Recipient Organization
FORT VALLEY STATE UNIVERSITY
1005 STATE UNIVERSITY DRIVE
FORT VALLEY,GA 31030
Performing Department
Plant Science 1810
Non Technical Summary
While demand for sorghum products is continuing to grow in the United States (U.S.), there is a huge potential for its export to several countries. The U.S. is the world's largest producer and exporter of grain sorghum, having produced 480 million bushels in 2016. Despite its multiple uses, genetic improvement is needed to increase its production as it is hampered by several pests and diseases. This project aims to explore and use genetic diversity to enhance the breeding program for biotic and abiotic stress resistance among all types of sorghum such as feed, silage, grain and sweet sorghum. We intend to adopt high-throughput genomics and phenomics tools to accelerate the conventional breeding. This project in-part aims to investigate the underlying genetic cause of plant resistance to insect pests through detailed studies on host-plant resistance mechanisms. Sorghum has innate resistance mechanisms to various insect pests which have been left unexploited. Therefore, this project particularly focusses on developing lines and feedstocks that are resistant to sugarcane aphids. Marker-assisted selection protocols will be used to introgress desirable genomic regions from well-known variety into an accepted open pollinated variety of sweet sorghum so that it is easily accessible to farmers. Furthermore, we will study the grain properties of sorghum for downstream processing and storage. Our last objective consists of studying the microbiome diversity surrounding the sorghum in relation to other plants to understand their role in plant resistance traits. Results of this project will be disseminated to the breeding community and sorghum producers through journal publications and presentations at national and international scientific meetings.
Animal Health Component
10%
Research Effort Categories
Basic
85%
Applied
10%
Developmental
5%
Goals / Objectives
The major goals of this project are to enhance sorghum genetic diversity for biotic and abiotic stress responses. The proposal mainly focuses on developing grain sorghum for sugarcane aphid resistance but not limited to other pests and drought resistance. The project also aims to improve some of the sweet sorghum lines using different breeding schemes while deploying marker-assisted technology to enhance breeding efficiency and selection. The specific objectives of the project areUnderstanding the genetic architecture underlying biotic and abiotic stress response mechanisms in sorghum by screening and identification of potential sorghum germplasm lines collected from Griffin repository for resistance to biotic and abiotic stressIntrogression of resistance gene region from TX2783 into commonly used open-pollinated varieties of sweet sorghum lines and development of marker-assisted selection protocols for screening potential sources germplasm in other crops of interestStudy the grain properties of sorghum with other millets for storage, handling and processing into other desirable food and feed products.Understanding the microbiome diversity for sorghum in relation to other dicots such as Lespedeza sps and Desmodium sps.
Project Methods
APPROACHPROJECT DESCRIPTIONMETHODSAll molecular biology related experiments will be done in lab 129, Stallworth bldg., Agriculture Research Station, FVSU.Objective 1: Understanding the genetic architecture underlying biotic and abiotic stress response mechanisms in sorghum by screening and identification of potential sorghum germplasm lines collected from Griffin repository for resistance to biotic and abiotic stressWe will obtain a subset of germplasm collection from Griffin germplasm unit; Plant Genetic Resources Conservation Unit, USDA, ARS, Griffin, GA after careful consideration and scrutiny of the study done by various sorghum researchers. One of our collaborators from USDA-ARS, Tifton, Dr. Xinzhi Ni, have screened two panels among grain and biofuel types of sorghum for sugarcane aphid resistance. We will also request Dr. Ni to share some of these lines for making association panel. We plan to make our association panel for grain and biofuel types with 300 individual lines in each panel. These 300 lines will be evaluated in 3 replications at FVSU new farm location. The evaluations for sugarcane aphid resistance will be done using 1-9 scale by Sharma et al. 2013 [26]. The panel will also be screened for other important agronomic characters such as trichome density, drought resistance and stay-green trait. DNA will be extracted using Qiagen Maxi Prep kit for 96 samples using Qiacube HT equipment in lab 129. These lines will be used to develop GBS markers by outsourcing at core sequencing facilities in University of Georgia. Most of these lines are readily available with GBS data on the public database and the same will be used for our study. Association mapping will be performed using TASSEL software by combining marker and phenotyping data[27]. The population structure derived from these results further reveal potential SNP markers associated with traits of our interest.We will use the potential lines of interest to study the expression pattern of genes under stress response. We will use two resistant and two susceptible accessions in three replications and uninfested plants will serve as controls or 0-time response. The lines will be grown in greenhouse and infested with sugarcane aphid equally on all lines. The affected