Drought Resistance Improvement in Rice: An Integrated Genetic and Resource Management Strategy

Abstract

Drought is the major constraint to rice production in rainfed areas across Asia and subSaharan Africa. In the context of current and predicted water scarcity, increasing irrigation is generally not a viable option for alleviating drought problems in rainfed rice-growing systems. It is therefore critical that genetic management strategies for drought focus on maximum extraction of available soil moisture and its effi cient use in crop establishment and growth to maximize biomass and yield. Extensive genetic variation for drought resistance exists in rice germplasm. However, the current challenge is to decipher the complexities of drought resistance in rice and exploit all available genetic resources to produce rice varieties combining drought adaptation with high yield potential, quality, and resistance to biotic stresses. The strategy described here aims at developing a pipeline for elite breeding lines and hybrids that can be integrated with efficient management practices and delivered to rice farmers. This involves the development of high-throughput, highprecision phenotyping systems to allow genes for yield components under stress to be effi ciently mapped and their effects assessed on a range of drought-related traits, and then moving the most promising genes into widely grown rice mega-varieties, while scaling up gene detection and delivery for use in marker-aided breeding.

Genotypic Variation in Nitrogen Uptake during Early Growth among Rice Cultivars under Different Soil Moisture Regimes

“…In addition to agronomical methods, the genetic improvement of adaptability to water-deficient conditions is one of the greatest challenges for sustainable rice production (Kamoshita, 2011;Serraj et al, 2011). For recent advances in molecular technology to be applied to practical breeding program, it is necessary to narrow the large gap between the knowledge of gene level and the plant performance in the field.…”

Genotypic Variation in Biomass Production at the Early Vegetative Stage among Rice Cultivars Subjected to Deficient Soil Moisture Regimes and Its Association with Water Uptake Capacity

“…The degree of yield and biomass reduction caused by water stress is influenced by environmental factors such as the strength and duration of drought, and genotypic differences in drought resistance (Kamoshita, 2011;Serraj et al, 2011).…”

Rice genotypes for drought tolerance: morphological and transcriptional evaluation of auxin-related genes

“…However, to obtain high yields, conventional breeding programs have had limitations in generating new drought tolerant cultivars (Ramya et al 2010;Serraj et al 2011).…”