Epistasis for Three Grain Yield Components in Rice (Oryxa sativa L.)

The genetic basis for three grain yield components of rice, 1000 kernel weight (KW), grain number per panicle (GN), and grain weight per panicle (GWP), was investigated using restriction fragment length polymorphism markers and F4 progeny testing from a cross between rice subspecies japonica (cultivar Lemont from USA) and indica (cv. Teqing from China). Following identification of 19 QTL affecting these traits, we investigated the role of epistasis in genetic control of these phenotypes. Among 63 markers distributed throughout the genome that appeared to be involved in 79 highly significant (P < 0.001) interactions, most (46 or 73%) did not appear to have “main” effects on the relevant traits, but influenced the trait(s) predominantly through interactions. These results indicate that epistasis is an important genetic basis for complex traits such as yield components, especially traits of low heritability such as GN and GWP. The identification of epistatic loci is an important step toward resolution of discrepancies between quantitative trait loci mapping and classical genetic dogma, contributes to better understanding of the persistence of quantitative genetic variation in populations, and impels reconsideration of optimal mapping methodology and marker-assisted breeding strategies for improvement of complex traits.

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Overdominant Epistatic Loci Are the Primary Genetic Basis of Inbreeding Depression and Heterosis in Rice. II. Grain Yield Components

Genetics ◽

10.1093/genetics/158.4.1755 ◽

2001 ◽

Vol 158 (4) ◽

pp. 1755-1771 ◽

Cited By ~ 2

Author(s):

L J Luo ◽

Z-K Li ◽

H W Mei ◽

Q Y Shu ◽

R Tabien ◽

...

Keyword(s):

Grain Yield ◽

Inbreeding Depression ◽

Yield Components ◽

Genetic Basis ◽

Mixed Model ◽

Gene Action ◽

Recombinant Inbred Lines ◽

Hybrid Breakdown ◽

Multilocus Genotypes ◽

Grain Yield Components

Abstract The genetic basis underlying inbreeding depression and heterosis for three grain yield components of rice was investigated in five interrelated mapping populations using a complete RFLP linkage map, replicated phenotyping, and the mixed model approach. The populations included 254 F10 recombinant inbred lines (RILs) derived from a cross between Lemont (japonica) and Teqing (indica), two backcross (BC) and two testcross populations derived from crosses between the RILs and the parents plus two testers (Zhong413 and IR64). For the yield components, the RILs showed significant inbreeding depression and hybrid breakdown, and the BC and testcross populations showed high levels of heterosis. The average performance of the BC or testcross hybrids was largely determined by heterosis. The inbreeding depression values of individual RILs were negatively associated with the heterosis measurements of the BC or testcross hybrids. We identified many epistatic QTL pairs and a few main-effect QTL responsible for >65% of the phenotypic variation of the yield components in each of the populations. Most epistasis occurred between complementary loci, suggesting that grain yield components were associated more with multilocus genotypes than with specific alleles at individual loci. Overdominance was also an important property of most loci associated with heterosis, particularly for panicles per plant and grains per panicle. Two independent groups of genes appeared to affect grain weight: one showing primarily nonadditive gene action explained 62.1% of the heterotic variation of the trait, and the other exhibiting only additive gene action accounted for 28.1% of the total trait variation of the F1 mean values. We found no evidence suggesting that pseudooverdominance from the repulsive linkage of completely or partially dominant QTL for yield components resulted in the overdominant QTL for grain yield. Pronounced overdominance resulting from epistasis expressed by multilocus genotypes appeared to explain the long-standing dilemma of how inbreeding depression could arise from overdominant genes.

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Some Agro-Physiological Indices, Grain Yield Components and Yield of Field-Grown Maize in Response to Mycorrhiza and Phosphorus Fertilizer

Journal of Crop production and processing ◽

10.18869/acadpub.jcpp.5.18.279 ◽

2016 ◽

Vol 5 (18) ◽

pp. 279-290

Author(s):

J. Hamzei ◽

M. Babaei ◽

◽

Keyword(s):

Grain Yield ◽

Yield Components ◽

Phosphorus Fertilizer ◽

Physiological Indices ◽

Grain Yield Components

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Effect of nitrogen, seeding date and cultivar on oat quality and yield in the eastern Canadian prairies

Canadian Journal of Plant Science ◽

10.4141/p04-044 ◽

2004 ◽

Vol 84 (4) ◽

pp. 1025-1036 ◽

Cited By ~ 21

Author(s):

William E. May ◽

Ramona M. Mohr ◽

Guy P. Lafond ◽

Adrian M. Johnston ◽

F. Craig Stevenson

Keyword(s):

