Genetic and molecular technologies for achieving high productivity and improved quality in sunflower

Abstract

Globally, sunfower (Helianthus annuus L.) occupies a prominent posi tion among edible oilseed crops, and its credit goes to the systematic breeding efforts performed in this crop, especially for oil content during the frst half and exploitation of heterosis in the middle of the second half of the twentieth century. Today, sunfower ranks second biggest crop after maize cultivated through hybrid seed worldwide. Primarily, major breeding objectives in sunfower focused in seed and oil yield. However, with changing market demands, current breeding objectives in sunfower have shifted to oil quality along with productivity constraints prevalent in specifc agro-climatic zone. The narrow genetic base of cultivated sunfower led main thrust for extensive utilization of both wild genetic resources and mutagenesis through conventional breeding for a long time now. This resulted in the creation of substantial genetic variability for different traits of interest, but progress in this feld has been relatively slow and limited. The rapid advances in marker technology paved the way for molecular breeding in sunfower as a tool for acceleration of the breeding process. From the last three decades, a large number of random as well as gene-specifc molecular markers have been developed and validated in sunfower, but their application depends on the research objectives. Moreover, recent large scale DNA sequencing and high-throughput screening techniques transformed the way that crop breeding is performed. In present day, reverse genetics approaches have also become an important goal for researcher in many crops including sun fower. New molecular methodologies such as TILLING including EcoTILLING which entails detection of natural variation allowed to utilize induced as well as existing genetic variation for development of new varieties. In this chapter, we sum marized information on available genetic resources, genetics of different traits together with validated molecular markers for their utilization in sunfower breeding programme. Finally, this chapter also reviewed the application of product-based alternative new breeding techniques, as the products developed in this manner could occur naturally over time.