Limits...
Understanding rice adaptation to varying agro-ecosystems: trait interactions and quantitative trait loci.

Dixit S, Grondin A, Lee CR, Henry A, Olds TM, Kumar A - BMC Genet. (2015)

Bottom Line: Rice requires better adaptation across a wide range of environments and cultivation practices to adjust to climate change.This study provides a wider picture of the genetics and physiology of adaptation of rice to wide range of environments.With a complete understanding of the processes and relationships between traits and trait groups, marker-assisted breeding can be used more efficiently to develop plant types that can combine all or most of the beneficial traits and show high stability across environments, ecosystems, and cultivation practices.

View Article: PubMed Central - PubMed

Affiliation: International Rice Research Institute, DAPO Box 7777, Metro Manila, Philippines. s.dixit@irri.org.

ABSTRACT

Background: Interaction and genetic control for traits influencing the adaptation of the rice crop to varying environments was studied in a mapping population derived from parents (Moroberekan and Swarna) contrasting for drought tolerance, yield potential, lodging resistance, and adaptation to dry direct seeding. A BC2F3-derived mapping population for traits related to these four trait groups was phenotyped to understand the interactions among traits and to map and align QTLs using composite interval mapping (CIM). The study also aimed to identify QTLs for the four trait groups as composite traits using multivariate least square interval mapping (MLSIM) to further understand the genetic control of these traits.

Results: Significant correlations between drought- and yield-related traits at seedling and reproductive stages respectively with traits for adaptation to dry direct-seeded conditions were observed. CIM and MLSIM methods were applied to identify QTLs for univariate and composite traits. QTL clusters showing alignment of QTLs for several traits within and across trait groups were detected at chromosomes 3, 4, and 7 through CIM. The largest number of QTLs related to traits belonging to all four trait groups were identified on chromosome 3 close to the qDTY 3.2 locus. These included QTLs for traits such as bleeding rate, shoot biomass, stem strength, and spikelet fertility. Multivariate QTLs were identified at loci supported by univariate QTLs such as on chromosomes 3 and 4 as well as at distinctly different loci on chromosome 8 which were undetected through CIM.

Conclusion: Rice requires better adaptation across a wide range of environments and cultivation practices to adjust to climate change. Understanding the genetics and trade-offs related to each of these environments and cultivation practices thus becomes highly important to develop varieties with stability of yield across them. This study provides a wider picture of the genetics and physiology of adaptation of rice to wide range of environments. With a complete understanding of the processes and relationships between traits and trait groups, marker-assisted breeding can be used more efficiently to develop plant types that can combine all or most of the beneficial traits and show high stability across environments, ecosystems, and cultivation practices.

No MeSH data available.


Related in: MedlinePlus

Morphological differences between rice cultivars Swarna (S) and Moroberekan (M). a Plant type, tiller and panicle number; b Stem diameter (first to fourth internode from the bottom); c Root architecture at seedling stage; d Flag leaf length and width. e Panicle architecture and grains per panicle; f Grain type and size
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
getmorefigures.php?uid=PMC4526302&req=5

Fig1: Morphological differences between rice cultivars Swarna (S) and Moroberekan (M). a Plant type, tiller and panicle number; b Stem diameter (first to fourth internode from the bottom); c Root architecture at seedling stage; d Flag leaf length and width. e Panicle architecture and grains per panicle; f Grain type and size

Mentions: The cultivars Moroberekan and Swarna showed high contrast for plant type and other key traits that determine performance in terms of the four trait groups considered in this study (Fig. 1). Additional file 1 presents the differences between Moroberekan and Swarna for some of the key traits that determine the morphology and yield of rice under varying environmental conditions. Swarna, being the high-yielding parent, showed higher values for yield and for traits related to yield potential such as tiller and panicle number in all three environmental conditions (well-watered, drought, and direct-seeded). However, the higher tolerance of Moroberekan to drought allowed it to maintain higher spikelet fertility compared to Swarna under severe drought stress. The yield decline under drought stress (compared to the non-stress treatment) in Swarna was much higher as compared to Moroberekan, showing the higher susceptibility of Swarna to drought. Swarna showed quicker emergence and a higher number of nodal roots while Moroberekan showed a higher percentage of deep roots under lowland drought at maturity. However, Swarna showed higher root mass density at shallow depths and Moroberekan showed higher stem diameter and sturdiness.Fig. 1


Understanding rice adaptation to varying agro-ecosystems: trait interactions and quantitative trait loci.