tissue at different stages will be collected and stored for mRNA analysis. The mRNA will be isolated using Qiagen RNA isolation kit. The biological and technical replicates from these samples will be sent for sequencing to UGA core facility to identify the transcriptome profile of resistant and susceptible lines. The sequencing information will be used to annotate the various stress responsive genes. This information will further be tied to understand the host defense response system and the enzymes involved in plant-biotic interactions mechanisms.Trichome study will be done in coordination with and under the guidance of Dr. Nirmal Joshee and Dr. Xinzhi Ni. We will use the scanning electron microscope facility at the FVSU Agriculuture Research center to dissect the trichome character of resistant and susceptible plants.Objective 2: Introgression of resistance gene region from TX2783 into commonly used open pollinated varieties of sweet sorghum lines and development of marker-assisted selection protocols for screening potential sources germplasm in other crops of interest.There are several desired sweet sorghum lines for syrup production such as Top 76-6, Dale, and M81-E. These lines are susceptible to sugarcane aphid. We aim to introgress the resistance gene region from TX2783. TX2783 is a line known for its resistance to sugarcane aphid and the chromosome region containing resistance gene has been mapped. We will develop F1's by crossing Top 76-6 X TX2783. Further we will continue to make backcross with Tx2783 to enrich the regions around resistance gene using DNA markers. We would do this just by marker-assisted selection (crossing and then backcrossing multiple times and making sure we don't lose the region of interest from Tx2783). Thus, at the end we would have Dale (or other lines) with sugarcane aphid resistance. Following is the outline for backcross recurrent selection scheme for three different lines.Release of Commonly Used Sweet Cultivars with RKN and SCA ResistanceEntry Number Conversion List49=Top76-648=Dale115=M81E103=Honey Drip (RKN resistant)RKN Plant Material49x (103x49) F748x (103x48) F7115x (103 x 115) F7Aphid resistant material=Tx2783Cross the RKN plant material with Tx2783 and continue to BC to the recurrent parent but select those progeny that have Honey Drip DNA in the RKN resistance gene region and Tx2783 DNA in the SCA resistance gene regionContinue to BC until the F7 stageWe have ongoing collaborations with Dr. Karen Harris-Shultz, USDA-ARS Tifton and she has already developed the RKN plant material. TX2783 will be requested in our first objective along with other germplasms. We will also focus on development of genomic resources that can advance the relevant breeding program at FVSU. We will use these data to develop and advance mapping populations for genetic and genomic studies related to biotic and abiotic stress resistant varieties. Furthermore, this path leads to the development of marker-assisted selection protocols for screening potential sources of germplasm useful for forage breeding.These methods in the long run allow us to develop marker-assisted selection protocols that can be tested and used in other ongoing programs for MAS in forage crops such as Lespedeza and Desmodium. Dr. Thomas Terrill is currently working on Lespedeza and Desmodium and we will collaborate on developing these protocols in forage crops for small ruminants.Objective 3: Study and compare the grain properties of sorghum with other millets for storage, handling and processing into other desirable food and feed products.We aim to investigate potential factors affecting physical, thermal and flow properties of raw grain and flours, as well as examine the effect of moisture content on the resulting physical, thermal and flow properties of raw grain and flours. The best conditions will be determined for transportation and storage to maintain quality.The first objective will yield several sorghum grain lines resistant to sugarcane aphid. These lines further need a detailed evaluation on grain properties so that they can be marketed. The grain properties will add to our knowledge on storage and handling to control other stored pests. The grain properties will also supplement the data required for processing into flour and feed products. The flow properties will be studied in collaboration with Dr. Ajit Mahapatra, ARS, FVSU. We will also use other millets such as pearl millet and finger millet to arrive at decisions on nutrition and grain properties required to make desirable feeds for poultry and small ruminants.Objective 4. Understanding the microbiome diversity for sorghum in relation to other dicots such as Lespedeza sps and Desmodium sps.We will first begin with the understanding microbiome diversity around Lespedeza and Desmodium crop. Based on these studies we will study the microbiome interactions between sorghum and these dicot plants. These results will support for the nitrogen fixation and root nodule roles that support monocot plants. We will extend these studies to other monocots such as pearl millet.The plants will be grown in greenhouse and samples will be collected from root and leaf parts to process and extract the microbial population surrounding these parts. We will use Qiagen microbiome power soil extraction kits. The samples will be sent for sequencing to understand the metagenome diversity present in these samples. We will get the needed bioinformatics support from Dr. Wallace lab, UGA to extract useful and relevant data from these studies.