1 Oilseed Crops: Yield and Adaptations under Environmental Stress, First Edition. Edited by Parvaiz Ahmad. © 2017 John Wiley & Sons Ltd. Published 2017 by John Wiley & Sons Ltd. 1.1 Introduction Oilseed crops belong to numerous plant families and their seeds are used not only as a source of oil but also as raw materials for various oleo‐chemical industries. The raw materials act as a renew- able source of energy and are associated with power generation (Jankowski & Budzynski, 2003). Among various oilseed crops, the preferred ones are soybean, sesame, safflower, sunflower, groundnut, and castor (Weiss, 2000). The crops of sunflower, soybean, and canola offer good management options for irrigation reduction, thus enhancing the benefits of reduced input costs of these oilseed crops (Aiken & Lamm, 2006). There exists a positive correlation between soil water extraction and rooting depth in oilseed crops. The tap root, along with the well‐formed root growth system of safflower, allows this oilseed crop to extract moisture at greater depths from the soil. When safflower water requirements are satisfied with 68.6% and 78.4% water content, the crop provides the yield of 392 kgha −1 after only one turn of irrigation. Safflower yields 762 kgha −1 with two irrigations (Kar et al., 2007). Oilseed crops like soybean, sunflower, and canola are sus- ceptible to Sclerotinia sclerotiorum, a fungal pathogen that is responsible for a reduction in the yield of these crops. The application of sulfur as fertilizer on the oilseed crops results in increased concentration of oil as well as protein content of the Brassica seeds (Malhi et al., 2006). For the production of a ton of oilseed, approximately 12 Kg sulfur is required (Ghosh et al., 2000). Some 23.5% of protein content has been observed in canola after the application of 80 kgha −1 of nitrogen but this did not play a significant role in increasing the oil content (Ahmad et al., 2007). There has been an increased risk of blackleg in canola fields when crops are planted adjacent to canola stubble that is six months mature. To avoid serious damage by blackleg in canola fields, it is recom- mended that the crops should be sown in such a way that there is a distance of at least 500 m from last season’s canola stubble (Marcroft et al., 2004). Among the various oilseed crops, there are some anti‐nutritive compounds such as condensed tannins, inositol phosphates, and glucosino- lates, etc. All such anti‐nutritive compounds are responsible for lowering the nutritive value of oilseed crops. In most situations these compounds do not harm the crop plants (Matthaus & Angelini, 2005). Advances in plant technology and the advent of metabolic engineering have enabled the modification of oilseed crops, thus establishing transgenic crop plants. Such transgenic oilseed crops have novel biosynthetic genes taken from noncommercial plants that provide the oilseed plants with good fatty acids (Thelen & Ohlrogge, 2002). To modify the fatty acid content Oilseed crops: Present scenario and future prospects Sarah Waseem 1 , Sameen Ruqia Imadi 1 , Alvina Gul 1 , and Parvaiz Ahmad 2 1 Atta‐ur‐Rahman School of Applied Biosciences, National University of Sciences and Technology, Islamabad, Pakistan 2 Department of Botany, S.P. College, Jammu and Kashmir, India CHAPTER 1