Strategies for increasing the yield potential of cereals: case of rice as an example

Abstract

Rice is the most important food crop. Worldwide, more than 3.5 billion people depend upon rice for more than 20% of their calories. Global rice demand is estimated to rise from 676 million tons in 2010 to 763 million tons in 2020 and to further increase to 852 million tons in 2035. This is an overall increase of 176 million tons in the next 25 years. To meet this challenge rice production on existing land must be increased. Grain production is largely influenced by the yield potential of rice varieties. Therefore, improvement in the yield potential of rice is the major strategy to increase world rice production. Various strategies to increase the yield potential include; (1) conventional hybridization and selection, (2) ideotype breeding, (3) hybrid breeding, (4) exploitation of wild species germplasm, (5) enhancement of photosynthesis, (6) genomic approaches and (7) physiological approaches. Rice has become a model plant for genetics and breeding research. Advances in molecular biology and genomics, proteomics and metabolics have opened new avenues to apply innovative approaches to rice breeding. Molecular‐assisted selection (MAS) has become an integral component of germplasm improvement. A large number of genes/QTLs for various traits have been tagged with molecular markers to apply MAS for trait improvement. Genome sequence data have become an important source for detecting allelic variation. It is now possible to precisely understand the role of epigenetic changes in gene expression, thus understanding the stability of various stresses under changing environments. All these advances when integrated with conventional breeding will result in designer rice varieties to meet the challenges of rice food security in 21th century.

OsmiR396d Affects Gibberellin and Brassinosteroid Signaling to Regulate Plant Architecture in Rice

“…An ideal plant architecture is a concept for high grain yield in rice (Oryza sativa) breeding (Khush, 2013). Moderate plant height and erect leaves are two of the main factors for ideal plant architecture in rice (Yuan, 2001).…”

Yield potential, potential yield and realized yield at farmer level of cereals with special reference to rice (<em>Oryza sativa</em> L.)

“…Ideotype breeding aimed at modifying the plant architecture is timetested strategy to increase the yield potential and selection for short-statured cereals such as rice, wheat and sorghum resulted in doubling their yield potential (Khush, 2013). The first short-statured rice variety, IR8, developed at the International Rice Research Institute (IRRI) had a combination of other desirable traits such as profuse tillering, dark green and erect leaves for good canopy architecture and sturdy stems for lodging resistance, which have also been included in the ideotype.…”

“…Many NPT lines with a comparatively higher yield potential have been developed through a crossing program between Tropical Japonica varieties and a semi-dwarf japonica breeding line to date and several of them out yielded the best improved varieties which had been developed earlier by as much as 1.0-1.5 t ha -1 . These breeding lines have also contributed to increased genetic diversity through introduction of japonica germplasm into indica breeding materials (Khush, 2013).…”

“…Global rice demand is estimated to rise from 676 million tons in 2010 to 852 million tons in 2035 with an overall increase of 26 % or 176 million tons in the next 25 years (Khush, 2013). Global wheat and maize demand is estimated to be 882 and 916 million tons, respectively, by 2027 (Cassman, 1999).…”

“…Grain production of rice is largely influenced by the yield potential of cultivated varieties so that improvement in the yield potential of rice varieties is the major strategy to increase world rice production (Khush, 2013). Studies on yield potential of crop plants can assist in identifying the production constraints in any cropping system (Constable and Bange, 2015).…”