Register      Login
Crop and Pasture Science Crop and Pasture Science Society
Plant sciences, sustainable farming systems and food quality
REVIEW (Open Access)

Indirect selection for potential yield in early-generation, spaced plantings of wheat and other small-grain cereals: a review

R. A. Fischer A B and G. J. Rebetzke A
+ Author Affiliations
- Author Affiliations

A CSIRO Agriculture and Food, GPO Box 1700, Canberra, ACT 2601, Australia.

B Corresponding author. Email: tony.fischer@csiro.au

Crop and Pasture Science 69(5) 439-459 https://doi.org/10.1071/CP17409
Submitted: 10 November 2017  Accepted: 10 January 2018   Published: 16 April 2018

Journal compilation © CSIRO 2018 Open Access CC BY-NC-ND

Abstract

Early-generation (e.g. F2–F4) selection for grain yield itself is frustrated in particular by the small amounts of seed available. However, there has long been an interest in traits related to yield and reasonably faithfully expressed in spaced planting arrangements using little seed; these are potentially useful as indirect selection criteria for yield, with the view to increasing genetic progress per unit cost. This subject is revisited in this review, targeting potential yield (yield in the absence of abiotic and biotic stresses) of small-grain cereals.

A brief assessment of current breeding systems for self-pollinated crops such as wheat reveals that all have some stage during which selection among visually acceptable spaced plants has to, or could, be practiced. The relative performance of different genotypes in such spaced plantings is then explored, highlighting interactions arising from intergenotypic competition as well as from the extra space itself. The theory of indirect selection is presented, along with some practical examples. After a brief survey of possible selection traits and developments in high-throughput measurement, harvest index, fruiting efficiency and stomatal conductance (and its surrogates) are chosen for in-depth review. All three traits show promise, especially in the light of possible new ways of reducing the cost of their measurement in early generations. Remote sensing of foliage temperature for the detection of genotypic differences in stomatal conductance makes this clearly the most promising trait for thorough testing in commercial breeding populations. Such traits could be used directly or they could complement genomic selection in early generations.

Additional keywords: leaf permeability, foliage temperature, molecular markers.


References

Abbate PE, Andrade FH, Lazaro L, Bariffi JH, Berardocco HG, Inza VH, Marturano F (1998) Grain yield increase in recent Argentine wheat cultivars. Crop Science 38, 1203–1209.
Grain yield increase in recent Argentine wheat cultivars.Crossref | GoogleScholarGoogle Scholar |

Abbate P, Pontaroli A, Lazaro L, Gutheim F (2013) A method of screening for spike fertility in wheat. The Journal of Agricultural Science 151, 322–330.
A method of screening for spike fertility in wheat.Crossref | GoogleScholarGoogle Scholar |

Acreche MM, Briceño-Felix G, Sanchez JAM, Slafer GA (2008) Physiological bases of genetic gains in Mediterranean bread wheat yield in Spain. European Journal of Agronomy 28, 162–170.
Physiological bases of genetic gains in Mediterranean bread wheat yield in Spain.Crossref | GoogleScholarGoogle Scholar |

Aisawi KAB, Reynolds MP, Singh RP, Foulkes MJ (2015) The physiological basis of the genetic progress in yield potential of CIMMYT spring wheat cultivars from 1966 to 2009. Crop Science 55, 1749–1764.
The physiological basis of the genetic progress in yield potential of CIMMYT spring wheat cultivars from 1966 to 2009.Crossref | GoogleScholarGoogle Scholar |

Allard RW (1960) ‘Principles of plant breeding.’ (John Wiley & Sons: New York)

Amani I, Fischer RA, Reynolds MP (1996) Canopy temperature depression associated with yield of spring wheat cultivars in a hot climate. Journal of Agronomy & Crop Science 176, 119–129.
Canopy temperature depression associated with yield of spring wheat cultivars in a hot climate.Crossref | GoogleScholarGoogle Scholar |

Araus JL, Cairns JE (2014) Field high-throughput phenotyping: the new crop breeding frontier. Trends in Plant Science 19, 52–61.
Field high-throughput phenotyping: the new crop breeding frontier.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC3sXhs1CrtbjL&md5=280628e0fdc824e32e3213d18f78e6b5CAS |

Araus JL, Slafer GA, Reynolds MP, Royo C (2002) Plant breeding and drought in C3 cereals: What should we breed for? Annals of Botany 89, 925–940.
Plant breeding and drought in C3 cereals: What should we breed for?Crossref | GoogleScholarGoogle Scholar |

Austin RB (1980) Physiological limitations to cereal yields and ways of reducing them by breeding. In ‘Opportunities for increasing crop yields’. (Eds RG Hurd, PV Biscoe, C Dennis) pp. 3–19. (Pitman: London)

Basnayake J, Jackson PA, Inman-Bamber NG, Lakshmanan P (2015) Sugarcane for water-limited environments. Variation in stomatal conductance and its genetic correlation with crop productivity. Journal of Experimental Botany 66, 3945–3958.
Sugarcane for water-limited environments. Variation in stomatal conductance and its genetic correlation with crop productivity.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC28Xkt1KlsL0%3D&md5=4c27fbcb3b879f6b0853328b9dc6993dCAS |

