Waterlogging Tolerance of Crops: Breeding, Mechanism of Tolerance, Molecular Approaches, and Future Prospects

Abstract

Submergence or flood is one of the major harmful abiotic stresses in the low-lying countries and crop losses due to waterlogging are considerably high. Plant breeding techniques, conventional or genetic engineering, might be an effective and economic way of developing crops to grow successfully in waterlogged condition. Marker assisted selection (MAS) is a new and more effective approach which can identify genomic regions of crops under stress, which could not be done previously. The discovery of comprehensive molecular linkage maps enables us to do the pyramiding of desirable traits to improve in submergence tolerance through MAS. However, because of genetic and environmental interaction, too many genes encoding a trait, and using undesirable populations the mapping of QTL was hampered to ensure proper growth and yield under waterlogged conditions Steady advances in the field of genomics and proteomics over the years will be helpful to increase the breeding programs which will help to accomplish a significant progress in the field crop variety development and also improvement in near future. Waterlogging response of soybean and major cereal crops, as rice, wheat, barley, and maize and discovery of QTL related with tolerance of waterlogging, development of resistant variety, and, in addition, future prospects have also been discussed.

QTL for chlorophyll fluorescence of barley plants grown at low oxygen concentration in hydroponics to simulate waterlogging

“…A possible explanation could be that these QTL affect other genes responsible for changes in the metabolic processes causing toxicity (Zeng et al 2013), ethylene production initiating aerenchyma formation or some of the other processes not directly related to energy production (Agarwal and Grover 2006;Colmer and Voesenek 2009;Ahmed et al 2013). However, the meta-analysis did confirm the presence of QTLs on 4H and 7H.…”

“…With the implementation of high-throughput SNP genotyping in barley, the bottleneck in genomic studies of abiotic stresses is now phenotyping (Xu and Crouch 2008;Close et al 2009;Ahmed et al 2013). WLT is related to many processes in the plant and for each of these processes; traits can be identified and used in phenotyping (Colmer and Voesenek 2009).…”

“…To date, many QTL have been identified for different abiotic stresses and crops, such as drought in wheat and rice (Ahmed et al 2013) and maize (Qiu et al 2007). With only seven chromosomes, barley has been widely used in different QTL analyses (Ahmed et al 2013;Close et al 2009) and also for WLT (Li et al 2013).…”

“…With only seven chromosomes, barley has been widely used in different QTL analyses (Ahmed et al 2013;Close et al 2009) and also for WLT (Li et al 2013). Li et al (2008) identified several QTL linked to leaf chlorosis, plant survival and plant residual biomass, while Zhou et al (2012) found four QTLs linked to an index calculated from scores of leaf chlorosis and plant survival of waterlogged plants in outdoor tanks filled with soil.…”

Phenotypic variation in root development of 162 soybean accessions under hypoxia condition at the seedling stage

“…Waterlogging after heavy and continuous rain often occurs in these areas (Ahmed et al, 2013), and soybeans are often grown in water-saturated soil in South-East Asia (Ghulamahdi et al, 2016). Nam Vang, a cultivar from Cambodia, showed waterlogging tolerance at the R2 reproductive stage, as indicated by a relatively stable yield (VanToai et al, 2010).…”