Performing Department
Plant Sciences
Non Technical Summary
In the United States, durum wheat is produced primarily in North Dakota and, therefore, is important to the state's economy. Consequently, most of the research on durum wheat and cultivar development in the United States occurs in North Dakota. Strong demand for high yielding cultivars that are resistant to diseases and possess excellent quality will persist in the domestic industry and export markets. Pasta manufacturers want strong gluten cultivars to ensure desired quality in the end products.The major yield and quality-limiting factors in durum wheat are pre-harvest sprouting and diseases, especially Fusarium head blight. There is a continuing decline in harvested durum acreage and production in North Dakota because of Fusarium head blight. The decline in harvested acreage and durum production in North Dakota is disastrous to the farm economy and has direct impact on the national pasta industry and the international export market. Fungicides could increase yield and other agronomic traits but the level of improvement is below the margin of the economic return. Although fungicides may reduce disease infections, using genetic resistance is the most environmentally safe and economical way to control diseases.Currently 90% of the durum acreage in North Dakota is planted with cultivars developed by NDSU. The newly developed durum wheat cultivars have higher yield and much better quality and some tolerance to FHB when compared to the older cultivars. The annual durum wheat production in North Dakota from 2012 to 2014 averaged 0.95 million tons having an average annual value of $430 million. The new cultivars Divide, Carpio, and Joppa also have better tolerance to FHB than the older cultivars. If breeding for increasing yield and/or disease resistance would increase production by 2%, it will add approximately 8.6 million dollars to the state economy annually.
Animal Health Component
0%
Research Effort Categories
Basic
15%
Applied
75%
Developmental
10%
Goals / Objectives
1. To develop durum wheat germplasm with high yield, high quality, and good agronomic characteristics.2. To identify new sources of resistance to biotic and abiotic stresses and determine their inheritance and use in the breeding program.
Project Methods
The major objective of the breeding program is to release durum cultivars that maximize the economic return to producers and provide high-quality durum wheat for the domestic pasta industry and international export markets. To achieve this objective, a pedigree breeding method is used to handle approximately 250 segregating populations each year. The pedigree breeding method used involves the evaluation and selection of parents and hybridization to provide useful gene recombinations. Approximately 75% of the crosses made are single crosses involving only elite adapted parents. The remainder of the crosses involve one parent that may be considered "exotic" but possesses desirable genes. In this case, 3-way crosses are utilized where the exotic parent's genetic contribution is one-third and the other two parents are elite adapted lines or cultivars. All crossing blocks and F1 generation materials are grown in the greenhouse. Single plants are selected for agronomic and quality traits, and disease resistance from space-planted F2 populations in the field in Casselton and Langdon, ND. The primary traits under selection are plant height, maturity, lodging, disease resistance, glume color, and kernel characteristics. Part of the F3 head rows are grown in the off-season winter nurseries in New Zealand and Yuma, AZ. These nurseries are planted in early November and heads are harvested in late February and April, to allow planting in North Dakota in April-May. Selected F3-derived F4 families are grown in head rows in breeding nurseries in North Dakota. The F5 generation is grown in ND and in a winter nursery, and seed is harvested for F6 yield trials in North Dakota. Approximately 4,500 rows (comprised of F3 and F5 generation material) are grown in a winter nursery each year. This saves two years in the length of time required to develop new, improved durum cultivars. The quality data is always compared to long-term check cultivars grown in the same environments. Preliminary yield trials are planted as two row plots using a lattice design with two replicates while advanced yield trials (AYT's) and elite durum advanced trials (EDA's) are planted in four plots using lattice designs with four replicates. The Uniform Regional Durum Nursery (URDN) is planted in a randomized complete block design with four replicates. All early generations are planted in one replicate