Contribution of Landraces in Wheat Breeding

Abstract

Agriculture is one of the oldest livelihood sources of mankind. Humans remained actively involved in the selection of favorable traits which resulted in significant changes in the phenotype and genotype of wild plants. In addition to man’s selection activities, environmental factors also played a significant contribution in the selection of various favorable traits suitable for man-made land and gardens. Combination of these activities resulted in the development of distinctive populations called “landraces” (Zeven 1998). Landraces are dynamic populations of cultivated plants having a historical background, genetically diverse and distinct identity, and good adaptation to local environment and that are associated with traditional farming systems (Villa et al. 2005). Dwivedi et al. (2016) stated that landraces are heterogeneous populations of domesticated species having great adaptation to local environment and can serve as a source of genetic variations that can be very helpful to combat the current and new challenges for farming in changing environments. Landraces are found phenotypically diverse and less productive compared to their cultivated types (Mir et al. 2020). However, regarding their quality attributes, landraces have been found highly nutritious compared to their cultivated ones (Azeez et al. 2018). Landraces played a major role in plant breeding by providing novel genes for various agronomic, quality, mineral, biotic, and abiotic traits (Azeez et al. 2018; Lopes et al. 2015). An impressive increase in yields per hectare was the result of the “Green Revolution” due the inclusion of high-yielding varieties (HYVs) having better response to inputs (Mir et al. 2020). After the inclusion of these high-yielding varieties, it was supposed that landraces will inevitably disappear with time (Frankel and Bennett 1970; Zeven 1998). However, these breeding activities led to genetic erosion and emergence of various modern cultivars that are prone to various biotic and abiotic stresses. It is estimated that approximately 75% loss of genetic diversity is observed in the last 100 years (Hammer et al. 1996). Globally, loss of genetic diversity is very alarming because it can be used to combat food scarcity problems in the long term. Therefore, it is very important to pay attention to collect, preserve, and grow these landraces as they guarantee the existence of variations that can be used for breeding of crops for the production of more quantity of food with high quality. Besides the inclusion of HYVs, landraces maintained their position by playing a key role in agricultural production, specifically in those environments where commercial cultivars failed their competitive advantage (Casañas et al. 2017).