Beche E, Benin G, Lemes da Silva C, Munaro LB, Marchese JA (2014) Genetic gain in yield and changes associated with physiological traits in Brazilian wheat during the 20th century. European Journal of Agronomy 61, 49–59.
Genetic gain in yield and changes associated with physiological traits in Brazilian wheat during the 20th century.Crossref | GoogleScholarGoogle Scholar |

Bernardo R (2003) On the effectiveness of early generation selection in self-pollinated crops. Crop Science 43, 1558–1560.
On the effectiveness of early generation selection in self-pollinated crops.Crossref | GoogleScholarGoogle Scholar |

Bernardo R (2016) Bandwagons I, too, have known. Theoretical and Applied Genetics 129, 2323–2332.
Bandwagons I, too, have known.Crossref | GoogleScholarGoogle Scholar |

Berry PM, Sylvester-Bradley R, Berry S (2007) Ideotype design for lodging-proof wheat. Euphytica 154, 165–179.
Ideotype design for lodging-proof wheat.Crossref | GoogleScholarGoogle Scholar |

Bhatt GM (1977) Response to two-way selection for harvest index in two wheat (Triticum aestivum L.) crosses. Australian Journal of Agricultural Research 28, 29–36.
Response to two-way selection for harvest index in two wheat (Triticum aestivum L.) crosses.Crossref | GoogleScholarGoogle Scholar |

Bhatt GM (1980) Early generation criteria for yield selection in wheat. Journal of the Australian Institute of Agricultural Science 46, 14–22.

Bhatt GM, Derera NF (1978) Selection for harvest index among near-homozygous lines of wheat. Journal of the Australian Institute of Agricultural Science 44, 111–112.

Blum A, Mayer J, Gozlan G (1982) Infrared thermal sensing of plant canopies as a screening technique for dehydration avoidance in wheat. Field Crops Research 5, 137–146.
Infrared thermal sensing of plant canopies as a screening technique for dehydration avoidance in wheat.Crossref | GoogleScholarGoogle Scholar |

Bonnett DG, Rebetzke GJ, Spielmeyer W (2005) Strategies for efficient implementation of molecular markers in wheat breeding. Molecular Breeding 15, 75–85.
Strategies for efficient implementation of molecular markers in wheat breeding.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD2MXhslyrsrs%3D&md5=9bf60855a5db53e45fece75ad1b2eee6CAS |

Borghi B, Accerbi M, Corbellini M (1998) Response to early generation selection for grain yield and harvest index in bread wheat (T. aestivum L.). Plant Breeding 117, 13–18.
Response to early generation selection for grain yield and harvest index in bread wheat (T. aestivum L.).Crossref | GoogleScholarGoogle Scholar |

Bos I, Caligari P (1995) ‘Selection methods in plant breeding.’ (Chapman Hall: London)

Brennan JP, Condon AG, Van Ginkel M, Reynolds MP (2007) An economic assessment of the use of physiological selection for stomatal aperture-related traits in the CIMMYT wheat breeding programme. The Journal of Agricultural Science 145, 187–194.
An economic assessment of the use of physiological selection for stomatal aperture-related traits in the CIMMYT wheat breeding programme.Crossref | GoogleScholarGoogle Scholar |

Brim CA (1966) A modified pedigree method of selection in soybeans. Crop Science 6, 220
A modified pedigree method of selection in soybeans.Crossref | GoogleScholarGoogle Scholar |

Christopher JT, Veyradier M, Borrell AK, Harvey G, Fletcher S, Chenu K (2014) Phenotyping novel stay-green traits to capture genetic variation in senescence dynamics. Functional Plant Biology 41, 1035–1048.
Phenotyping novel stay-green traits to capture genetic variation in senescence dynamics.Crossref | GoogleScholarGoogle Scholar |

CIMMYT (1977) Physiology. CIMMYT Report on Wheat Improvement. pp. 106–118. CIMMYT, Mexico, DF.

CIMMYT (1978) Physiology. CIMMYT Report on Wheat Improvement. pp. 117–128. CIMMYT, Mexico, DF.

Clarke JM (1997) Inheritance of stomatal conductance in a durum wheat cross. Canadian Journal of Plant Science 77, 623–625.
Inheritance of stomatal conductance in a durum wheat cross.Crossref | GoogleScholarGoogle Scholar |

Clement JD, Constable GA, Stiller WN, Liu SM (2015) Early generation selection strategies for breeding better combinations of cotton yield and fibre quality. Field Crops Research 172, 145–152.
Early generation selection strategies for breeding better combinations of cotton yield and fibre quality.Crossref | GoogleScholarGoogle Scholar |

Condon AG, Richards RA, Farquhar GD (1987) Carbon isotope discrimination is positively correlated with grain yield and dry matter production in field-grown wheat. Crop Science 27, 996–1001.
Carbon isotope discrimination is positively correlated with grain yield and dry matter production in field-grown wheat.Crossref | GoogleScholarGoogle Scholar |

