USA soybean germplasm has a narrow genetic base that could be augmented by alleles from the wild species Glycine soja which positively influence agronomic traits. The objective of this study was to identify such alleles for yield and yield component QTL (quantitative trait loci). Two populations of 150 BC2F4 lines were generated from a mating between recurrent parent Glycine max 7499 and donor parent Glycine soja PI 245331 with one line in each population tracing back to the same BC2 plant. Population A was used for the QTL identification analysis and population B was used for the QTL verification test. The population A lines were genotyped at 120 SSR marker loci and one phenotype marker, covering a total map length of 1506 cM in 20 linkage groups with an average interval size of 12.5 cM. There were nine putative QTL significantly (Pandlt;0.0001, LODandgt;3.0) associated with yield and yield component traits across 3 environments. One QTL for seed yield was identified using the combined data; the G. soja allele at satt511 on LG-A1 was associated with increased seed yield (LOD=4.3) with an additive yield effect of 190 235 kg ha-1 depending on the QTL analysis method. The phenotypic variance accounted for by the QTL at satt511 was 12%. This QTL also provided a significant yield increase across environments in the validation population; lines that were homozygous for the G. soja allele at satt511 demonstrated a 6.3% (P=0.037) yield increase over lines that were homozygous for the G. max allele. One seed filling period QTL was identified at satt335 (LOD=4.0) on LG-F with an additive effect of +1 day. This QTL also provided a +1 day additive effect (LOD=3.3) on maturity. These results demonstrate the potential of using exotic germplasm to improve soybean yield.

Many soybean [Glycine max (L.) Merrill] cultivars have narrow leaflet shape but it is not known if all of these lines derive this trait from the ln gene or another locus. This project was conducted to determine the inheritance of the narrow leaflet trait in several soybean genotypes and wild [Glycine soja Sieb. et Zucc.] accessions, and also to determine the allelism of the genes for this trait in the selected lines. The parents, F1, F2 and F2:3 generations were grown at Kentland Research Farm near Blacksburg, VA or in the greenhouse. The F2 and F2:3 generations (where available) were observed for segregation in leaflet shape. The populations were scored as having either broad or narrow leaflets using visual classification and leaf measurements when necessary. 'Camp' was crossed with broad leaflet parent 'Essex' to study the inheritance of the narrow leaflet trait in Camp. Observation of the F2 and F2:3 generations lead to the conclusion that a single recessive gene controls leaflet shape in Camp. Narrow leaf parents 'SRF 400' and Camp were crossed with lines having the ln gene (T41, S56, and D64-4731). None of the crosses among Camp, T41, SRF 400, S56 and D64-4731 segregated for leaflet shape in the F2 generation leading to the conclusion that they all have the ln allele at the same locus controlling lanceolate leaflet shape. T313, a line containing a gene for narrow rugose leaflets (lnr), was crossed with Camp to study allelism between the lnr and ln genes. Segregation for leaflet shape was observed in the F2 and F2:3 generations allowing the conclusion that the lnr gene controlling the narrow rugose leaflet trait in T313 is at a locus independent from the ln gene. A deficiency of narrow rugose plants was observed in all of the populations with T313 as a parent, and was theorized as being caused by selection against lnr gametes. After adjustment for the lnr deficiency, the F2 data appeared to fit a 9 broad : 3 narrow : 4 narrow rugose ratio. Three G. soja lines were crossed to broad and narrow leaflet parents and the F2 generations were examined to determine the inheritance of the very narrow leaf phenotype. The results indicate that there are one or two recessive genes controlling narrow leaflet shape in the G. soja accessions, which are not allelic to the ln gene. Since these populations were not advanced to the F3 generation, definite conclusions cannot be drawn about the genetics of the very narrow leaf phenotype. / Master of Science

As the global population rises, the demand for food increases which underscores a need for improvement in food security. Disease pressures are a major concern surrounding sustainable agriculture. Static crop populations, containing little to no genetic diversity, are vulnerable to diverse pathogen populations. Wild relatives of crop plants are a reservoir for new disease resistance traits that can be introgressed into cultivated crops. The identification of novel disease resistance is of paramount importance because pathogen co-evolution is not only defeating current resistance genes (R genes) but chemical controls as well. Phytophthora sojae (P. sojae), the causal agent of Phytophthora root and stem rot disease, reduces soybean harvests worldwide. We developed an approach to screen for new R genes that recognize core effectors from P. sojae. We expect R genes identified by these screens to be durable because P. sojae requires core effectors for virulence. We utilized effector-based screening to probe Glycine soja germplasm with core RXLR effectors from P. sojae to search for novel R genes. We developed segregating populations from crosses of P. sojae resistant G. soja germplasm with susceptible G. max cultivar Williams to determine inheritance of potential R genes in germplasm that responded to core effectors. We are using marker assisted breeding to map disease resistance traits in recombinant inbred (RI) lines. To better understand pathosystems, we examined host resistance and susceptibility using bioinformatics. We analyzed the interaction between Arabidopsis thaliana ecotype Col-0 and Hyaloperonospora arabidopsidis isolate Emwa1 using a publicly available RNA time-course experiment. We describe a new algorithm to sort genes into time-point specific clusters using activation and repression parameters. Gene ontology annotations were used to identify defense genes with unique expression profiles, and A. thaliana null mutants for these genes were significantly more susceptible to Emwa1 than wild-type. We plan to use these tools to rapidly identify and guide introgression of durable disease resistance into crop species. / Ph. D.

The diploma thesis deals with the development of the market for protein crops. The literature research deals one hand with the distribution and morphology of legumes, and on second hand with the structure and chemical composition of seeds of selected species (pea, soybean and lupine). The literature research also covers the production of protein concentrates and their commercialization. The practical part is mainly engaged in the analysis of market developments of selected species of legumes in the Czech Republic, especially during the years 2000 - 2015, in comparison with the market development of the individual European states (Germany, Austria, Poland, Slovakia and France). The outcome of this diploma thesis is the ordination of statistical data available in clear graphical and tabular outputs, it does not miss time series evaluation of development of individual crops in both the Czech Republic and other selected countries.