Drought Tolerant Wild Species Are the Important Sources of Genes and Molecular Mechanisms Studies: Implication for Developing Drought Tolerant Crops

Abstract

Despite recent agricultural advances, climate plays key role in today’s agricultural production. In fact, due to the recent climate change yield of many crops reduces marginally, especially due to the temperature increase, uncertainty of monsoon, and uneven distribution of precipitation. For all important crops, average yields are only a fraction somewhere between 20 and 50 % of record yields; these losses are mostly due to drought and high soil salinity, environmental conditions which will worsen in many regions because of global climate change. Therefore, the simplest way to increase agricultural productivity would be to improve the abiotic stress tolerance of crops. Wild species have adapted to a broad range of environments and developed rich genetic diversities for drought tolerances. Advanced backcross quantitative trait locus (QTL) analysis, the introgression libraries based on wild species as donors, and positional cloning of natural QTLs will play prevailing roles in elucidating the molecular control of drought tolerance. Considering the limitations of traditional plant breeding, the most promising strategy to achieve this goal will rely on the generation of transgenic plants expressing genes conferring tolerance. Drought tolerant genes and QTLs have been identified in Triticum dicoccoides and Hordeum spontaneum, and have great potential in wheat and barley improvement. Combining tolerant genes and QTLs in crop breeding programs aimed at improving tolerance to drought will be achieved within a multidisciplinary context. Wild genetic resistances to drought will be shifted in the future from field experiments to the farmer.