Condon AG, Reynolds MP, Brennan J, van Ginkel M, Trethowan R, Rebetzke GJ, Bonnett DG, Richards RA, Farquhar GD (2008) Stomatal aperture related traits and yield potential in bread wheat. In ‘Proceedings CIMMYT Wheat Yield Potential Symposium’. (Eds MP Reynolds, PR Hobbs, R Ortiz, J Pietragalla, HJ Braun) pp. 126–133. (CIMMYT: Mexico, DF)

Cooper M, Messina CD, Podlich D, Totir LR, Baumgarten A, Hausmann NJ, Wright D, Graham G (2014) Predicting the future of plant breeding: complementing empirical evaluation with genetic prediction. Crop & Pasture Science 65, 311–336.
Predicting the future of plant breeding: complementing empirical evaluation with genetic prediction.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC2cXotVKnsbk%3D&md5=7ec300b8e9583c880cda7e7a7d2d03d8CAS |

Crossa J, Pérez-Rodriguez P, Cuevas J, Montesinos-López O, Jarquín D, De Los Campos G, Burgueño J, Comacho-González JM, Pérez-Elizalde S, Beyene Y, Dreisigacker S, Singh R, Zhang X, Gowda M, Roorkiwal M, Rutkoski J, Varshney RK (2017) Genomic selection in plant breeding: Methods, models, and perspectives. Trends in Plant Science 22, 961–975.

DePauw RM, Shebetski LH (1973) An evaluation of an early generation yield testing procedure in Triticum aestivum. Canadian Journal of Plant Science 53, 465–470.
An evaluation of an early generation yield testing procedure in Triticum aestivum.Crossref | GoogleScholarGoogle Scholar |

Donald CM (1963) Competition among crop and pasture plants. Advances in Agronomy 15, 1–118.
Competition among crop and pasture plants.Crossref | GoogleScholarGoogle Scholar |

Donald CM (1968) The breeding of crop ideotypes. Euphytica 17, 385–403.
The breeding of crop ideotypes.Crossref | GoogleScholarGoogle Scholar |

Donald CM (1981) Competitive plants, communal plants and yield in wheat crops. In ‘Wheat science – today and tomorrow’. (Eds LT Evans, WJ Peacock) pp. 223–247. (Cambridge University Press: Cambridge, UK)

Donald CM, Hamblin J (1976) The biological yield and harvest index of cereals as agronomic and plant breeding criteria. Advances in Agronomy 28, 361–405.
The biological yield and harvest index of cereals as agronomic and plant breeding criteria.Crossref | GoogleScholarGoogle Scholar |

Elía M, Savin R, Slafer GA (2016) Fruiting efficiency in wheat: physiological aspects and genetic variation among modern cultivars. Field Crops Research 191, 83–90.
Fruiting efficiency in wheat: physiological aspects and genetic variation among modern cultivars.Crossref | GoogleScholarGoogle Scholar |

Ellison FW, Latter BDH, Anttonen T (1985) Optimum regimnes for selection for grain yield and harvest index in spring wheat. Euphytica 34, 625–640.
Optimum regimnes for selection for grain yield and harvest index in spring wheat.Crossref | GoogleScholarGoogle Scholar |

Falconer DS, Mackay TFC (1997) ‘Introduction to quantitative genetics.’ 4th edn (Addison Wesley Longman: Harlow, UK)

Farquhar GD, Richards RA (1984) Isotopic composition of plant carbon correlates with water-use efficiency. Australian Journal of Plant Physiology 11, 539–552.
Isotopic composition of plant carbon correlates with water-use efficiency.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaL2MXhtFSju7w%3D&md5=25eb169595c9295df4b6c0fc2e874f88CAS |

Fasoula DA (1990) Correlations between auto-, allo- and nil-competition and their implications in plant breeding. Euphytica 50, 57–62.
Correlations between auto-, allo- and nil-competition and their implications in plant breeding.Crossref | GoogleScholarGoogle Scholar |

Fasoulas A (1981) ‘Principles and methods of plant breeding.’ Publication No. 11. (Aristotle University: Thessaloniki, Greece)

Fiorani F, Schurr U (2013) Future scenarios for plant phenotyping. Annual Review of Plant Biology 64, 267–291.
Future scenarios for plant phenotyping.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC3sXosFSktLw%3D&md5=55f5687aba95a890aab5fb92ca49fef4CAS |

Fischer RA (1978) Are your results confounded by intergenotypic competition? In ‘Proceedings 5th International Wheat Genetics Symposium’. Vol. II. (Ed. S Ramanjam) pp. 767–777. (Indian Society of Genetics and Plant Breeding: New Delhi)

Fischer RA (2011) Wheat physiology: a review of recent developments. Crop & Pasture Science 62, 95–114.
Wheat physiology: a review of recent developments.Crossref | GoogleScholarGoogle Scholar |

Fischer RA (2015) Definitions and determination of crop yield, yield gaps and of rates of change. Field Crops Research 182, 9–18.
Definitions and determination of crop yield, yield gaps and of rates of change.Crossref | GoogleScholarGoogle Scholar |

