Limits...
Molecular Breeding Strategy and Challenges Towards Improvement of Blast Disease Resistance in Rice Crop.

Ashkani S, Rafii MY, Shabanimofrad M, Miah G, Sahebi M, Azizi P, Tanweer FA, Akhtar MS, Nasehi A - Front Plant Sci (2015)

Bottom Line: There is a need to develop strategies providing long-lasting disease resistance against a broad spectrum of pathogens, giving protection for a long time over a broad geographic area, promising for sustainable rice production in the future.So far, molecular breeding approaches involving DNA markers, such as QTL mapping, marker-aided selection, gene pyramiding, allele mining and genetic transformation have been used to develop new resistant rice cultivars.The paper briefly reviewed the progress of studies on this aspect to provide the interest information for rice disease resistance breeding.

View Article: PubMed Central - PubMed

Affiliation: Laboratory of Food Crops, Institute of Tropical Agriculture, Universiti Putra Malaysia Serdang, Malaysia ; Department of Agronomy and Plant Breeding, Yadegar -e- Imam Khomeini RAH Shahre-Rey Branch, Islamic Azad University Tehran, Iran.

ABSTRACT
Rice is a staple and most important security food crop consumed by almost half of the world's population. More rice production is needed due to the rapid population growth in the world. Rice blast caused by the fungus, Magnaporthe oryzae is one of the most destructive diseases of this crop in different part of the world. Breakdown of blast resistance is the major cause of yield instability in several rice growing areas. There is a need to develop strategies providing long-lasting disease resistance against a broad spectrum of pathogens, giving protection for a long time over a broad geographic area, promising for sustainable rice production in the future. So far, molecular breeding approaches involving DNA markers, such as QTL mapping, marker-aided selection, gene pyramiding, allele mining and genetic transformation have been used to develop new resistant rice cultivars. Such techniques now are used as a low-cost, high-throughput alternative to conventional methods allowing rapid introgression of disease resistance genes into susceptible varieties as well as the incorporation of multiple genes into individual lines for more durable blast resistance. The paper briefly reviewed the progress of studies on this aspect to provide the interest information for rice disease resistance breeding. This review includes examples of how advanced molecular method have been used in breeding programs for improving blast resistance. New information and knowledge gained from previous research on the recent strategy and challenges towards improvement of blast disease such as pyramiding disease resistance gene for creating new rice varieties with high resistance against multiple diseases will undoubtedly provide new insights into the rice disease control.

No MeSH data available.


Related in: MedlinePlus

Gene pyramiding scheme for cumulating six desired genes (G1–G6) which are present in 6 different parents or lines (P1–P6). The gene pyramiding consists of two steps, pedigree, which aims at cumulating of all target genes in a single genotype (Root genotype) by crossing and selection; the second step is fixation which aims at fixing the target genes into a homozygous state (Ideal/target genotype).
© Copyright Policy
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4644793&req=5

Figure 3: Gene pyramiding scheme for cumulating six desired genes (G1–G6) which are present in 6 different parents or lines (P1–P6). The gene pyramiding consists of two steps, pedigree, which aims at cumulating of all target genes in a single genotype (Root genotype) by crossing and selection; the second step is fixation which aims at fixing the target genes into a homozygous state (Ideal/target genotype).

Mentions: Pyramiding is the accumulation of genes into a single line or cultivar. In a gene pyramiding, strategy is to cumulate genes identified in multiple parents into a single genotype (Figure 3). The end product of a gene-pyramiding program is a genotype with all of the target genes. Pyramiding multiple resistance genes provides durable stress resistance expression in crops. Gene Pyramiding technique broadly is used for combining multiple disease or pest resistance genes for specific races of a pathogen or insect to develop durable resistance. It helps in crop improvement program and reduces breeding duration. Different R-genes often confer resistance to different isolates, races or biotypes. Combining their resistance broadens the number of races or isolates that a more than one character in a variety at the same time. Developing elite breeding lines and varieties often requires plant breeders to combine desirable traits from multiple parental lines, particularly in the case of disease resistance. Gene pyramiding can be accelerated by using molecular markers to identify and select plants that contain the desired allele combination in very early stage, resulting in obvious savings of resources including greenhouse or field space, water, and fertilizer. Therefore, marker technology can help existing plant breeding programs and allows researchers to access, transfer and combine genes at a rate and with a precision not previously possible. MAS based gene pyramiding could facilitate in pyramiding of genes effectively into a single genetic background (Joshi and Nayak, 2010). Factors such as the number of genes to be transferred, the distance between the target genes and flanking markers calculated in genetic mapping studies, the number of genotype selected in each breeding generation and the nature of germplasm is critical for successful gene pyramiding program. Gene pyramiding is considered one of the most effective strategies for achieving durable resistance against blast disease in rice (Shinoda et al., 1971; Hittalmani et al., 2000; Koide et al., 2010) and have successfully used for accumulating different blast resistance genes in elite rice cultivars (Table 3).