Grain Yield ◽

Avena Sativa ◽

Yield Components ◽

Seed Quality ◽

Kernel Weight ◽

Yield Component ◽

Human Consumption ◽

Seeding Date ◽

N Rates

The proportion of oat (Avena sativa L.) being used for race horses and human consumption has increased over the past 15 yr. The objective of this study was to evaluate the effects of N, seeding date and cultivar on grain yield components, grain yield and grain quality of oat under a direct seeding system. Four N rates, three seeding dates and two cultivars were tested at Indian Head, Melfort, and Canora, SK, and Brandon, MB. Yield was more responsive to increasing N rates from 15 and 80 kg ha-1 when oat was seeded in early May versus early June. Panicles plant-1 was the yield component that accounted for most of the yield increase achieved from increasing rates of N, while kernel weight was the yield component that decreased as the rate of N increased. Physical seed quality decreased (plump seed decreased and thin seed increased) with delayed seeding and greater N fertilizer rates. Nitrogen fertilizer and seeding date had a much larger effect on the quality of CDC Pacer than AC Assiniboia. Combining early seeding, appropriate N fertility and well-adapted cultivars should increase the likelihood of optimizing oat yield and quality necessary for high-value markets. Key words: Avena sativa L., yield components, test weight, lodging, plump seed, thin seed

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Determination of Combining Ability and Heterosis of Grain Yield Components for Maize Mutants Based on Line×Tester Analysis

Asian Journal of Crop Science ◽

10.3923/ajcs.2015.19.33 ◽

2014 ◽

Vol 7 (1) ◽

pp. 19-33 ◽

Cited By ~ 7

Author(s):

D. Ruswandi ◽

J. Supriatna ◽

A.T. Makkulawu ◽

B. Waluyo ◽

H. Marta ◽

...

Keyword(s):

Grain Yield ◽

Combining Ability ◽

Yield Components ◽

On Line ◽

Grain Yield Components

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Effect of a Single Height ( Dw ) Gene of Sorghum on Grain Yield, Grain Yield Components, and Test Weight 1

Crop Science ◽

10.2135/cropsci1965.0011183x000500050002x ◽

1965 ◽

Vol 5 (5) ◽

pp. 385-388 ◽

Cited By ~ 33

Author(s):

A. J. Cassady

Keyword(s):

Grain Yield ◽

Yield Components ◽

Test Weight ◽

Grain Yield Components

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High-resolution mapping of rachis nodes per rachis, a critical determinant of grain yield components in wheat

Theoretical and Applied Genetics ◽

10.1007/s00122-019-03383-4 ◽

2019 ◽

Vol 132 (9) ◽

pp. 2707-2719 ◽

Cited By ~ 6

Author(s):

Kai P. Voss-Fels ◽

Gabriel Keeble-Gagnère ◽

Lee T. Hickey ◽

Josquin Tibbits ◽

Sergej Nagornyy ◽

...

Keyword(s):

High Resolution ◽

Grain Yield ◽

Yield Components ◽

Critical Determinant ◽

High Resolution Mapping ◽

Resolution Mapping ◽

Grain Yield Components

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Variability of grain yield components of some new winter wheat genotypes (Triticum aestivum L.)

Plant Soil and Environment ◽

10.17221/4231-pse ◽

2011 ◽

Vol 48 (No. 5) ◽

pp. 230-235

Author(s):

M. Sabo ◽

M. Bede ◽

Ž.U. Hardi

Keyword(s):

Winter Wheat ◽

Grain Yield ◽

Yield Components ◽

Vegetation Period ◽

Grain Number ◽

Potential Yield ◽

High Positive Correlation ◽

Wheat Genotypes ◽

Grain Number Per Spike ◽

Grain Yield Components

Variability of grain yield components of some new winter wheat genotypes (e.g. Lara, Lenta, Kruna, Fiesta, Perla, and one line of AG-45) was examined. The analysis of grain yield components of these genotypes and the line was undertaken in a two-year research (1997/1998 and 1998/1999) at two different locations. Significant differences among genotypes, locations and research years were established. In the first experimental year (1997/1998) there was a high positive correlation between nearly all components of the grain yield. The most significant correlation was found between the grain number per spike and grain yield. In the second experimental year (1998/1999) the components did not show statistically significant correlation with the grain yield. It seems that the grain yield of examined genotypes depended significantly on the grain number per spike, grain mass per spike, and agroecological conditions during the vegetation period, whereby the potential yield was determined by the interaction among genotypes, location and production year. The biggest differences among examined genotypes of winter wheat were found in the stem height and spike length.

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