Fischer RA, Edmeades GO (2010) Breeding and cereal yield progress. Crop Science 50, S85–S98.
Breeding and cereal yield progress.Crossref | GoogleScholarGoogle Scholar |

Fischer RA, Kertesz Z (1976) Harvest index in spaced plant populations and grain weight in microplots as indicators of yielding ability in spring wheat. Crop Science 16, 55–59.
Harvest index in spaced plant populations and grain weight in microplots as indicators of yielding ability in spring wheat.Crossref | GoogleScholarGoogle Scholar |

Fischer RA, Quail KJ (1990) The effect of major dwarfing genes on yield potential in spring wheats. Euphytica 46, 51–56.
The effect of major dwarfing genes on yield potential in spring wheats.Crossref | GoogleScholarGoogle Scholar |

Fischer RA, Stockman YM (1986) Increased kernel number in Norin10-derived dwarf wheat: evaluation of the cause. Australian Journal of Plant Physiology 13, 767–784.
Increased kernel number in Norin10-derived dwarf wheat: evaluation of the cause.Crossref | GoogleScholarGoogle Scholar |

Fischer RA, Aguilar I, Maurer R, Rivas S (1976) Density and row spacing effects on irrigated short wheats at low latitude. The Journal of Agricultural Science 87, 137–147.
Density and row spacing effects on irrigated short wheats at low latitude.Crossref | GoogleScholarGoogle Scholar |

Fischer RA, Sanchez M, Syme JR (1977) Pressure chamber and air flow porometer for rapid field indication of water status and stomatal condition in wheat. Experimental Agriculture 13, 341–352.
Pressure chamber and air flow porometer for rapid field indication of water status and stomatal condition in wheat.Crossref | GoogleScholarGoogle Scholar |

Fischer RA, Bidinger F, Syme JR, Wall PC (1981) Leaf photosynthesis, leaf permeability, crop growth, and yield of short spring wheat genotypes under irrigation. Crop Science 21, 367–373.
Leaf photosynthesis, leaf permeability, crop growth, and yield of short spring wheat genotypes under irrigation.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaL3MXksFyhu7g%3D&md5=d3fd10b0a2edd2e33cfe134495272d2aCAS |

Fischer RA, O’Brien L, Quail KJ (1989) Early generation selection in wheat. II Grain quality. Australian Journal of Agricultural Research 40, 1135–1142.
Early generation selection in wheat. II Grain quality.Crossref | GoogleScholarGoogle Scholar |

Fischer RA, Rees D, Sayre KD, Lu Z, Condon AG, Larque Saavedra A (1998) Wheat yield progress is associated with higher stomatal conductance and photosynthetic rate, and cooler canopies. Crop Science 38, 1467–1475.
Wheat yield progress is associated with higher stomatal conductance and photosynthetic rate, and cooler canopies.Crossref | GoogleScholarGoogle Scholar |

Fischer RA, Sayre KD, Ortiz Monasterio I (2005) The effect of raised bed planting on irrigated wheat yield as influenced by variety and row spacing. In ‘Evaluation and performance of permanent raised bed cropping systems in Asia, Australia and Mexico’. ACIAR Proceedings No. PR121. (Eds CA Roth, RA Fischer, CA Meisner) pp. 1–11. (ACIAR: Canberra, ACT)

Fischer RA, Byerlee D, Edmeades GO (2014) ‘Crop yields and global food security: will yield increase continue to feed the world?’ Monograph No. 158. (Australian Centre of International Agricultural Research: Canberra) Available at: http://aciar.gov.au/publication/mn158

Frey KJ (1965) The utility of hill plots in oat research. Euphytica 14, 196–208.
The utility of hill plots in oat research.Crossref | GoogleScholarGoogle Scholar |

García GA, Hasan AK, Puhl LE, Reynolds MP, Calderini DF, Miralles DJ (2013) Grain yield potential strategies in an elite wheat double-haploid population grown in contrasting environments. Crop Science 53, 2577–2587.
Grain yield potential strategies in an elite wheat double-haploid population grown in contrasting environments.Crossref | GoogleScholarGoogle Scholar |

García GA, Serrago RA, Gonzalez FG, Slafer GA, Reynolds MP, Miralles DJ (2014) Wheat grain number: Identification of favourable physiological traits in an elite doubled-haploid population. Field Crops Research 168, 126–134.
Wheat grain number: Identification of favourable physiological traits in an elite doubled-haploid population.Crossref | GoogleScholarGoogle Scholar |

Ghanem ME, Marrou H, Sinclair TR (2015) Physiological phenotyping of plants for crop improvement. Trends in Plant Science 20, 139–144.
Physiological phenotyping of plants for crop improvement.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC2cXitVeis7bO&md5=73c55f40cffc0367e224694b3da9d97eCAS |

Giunta F, Motzo R, Pruneddu G (2007) Trends since 1900 in yield potential of Italian-bred durum wheat cultivars. European Journal of Agronomy 27, 12–24.
Trends since 1900 in yield potential of Italian-bred durum wheat cultivars.Crossref | GoogleScholarGoogle Scholar |