Molecular Breeding Strategy and Challenges Towards Improvement of Blast Disease Resistance in Rice Crop.

Ashkani S, Rafii MY, Shabanimofrad M, Miah G, Sahebi M, Azizi P, Tanweer FA, Akhtar MS, Nasehi A - Front Plant Sci (2015)

Gene pyramiding scheme for cumulating six desired genes (G1–G6) which are present in 6 different parents or lines (P1–P6). The gene pyramiding consists of two steps, pedigree, which aims at cumulating of all target genes in a single genotype (Root genotype) by crossing and selection; the second step is fixation which aims at fixing the target genes into a homozygous state (Ideal/target genotype).
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4644793&req=5

Figure 3: Gene pyramiding scheme for cumulating six desired genes (G1–G6) which are present in 6 different parents or lines (P1–P6). The gene pyramiding consists of two steps, pedigree, which aims at cumulating of all target genes in a single genotype (Root genotype) by crossing and selection; the second step is fixation which aims at fixing the target genes into a homozygous state (Ideal/target genotype).
Mentions: Pyramiding is the accumulation of genes into a single line or cultivar. In a gene pyramiding, strategy is to cumulate genes identified in multiple parents into a single genotype (Figure 3). The end product of a gene-pyramiding program is a genotype with all of the target genes. Pyramiding multiple resistance genes provides durable stress resistance expression in crops. Gene Pyramiding technique broadly is used for combining multiple disease or pest resistance genes for specific races of a pathogen or insect to develop durable resistance. It helps in crop improvement program and reduces breeding duration. Different R-genes often confer resistance to different isolates, races or biotypes. Combining their resistance broadens the number of races or isolates that a more than one character in a variety at the same time. Developing elite breeding lines and varieties often requires plant breeders to combine desirable traits from multiple parental lines, particularly in the case of disease resistance. Gene pyramiding can be accelerated by using molecular markers to identify and select plants that contain the desired allele combination in very early stage, resulting in obvious savings of resources including greenhouse or field space, water, and fertilizer. Therefore, marker technology can help existing plant breeding programs and allows researchers to access, transfer and combine genes at a rate and with a precision not previously possible. MAS based gene pyramiding could facilitate in pyramiding of genes effectively into a single genetic background (Joshi and Nayak, 2010). Factors such as the number of genes to be transferred, the distance between the target genes and flanking markers calculated in genetic mapping studies, the number of genotype selected in each breeding generation and the nature of germplasm is critical for successful gene pyramiding program. Gene pyramiding is considered one of the most effective strategies for achieving durable resistance against blast disease in rice (Shinoda et al., 1971; Hittalmani et al., 2000; Koide et al., 2010) and have successfully used for accumulating different blast resistance genes in elite rice cultivars (Table 3).

Bottom Line: There is a need to develop strategies providing long-lasting disease resistance against a broad spectrum of pathogens, giving protection for a long time over a broad geographic area, promising for sustainable rice production in the future.So far, molecular breeding approaches involving DNA markers, such as QTL mapping, marker-aided selection, gene pyramiding, allele mining and genetic transformation have been used to develop new resistant rice cultivars.The paper briefly reviewed the progress of studies on this aspect to provide the interest information for rice disease resistance breeding.

View Article: PubMed Central - PubMed

Affiliation: Laboratory of Food Crops, Institute of Tropical Agriculture, Universiti Putra Malaysia Serdang, Malaysia ; Department of Agronomy and Plant Breeding, Yadegar -e- Imam Khomeini RAH Shahre-Rey Branch, Islamic Azad University Tehran, Iran.

ABSTRACT
Rice is a staple and most important security food crop consumed by almost half of the world's population. More rice production is needed due to the rapid population growth in the world. Rice blast caused by the fungus, Magnaporthe oryzae is one of the most destructive diseases of this crop in different part of the world. Breakdown of blast resistance is the major cause of yield instability in several rice growing areas. There is a need to develop strategies providing long-lasting disease resistance against a broad spectrum of pathogens, giving protection for a long time over a broad geographic area, promising for sustainable rice production in the future. So far, molecular breeding approaches involving DNA markers, such as QTL mapping, marker-aided selection, gene pyramiding, allele mining and genetic transformation have been used to develop new resistant rice cultivars. Such techniques now are used as a low-cost, high-throughput alternative to conventional methods allowing rapid introgression of disease resistance genes into susceptible varieties as well as the incorporation of multiple genes into individual lines for more durable blast resistance. The paper briefly reviewed the progress of studies on this aspect to provide the interest information for rice disease resistance breeding. This review includes examples of how advanced molecular method have been used in breeding programs for improving blast resistance. New information and knowledge gained from previous research on the recent strategy and challenges towards improvement of blast disease such as pyramiding disease resistance gene for creating new rice varieties with high resistance against multiple diseases will undoubtedly provide new insights into the rice disease control.

No MeSH data available.


Related in: MedlinePlus