Breeding for Drought Resistance in a Changing Climate
Drought is one of the major plagues affecting crop production worldwide. Climate changes will increase the frequency of droughts, particularly in Southeast Asia and Central America; by 2050 water shortages are expected to affect 67% of the world's population. Drought resistance has been always a challenge to plant breeders. Physiologists, biochemists, geneticists, and breeders have dissected drought resistance into individual components, with the aim of finding simple associated traits. Examples include proline accumulation, osmotic adjustment, stomatal conductance, canopy temperature, and various root characteristics. Today, most scientists agree that a drought resistance gene does not exist, and that differences in drought resistance are due to the effects of several genes, affecting different characters that interact with each other. This is because drought seldom occurs in isolation and often interacts with other stresses, mostly temperature extremes thus determining many combinations of stresses. Therefore, while drought is a global issue, its effects need to be addressed locally because every dry area has its own type of drought. Future research to increase the level of drought tolerance in crops needs to address the interaction between a number of traits and assemble those combinations of traits that maximize economic yields per unit of water used, possibly with the use of molecular tools.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
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