Giunta F, Motzo R, Pruneddu G (2008) Has long-term selection for yield in durum wheat also induced changes in leaf and canopy traits. Field Crops Research 106, 68–76.
Has long-term selection for yield in durum wheat also induced changes in leaf and canopy traits.Crossref | GoogleScholarGoogle Scholar |

Hamblin J, Donald CM (1974) The relationships between plant form, competitive ability and grain yield in a barley cross. Euphytica 23, 535–542.
The relationships between plant form, competitive ability and grain yield in a barley cross.Crossref | GoogleScholarGoogle Scholar |

Hamblin J, Rosielle AA (1978) Effect of intergenotypic competition on genetic parameter estimation. Crop Science 18, 51–54.
Effect of intergenotypic competition on genetic parameter estimation.Crossref | GoogleScholarGoogle Scholar |

Hazel LN, Lush JN (1942) The efficiency of three methods of selection. The Journal of Heredity 33, 393–399.
The efficiency of three methods of selection.Crossref | GoogleScholarGoogle Scholar |

Jackson P, McRae TA (2001) Selection of sugarcane clones in small plots: effects of plot size and selection criteria. Crop Science 41, 315–322.
Selection of sugarcane clones in small plots: effects of plot size and selection criteria.Crossref | GoogleScholarGoogle Scholar |

Jackson P, Robertson M, Cooper M, Hammer G (1996) The role of physiological understanding in plant breeding; from a breeding perspective. Field Crops Research 49, 11–37.
The role of physiological understanding in plant breeding; from a breeding perspective.Crossref | GoogleScholarGoogle Scholar |

Jackson RD, Reginato RJ, Idso SB (1977) Wheat canopy temperature–practical tool for evaluating water requirements. Water Resources Research 13, 651–656.
Wheat canopy temperature–practical tool for evaluating water requirements.Crossref | GoogleScholarGoogle Scholar |

Jennings PR, Herrera RM (1968) Studies on competition in rice 2. Competition in segregating populations. Evolution 22, 332–336.
Studies on competition in rice 2. Competition in segregating populations.Crossref | GoogleScholarGoogle Scholar |

Jones HG, Vaughan RA (2010) ‘Remote sensing of vegetation.’ (Oxford University Press: Oxford, UK)

Kawano K, Tanaka A (1967) Studies on the competitive ability of rice plant in population. Journal of the Faculty of Agriculture, Hokkaido University 55, 339–361.

Kawano K, Gonzalez H, Lucena M (1974) Intraspecific competition, competition with weeds, and spacing response in rice. Crop Science 14, 841–845.
Intraspecific competition, competition with weeds, and spacing response in rice.Crossref | GoogleScholarGoogle Scholar |

Knott DRK (1979) Selection for yield in wheat breeding. Euphytica 28, 37–40.
Selection for yield in wheat breeding.Crossref | GoogleScholarGoogle Scholar |

Kramer Th, van Ooijen JW, Spitters CJT (1982) Selection for yield in small plots of spring wheat. Euphytica 31, 549–564.
Selection for yield in small plots of spring wheat.Crossref | GoogleScholarGoogle Scholar |

Lawrence MJ, Senadhira D (1998) Quantitative genetics of rice IV. A breeding strategy. Field Crops Research 55, 275–281.
Quantitative genetics of rice IV. A breeding strategy.Crossref | GoogleScholarGoogle Scholar |

Lopes MS, Reynolds MP (2011) Drought adaptive traits and wide adaptation in elite lines derived from resynthesized hexaploid wheat. Crop Science 51, 1617–1626.
Drought adaptive traits and wide adaptation in elite lines derived from resynthesized hexaploid wheat.Crossref | GoogleScholarGoogle Scholar |

Lu ZM, Percy RG, Qualset CO, Zeiger E (1998) Stomatal conductance predicts yields in irrigated cotton and bread wheat grown at high temperatures. Journal of Experimental Botany 49, 453–460.
Stomatal conductance predicts yields in irrigated cotton and bread wheat grown at high temperatures.Crossref | GoogleScholarGoogle Scholar |

Marshall DR (1991) Alternative approaches and perspectives in breeding for higher yields. Field Crops Research 26, 171–190.
Alternative approaches and perspectives in breeding for higher yields.Crossref | GoogleScholarGoogle Scholar |

Martino DL, Abbate PE, Cendoya MG, Gutheim F, Mirabella NE, Pontaroli AC (2015) Wheat spike fertility: inheritance and relationship with spike yield components in early generations. Plant Breeding 134, 264–270.
Wheat spike fertility: inheritance and relationship with spike yield components in early generations.Crossref | GoogleScholarGoogle Scholar |

Mirabella NE, Abbate PE, Ramirez IA, Pontaroli AC (2016) Genetic variation for wheat spike fertility and early breeding materials. The Journal of Agricultural Science 154, 13–22.
Genetic variation for wheat spike fertility and early breeding materials.Crossref | GoogleScholarGoogle Scholar |

Miri HR (2009) Grain yield and morpho-physiological changes from 60 years of genetic improvement of wheat in Iran. Experimental Agriculture 45, 149–163.
Grain yield and morpho-physiological changes from 60 years of genetic improvement of wheat in Iran.Crossref | GoogleScholarGoogle Scholar |

Mitchell JW, Baker RJ, Knott DR (1982) Evaluation of honeycomb selection for single plant yield in durum wheat. Crop Science 22, 840–843.
Evaluation of honeycomb selection for single plant yield in durum wheat.Crossref | GoogleScholarGoogle Scholar |

Moreno-Ramos OH, Rodriguez-Casas J, Johnson D, Thompson TL (2004) Wheat response to population and bed spacing in northwest Mexico. Cereal Research Communications 32, 273–279.

