DEVELOPMENT OF CHEMICALLY MUTAGENIZED SOYBEAN POPULATIONS FOR IMPROVING SOYBEAN SEED OIL CONTENT AND FORWARD AND REVERSE GENETICS SCREENING

Author

Alaa A. Alaswad, Southern Illinois University CarbondaleFollow

Date of Award

5-1-2014

Degree Name

Master of Science

Department

Plant and Soil Science

First Advisor

Meksem, Khalid

Second Advisor

Lakhssassi, Naoufal

Abstract

Soybeans are among seeds the common plant foods that contains high protein contents and high oil. The protein provides about 35 to 38 percent of the seeds calories compared to around 20 to 30 percent in other legumes and many animal products. The quality of soy protein is notable and approaches the quality of meat and milk. Unlike many other good sources of protein, soybeans are low in saturated fat and are cholesterol-free. Its proteins provide all the important amino acids, most the amounts needed by humans (NSRL, 2010). As the most consumed vegetable oil in the world, soybean oil has been used substantially in the food industry (Soystats, 2010). Its utilization is determined by its fatty acid composition, with commodity soybean oil typically 13% palmatic acid (16:0), 4% stearic acid (18:0), 20% oleic acid (18:1), 55% linoleic acid (18:2), and 8% linolenic acid (18:3). The change of fatty acid profiles to improve soybean oil quality has been a long time goal of many researchers throughout the world. Biodiesel is an up and coming trend in energy production. Breeding effort can be undertaken in order to produce a higher energy profile soybean oil. Using ethyl-methanesulfonate (EMS) mutagenesis effects on DNA, significant changes to the genes and gene network underlying the protein and oil profile can be achieved. These changes are hard to accomplish using standard breeding techniques. In addition, high amount of linolenic and stearic acid are very important for fuel and biodiesel production, but are not good for food production due to the fact that such oil is oxidized easily and the food goes rancid quickly. However, soybean oil with elevated amount of oleic acid is desirable for food, because this monounsaturated fatty acid improves the nutrition and oxidative stability of soybean oil compared to other oils. In order to improve the quality of soybean oil and processed foods, chemically mutagenized soybeans have been developed in this project. Seeds harvested from individual M3 and M4 plants (from 2 successive years 2012 and 2013) were analyzed for protein content, oil composition, and content. Moreover, seven phenotypic traits including oil analysis (stearic, palmitic, oleic, linolenic and linoleic), seed protein content, weight of the seeds (High yield), seeds color, stem length, germination rates, and branch architecture were collected and analyzed in this project of soybean `Forrest' mutagenized population. The result of this research showed that there were 25 significantly different lines (p< 0.05) compare to the wild type, which is useful for developing mutants with altered oil and fatty acid compositions in soybean.