Location: Crop Genetics Research2012 Annual Report
1a. Objectives (from AD-416):
Our objective is to identify and utilize exotic germplasm to improve U.S. soybean productivity. We will deliver 1) high yielding lines derived from exotic germplasm that are available to all U.S. soybean breeders developing new cultivars, 2) quantitative trait loci(QTL) affecting yield with the positive allele derived from exotic germplasm and the DNA markers associated with these loci, and 3) lines derived from exotic germplasm that will improve the yield and seed quality in the Early Planting Production System of the midsouth. To improve yield and seed quality of soybean varieties grown in the early soybean production system by deriving improved lines from exotic germplasm.
1b. Approach (from AD-416):
High-yielding experimental lines will be developed from exotic germplasm to expand the genetic base and accelerate the rate of yield improvement of soybean production in the U.S. This breeding project will use over 150 soybean introductions and many experimental lines derived from these introductions in past USB projects. These introductions include modern Asian varieties that are unrelated to U.S. cultivars, diverse primitive varieties that predate scientific plant breeding, and wild soybean. The number of exotic lines that we are using exceeds the total number of all the ancestral lines, regardless of the size of their contribution, of all of the current varieties grown in the U.S. Our projects are located in all major soybean-growing regions of the U.S. so that new genes for increasing yield from exotic germplasm will be accessible to soybean breeders and eventually soybean farmers in every soybean-producing state. We will also be testing exotic germplasm and lines derived from exotic germplasm in the Early Planting Production System of the mid-south to select for high yield and improved germination rates in the harvested seeds. Concurrently with developing high yielding experimental lines, we are developing sets of lines (mapping populations) that will allow us to begin the process of identifying specific genes (quantitative trait loci, QTL) from exotic germplasm that can increase yield of commercial varieties and then to confirm those QTL in independent populations.
3. Progress Report:
LG01-5087-5, a high-yielding breeding line derived from exotic soybeans, was officially released by ARS on March 8, 2012. This was the first public soybean release derived from PI 438151. Six breeding lines with high-germinability were tested for multiple seed traits at three harvest dates in Stoneville, MS, and two harvest dates at North Carolina (NC). Five parental lines and six cultivars were also tested. Among the lines tested, breeding line DS25-1 had higher percentages of germination than cultivar AG 4903 for all three harvest dates at Stoneville, MS, and both harvest dates at NC. DS25-1 was the only line tested that had a germination percentage as high as 90 after 28 days in the field at Stoneville, MS. AG4903 had larger seed that was more wrinkled and had more green discoloration and more purple seed stain than DS25-1. Although both lines exceeded the minimal level of acceptable seed damage at NC without monetary loss (2%), AG 4903 averaged projected losses of $380 per 1,000 bushels of grain compared to only $140 for DS25-1. Breeding line DS34-1 had higher germination and vigor and lower percentages of hard seed, seed wrinkling, green seed, and seed fungus than cultivar LD00-3309. Monetary losses due to seed damage were present for LD00-3309 after harvest delays of 14 and 28 days at Stoneville, MS, but were never present for DS34-1 after any harvest. Activities for this project were monitored by the ADODR through visits, reports, and meetings.