Nass HG (1980) Harvest index as a selection criterion for grain yield in 2 spring wheat crosses grown at 2 population densities. Canadian Journal of Plant Science 60, 1141–1146.

Olivares-Villegas JJ, Reynolds MP, McDonald GK (2007) Drought-adaptive traits in the Seri/Babax hexaploid wheat population. Functional Plant Biology 34, 189–203.
Drought-adaptive traits in the Seri/Babax hexaploid wheat population.Crossref | GoogleScholarGoogle Scholar |

Pask AJD, Pietragalla J, Mullan DM, Reynolds MP (Eds) (2012) ‘Physiological breeding Vol. II: A field guide to wheat phenotyping.’ (CIMMYT: Mexico, DF)

Pedró A, Savin R, Parry MAJ, Slafer GA (2012a) Selection for high grain number per unit stem length through four generations from mutants in a durum wheat population to increase yields of individual plants and crops. Field Crops Research 129, 59–70.
Selection for high grain number per unit stem length through four generations from mutants in a durum wheat population to increase yields of individual plants and crops.Crossref | GoogleScholarGoogle Scholar |

Pedró A, Savin R, Slafer GA (2012b) Crop productivity as related to single-plant traits at key phenological stages in durum wheat. Field Crops Research 138, 42–51.
Crop productivity as related to single-plant traits at key phenological stages in durum wheat.Crossref | GoogleScholarGoogle Scholar |

Piepho H-P, Möhring J (2007) Computing heritability and selection response from unbalanced plant breeding trials. Genetics 177, 1881–1888.
Computing heritability and selection response from unbalanced plant breeding trials.Crossref | GoogleScholarGoogle Scholar |

Pietragalla J, Pask A (2012) Grain yield and yield components. In ‘Physiological breeding Vol II: A field guide to wheat phenotyping’. Ch. 18. (Eds AJD Pask, J Pietragalla, DM Mullan, MP Reynolds) pp. 95–103. (CIMMYT: Mexico, DF)

Pszczola M, Veerkamp RF, de Haas Y, Wall E, Strabel T, Calus MPL (2013) Effect of predictor traits on accuracy of genomic breeding values for feed intake based on a limited cow reference population. Animal 7, 1759–1768.
Effect of predictor traits on accuracy of genomic breeding values for feed intake based on a limited cow reference population.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC3sXhsFOisb%2FE&md5=6e8d9af96d617d5794d0677df96846f2CAS |

Puckridge DW, Donald CM (1967) Competition among wheat plants sown at a wide range of densities. Australian Journal of Agricultural Research 18, 193–211.
Competition among wheat plants sown at a wide range of densities.Crossref | GoogleScholarGoogle Scholar |

Quail KJ, Fischer RA, Woods JT (1989) Early generation selection in wheat. I. Yield potential. Australian Journal of Agricultural Research 40, 1117–1133.
Early generation selection in wheat. I. Yield potential.Crossref | GoogleScholarGoogle Scholar |

Rebetzke GJ, Read JJ, Barbour MM, Condon AG, Rawson HM (2000) A hand-held porometer for rapid assessment of leaf conductance in wheat. Crop Science 40, 277–280.
A hand-held porometer for rapid assessment of leaf conductance in wheat.Crossref | GoogleScholarGoogle Scholar |

Rebetzke GJ, Condon AG, Richards RA, Farquhar GD (2002) Selection for reduced carbon isotope discrimination increases aerial biomass and grain yield of rainfed bread wheat. Crop Science 42, 739–745.
Selection for reduced carbon isotope discrimination increases aerial biomass and grain yield of rainfed bread wheat.Crossref | GoogleScholarGoogle Scholar |

Rebetzke GJ, Condon AG, Richards RA, Farquhar GD (2003) Gene action for leaf conductance in three wheat crosses. Australian Journal of Agricultural Research 54, 381–397.
Gene action for leaf conductance in three wheat crosses.Crossref | GoogleScholarGoogle Scholar |

Rebetzke GJ, Botwright TL, Moore CS, Richards RA, Condon AG (2004) Genotypic variation in specific leaf area for genetic improvement of early vigour in wheat. Field Crops Research 88, 179–189.
Genotypic variation in specific leaf area for genetic improvement of early vigour in wheat.Crossref | GoogleScholarGoogle Scholar |