and compared to relative resistant and susceptible checks. In addition to the modified pedigree breeding method we also are using the doubled haploid system in the breeding program.In addition to classical breeding methods and marker assisted selection in the breeding program we are in the process of incorporating novel breeding methodologies such as association mapping techniques, genotyping by sequencing, and genomic wide selection. These new methodologies provide a powerful approach for assessing the genetic diversity of the breeding germplasm, and generate information about the genetic diversity and population structure in elite breeding material which is necessary for crop improvement.The occurrence, widespread, and constant presence of FHB in the last 10 years has caught the attention of an increasing number of growers and scientists. This, in turn, has resulted in allocation of a considerable amount of time and resources to pathological research to further understand this disease and to release new durum germplasm with high yield and resistance to the disease. However, tan spot, Septoria, and rusts remain important durum diseases. The search for new sources of resistance and evaluation of lines with these diseases to identify resistant germplasm will remain a continuous process. In previous studies, we have identified lines that have a moderate level of Type II resistance to FHB. Some of these lines are from crosses of adapted durum wheat germplasm to Sumai 3 and Wangshuibai and others have a native moderate level of resistance. We have developed several populations (50 to 60) by crossing adapted durum cultivars/experimental lines to known sources of resistance such as the durum cultivars Divide, Carpio, Joppa, durum lines with Sumai 3 resistance, Tunisian lines, T. dicoccum, and T. carthlicum, and Langdon dicoccoides 3A and 7A substitution lines. We are evaluating these populations as F3:4 and subsequent generations for Type II disease resistance in fall and spring greenhouses and in the field FHB screening nursery at Prosper, ND. In the greenhouse, we are using the injection method for FHB evaluation (Stack and McMullen, 1985). As for the field, we have established a FHB field screening nursery at Carrington, Langdon, and Prosper, ND that can evaluate a maximum of 2,500, 2,500, and 8,000 lines, respectively. We also evaluate 1,000 durum accessions for FHB every year in Jiangsu, China.Tan spot is one of the major diseases that could cause serious economic losses to North Dakota producers and the durum industry. Singh et al., 2006 identified the tetraploid wheat TT283 as being resistant to tan spot Race 3. They also reported a single QTL peak in the interval between Xgwm285 and Xwmc366.2 that confers resistance to tan spot. We have developed several populations by crossing adapted cultivars/experimental lines to TT283 with the objective of developing cultivars resistant to tan spot. F5 and subsequent generations will be screened for tan spot in the greenhouse and genotyped using the two markers Xgwm285 and Xwmc366.2. In addition to tan spot, we routinely screen advanced lines for leaf rust (Puccinia tritici Eriks.) and stem rust (Puccinia graminis pers.:pers. F. sp. Tritici Eriks. & E. Henn) in collaboration with Dr. M. Acevedo and Dr. T. Friesen. Similarly in collaboration with Dr. M. Harris we will screen advanced lines for Hessian fly (Mayetiola destructor) and wheat midge.Because of the importance of low Cd to the international export market, we have crossed adapted durum cultivars/experimental lines to Hurani, Strongfield, and D041735 to develop durum cultivars with low Cd. We are using a modified pedigree breeding method that was described earlier to evaluate several segregating populations each year. F4:5 derived lines and subsequent generations are evaluated for Cd uptake in the field. In each generation we will cut 10 spikes using stainless steel knives from selected lines to be tested for Cd. Spikes are threshed in special modified head threshers to avoid any contact with metals other than stainless steel. Samples are sent to Dr. Mike Rutzke at the G36 Federal Nutrition Laboratory at Cornell University to be tested for Cd uptake. F5:6 lines that maintain low Cd uptake are advanced and evaluated for Cd uptake, agronomic, and quality traits in PYTs at two locations. Prior to phenotyping, all developed lines will be tested with the SNP molecular markers we identified earlier to increase selection efficiency and reduce cost. We have developed bi-parental populations to identify markers associated with low Cd in D041735 and allelism study to see if D041735 has the same gene(s) for low Cd as Haurani and Strongfield.