Dixit S, Grondin A, Lee CR, Henry A, Olds TM, Kumar A - BMC Genet. (2015)

Morphological differences between rice cultivars Swarna (S) and Moroberekan (M). a Plant type, tiller and panicle number; b Stem diameter (first to fourth internode from the bottom); c Root architecture at seedling stage; d Flag leaf length and width. e Panicle architecture and grains per panicle; f Grain type and size
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4526302&req=5

Fig1: Morphological differences between rice cultivars Swarna (S) and Moroberekan (M). a Plant type, tiller and panicle number; b Stem diameter (first to fourth internode from the bottom); c Root architecture at seedling stage; d Flag leaf length and width. e Panicle architecture and grains per panicle; f Grain type and size
Mentions: The cultivars Moroberekan and Swarna showed high contrast for plant type and other key traits that determine performance in terms of the four trait groups considered in this study (Fig. 1). Additional file 1 presents the differences between Moroberekan and Swarna for some of the key traits that determine the morphology and yield of rice under varying environmental conditions. Swarna, being the high-yielding parent, showed higher values for yield and for traits related to yield potential such as tiller and panicle number in all three environmental conditions (well-watered, drought, and direct-seeded). However, the higher tolerance of Moroberekan to drought allowed it to maintain higher spikelet fertility compared to Swarna under severe drought stress. The yield decline under drought stress (compared to the non-stress treatment) in Swarna was much higher as compared to Moroberekan, showing the higher susceptibility of Swarna to drought. Swarna showed quicker emergence and a higher number of nodal roots while Moroberekan showed a higher percentage of deep roots under lowland drought at maturity. However, Swarna showed higher root mass density at shallow depths and Moroberekan showed higher stem diameter and sturdiness.Fig. 1

Bottom Line: Rice requires better adaptation across a wide range of environments and cultivation practices to adjust to climate change.This study provides a wider picture of the genetics and physiology of adaptation of rice to wide range of environments.With a complete understanding of the processes and relationships between traits and trait groups, marker-assisted breeding can be used more efficiently to develop plant types that can combine all or most of the beneficial traits and show high stability across environments, ecosystems, and cultivation practices.

View Article: PubMed Central - PubMed

Affiliation: International Rice Research Institute, DAPO Box 7777, Metro Manila, Philippines. s.dixit@irri.org.

ABSTRACT

Background: Interaction and genetic control for traits influencing the adaptation of the rice crop to varying environments was studied in a mapping population derived from parents (Moroberekan and Swarna) contrasting for drought tolerance, yield potential, lodging resistance, and adaptation to dry direct seeding. A BC2F3-derived mapping population for traits related to these four trait groups was phenotyped to understand the interactions among traits and to map and align QTLs using composite interval mapping (CIM). The study also aimed to identify QTLs for the four trait groups as composite traits using multivariate least square interval mapping (MLSIM) to further understand the genetic control of these traits.

Results: Significant correlations between drought- and yield-related traits at seedling and reproductive stages respectively with traits for adaptation to dry direct-seeded conditions were observed. CIM and MLSIM methods were applied to identify QTLs for univariate and composite traits. QTL clusters showing alignment of QTLs for several traits within and across trait groups were detected at chromosomes 3, 4, and 7 through CIM. The largest number of QTLs related to traits belonging to all four trait groups were identified on chromosome 3 close to the qDTY 3.2 locus. These included QTLs for traits such as bleeding rate, shoot biomass, stem strength, and spikelet fertility. Multivariate QTLs were identified at loci supported by univariate QTLs such as on chromosomes 3 and 4 as well as at distinctly different loci on chromosome 8 which were undetected through CIM.

Conclusion: Rice requires better adaptation across a wide range of environments and cultivation practices to adjust to climate change. Understanding the genetics and trade-offs related to each of these environments and cultivation practices thus becomes highly important to develop varieties with stability of yield across them. This study provides a wider picture of the genetics and physiology of adaptation of rice to wide range of environments. With a complete understanding of the processes and relationships between traits and trait groups, marker-assisted breeding can be used more efficiently to develop plant types that can combine all or most of the beneficial traits and show high stability across environments, ecosystems, and cultivation practices.

No MeSH data available.


Related in: MedlinePlus