Rebetzke GJ, Rattey AR, Farquhar GD, Richards RA, Condon AG (2013) Genomic regions for canopy temperature and their genetic association with stomatal conductance and grain yield in wheat. Functional Plant Biology 40, 14–33.
Genomic regions for canopy temperature and their genetic association with stomatal conductance and grain yield in wheat.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC38XhvVertLnI&md5=d10f2ccd2a030bf00171f4423c8d9c89CAS |

Rebetzke GJ, Fischer RA, van Herwaarden AF, Bonnett DG, Chenu K, Rattey AR, Fettell NA (2014) Plot size matters: interference from intergenotypic competition in plant phenotyping studies. Functional Plant Biology 41, 107–118.
Plot size matters: interference from intergenotypic competition in plant phenotyping studies.Crossref | GoogleScholarGoogle Scholar |

Rebetzke GJ, Boonee DG, Reynolds MP (2016) Awns reduce grain number to increase grain size and harvestable yield in irrigated and rainfed spring wheat. Journal of Experimental Botany 67, 2573–2586.
Awns reduce grain number to increase grain size and harvestable yield in irrigated and rainfed spring wheat.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC28XhsF2ntbbI&md5=289edd89a0632c7692309a6504636fa3CAS |

Rees D, Sayre KD, Acevedo E, Nava Sanchez T, Lu Z, Zeiger E, Limon A (1993) Canopy temperature in wheat: relationships of yield and potential as a technique for early generation selection. Wheat Special Report No. 10. CIMMYT, Mexico, DF.

Reynolds M, Langridge P (2016) Physiological breeding. Current Opinion in Plant Biology 31, 162–171.
Physiological breeding.Crossref | GoogleScholarGoogle Scholar |

Reynolds M, Acevedo E, Sayre K, Fischer R (1994) Yield potential in modern wheat varieties: Its association with a less competitive ideotype. Field Crops Research 37, 149–160.
Yield potential in modern wheat varieties: Its association with a less competitive ideotype.Crossref | GoogleScholarGoogle Scholar |

Reynolds MP, Rajaram S, Sayre KD (1999) Physiological and genetic changes in irrigated wheat in post-Green Revolution period and approaches for meeting projected global demand. Crop Science 39, 1611–1621.
Physiological and genetic changes in irrigated wheat in post-Green Revolution period and approaches for meeting projected global demand.Crossref | GoogleScholarGoogle Scholar |

Reynolds MP, Pask AJD, Mullan DM (Eds) (2012) ‘Physiological breeding Vol I: Interdisciplinary approaches to improve crop adaptation.’ (CIMMYT: Mexico, DF)

Richards RA (1992) The effect of dwarfing genes in spring wheat in dry environments. I. Agronomic characteristics. Australian Journal of Agricultural Research 43, 517–527.
The effect of dwarfing genes in spring wheat in dry environments. I. Agronomic characteristics.Crossref | GoogleScholarGoogle Scholar |

Roche D (2015) Stomatal conductance is essential for higher yield potential. Critical Reviews in Plant Sciences 34, 429–453.
Stomatal conductance is essential for higher yield potential.Crossref | GoogleScholarGoogle Scholar |

Rutkoski J, Poland J, Mondal S, Autrique E, Gonzalez Perez L, Crossa J, Reynolds MP, Singh R (2016) Canopy temperature and vegetation indices from high-throughput phenotyping improve accuracy of pedigree and genomic selection for grain yield in wheat. G3–Genes Genomes Genetics 6, 2799
Canopy temperature and vegetation indices from high-throughput phenotyping improve accuracy of pedigree and genomic selection for grain yield in wheat.Crossref | GoogleScholarGoogle Scholar |

Sadras VO, Lawson C (2011) Genetic gain in yield and associated changes in phenotype, trait plasticity and competitive ability of South Australian wheat varieties released between 1958 and 2007. Crop & Pasture Science 62, 533–549.
Genetic gain in yield and associated changes in phenotype, trait plasticity and competitive ability of South Australian wheat varieties released between 1958 and 2007.Crossref | GoogleScholarGoogle Scholar |

Sharma RC, Smith EL (1986) Selection for high and low harvest index in three winter wheat populations. Crop Science 26, 1147–1150.
Selection for high and low harvest index in three winter wheat populations.Crossref | GoogleScholarGoogle Scholar |

Sharma RC, Smith EL (1987) Effect of seeding rates on harvest index, grain yield, and biomass yield in winter cereals. Crop Science 27, 528–531.
Effect of seeding rates on harvest index, grain yield, and biomass yield in winter cereals.Crossref | GoogleScholarGoogle Scholar |

Sharma RC, Smith EL, McNew RW (1987) Stability of harvest index and grain yield in wheat. Crop Science 27, 104–108.
Stability of harvest index and grain yield in wheat.Crossref | GoogleScholarGoogle Scholar |

Sharma RC, Smith EL, McNew RW (1991) Combining ability analysis for harvest index in winter wheat. Euphytica 55, 229–234.
Combining ability analysis for harvest index in winter wheat.Crossref | GoogleScholarGoogle Scholar |

Shearman VJ, Sylvester-Bradley R, Scott RK, Foulkes MJ (2005) Physiological processes associated with yield progress in the UK. Crop Science 45, 175–185.

