of alleles using allele specific polymerase chain reaction (PCR) markers for future mapping studies. Also, evaluation of test crosses for yield, agronomic traits, and plant health will be taken in Ames, IA and Kirksville, MO. Parent line increases and crosses will be made in isolations and crossing blocks in Kirksville, MO. Objective 2: Breeding to generate and maintain potential SDS lines derived from GEM crosses will continue. In the Ames nursery 40 rows of partially inbred ae wx genotypes will be included. Continue collection of starch and grain phenotypic data will be accomplished from existing SDS inbreds to observe the extent of variation in grain and starch traits among materials believed to be homozygous ae wx. Molecular marker data will be used to verify genotypes using public marker data or self-designed allele-specific primer information. Improvements in generating marker data will be a priority. Technologies will be adopted to simplify, reduce or eliminate exposure to hazardous materials, yet provide undergraduates the skills to generate marker data in-house. Verification of other possible SDS genotypes will also be required where marker analysis can establish the presence and influence of the sbe1:gm67 allele. A comprehensive analysis of grain quality traits will be taken and selected lines grown in common environments to determine the extent of phenotypic variation. Analysis will include the determination of in vitro starch hydrolysis rates. Also, variations in Am values among ae wx genotypes will be studied to determine if variation in iodine affinities among ae wx materials can provide a rapid means of estimating starch branch chain lengths. Together with starch hydrolysis rates, Am values will be studied to determine if they can be used as a rapid method to estimate of digestibility rates. For Ae wx sbe1:gm67 starch, alterations in amylopectin structure can be determined following debranching of starches subjected to beta-amyolysis and verify possible hyperbranched amylopectin.