Shimshi D, Ephrat E (1975) Stomatal behaviour of wheat cultivars in relation to their transpiration, photosynthesis and yield. Agronomy Journal 67, 326–331.
Stomatal behaviour of wheat cultivars in relation to their transpiration, photosynthesis and yield.Crossref | GoogleScholarGoogle Scholar |

Siddique KHM, Whan BR (1994) Ear:stem ratios in breeding populations of wheat: significance for yield improvement. Euphytica 73, 241–254.
Ear:stem ratios in breeding populations of wheat: significance for yield improvement.Crossref | GoogleScholarGoogle Scholar |

Simmonds NW (1996) Family selection in plant breeding. Euphytica 90, 201–208.
Family selection in plant breeding.Crossref | GoogleScholarGoogle Scholar |

Singh RP, Rajaram S, Miranda A, Huerta-Espinoza J, Autrique E (1998) Comparison of two crossing and four selection schemes for yield, yield traits, and slow rusting resistance to leaf rust in wheat. Euphytica 100, 35–43.
Comparison of two crossing and four selection schemes for yield, yield traits, and slow rusting resistance to leaf rust in wheat.Crossref | GoogleScholarGoogle Scholar |

Slafer GA, Andrade F (1993) Physiological attributes related to the generation of grain-yield in bread wheat cultivars released at different eras. Field Crops Research 31, 351–367.
Physiological attributes related to the generation of grain-yield in bread wheat cultivars released at different eras.Crossref | GoogleScholarGoogle Scholar |

Slafer GA, Elia M, Savin R, Garcia GA, Terrile II, Ferrante A, Miralles DJ, Gonzalez FG (2015) Fruiting efficiency: an alternative trait to further rise wheat yield. Food and Energy Security 4, 92–109.
Fruiting efficiency: an alternative trait to further rise wheat yield.Crossref | GoogleScholarGoogle Scholar |

Sneep J (1977) Selection for yield in early generations of self-fertilizing crops. Euphytica 26, 27–30.
Selection for yield in early generations of self-fertilizing crops.Crossref | GoogleScholarGoogle Scholar |

Spitters CJ, Kramer T (1984) Changes in relative growth rate with plant ontogeny in spring wheat genotypes grown as isolated plants. Euphytica 43, 833–847.

Sukumaran S, Reynolds MP, Lopes MS, Crossa J (2015) Genome-wide association study for adaptation to agronomic plant density: A component of high yield potential in spring wheat. Crop Science 55, 2609–2619.
Genome-wide association study for adaptation to agronomic plant density: A component of high yield potential in spring wheat.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC28XnvVKksb0%3D&md5=1b2ee4c3378bd61401b7b8e12064ffdbCAS |

Syme JR (1972) Single plant characters as a measure of field plot performance of wheat cultivars. Australian Journal of Agricultural Research 23, 753–760.
Single plant characters as a measure of field plot performance of wheat cultivars.Crossref | GoogleScholarGoogle Scholar |

Takeda K, Frey KJ (1985) Increasing grain yield of oats by independent culling for harvest index and vegetative growth index or unit straw weight. Euphytica 34, 33–41.
Increasing grain yield of oats by independent culling for harvest index and vegetative growth index or unit straw weight.Crossref | GoogleScholarGoogle Scholar |

Tanger P, Klassen S, Mojica JP, Lovell JT, Moyers BT, Baraoidan M, Naredo MEB, McNally KL, Poland J, Bush DR, Leung H, Leach JE, McKay JK (2017) Field-based high throughput phenotyping rapidly identifies genomic regions controlling yield components in rice. Scientific Reports 7, 42839
Field-based high throughput phenotyping rapidly identifies genomic regions controlling yield components in rice.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC2sXjtlygsLY%3D&md5=f147156462924d7ce255e93f0baf97e7CAS |

Terrile II, Miralles DJ, Gonzalez FC (2017) Fruiting efficiency in wheat (Triticum aestivum L.): Trait response to different growing conditions and its relation to spike dry weight at anthesis and grain weight at harvest. Field Crops Research 201, 86–96.
Fruiting efficiency in wheat (Triticum aestivum L.): Trait response to different growing conditions and its relation to spike dry weight at anthesis and grain weight at harvest.Crossref | GoogleScholarGoogle Scholar |

Thakare RB, Qualset CO (1978) Empirical evaluations of single-plant and family selection strategies in wheat. Crop Science 18, 115–118.
Empirical evaluations of single-plant and family selection strategies in wheat.Crossref | GoogleScholarGoogle Scholar |

Tokatlidis IS, Xynias IN, Tsialtas JT, Papadopoulos II (2006) Single-plant selection at ultra-low density to improve stability of a bread wheat cultivar. Crop Science 46, 90–97.
Single-plant selection at ultra-low density to improve stability of a bread wheat cultivar.Crossref | GoogleScholarGoogle Scholar |

Vadez V, Kholova J, Medina S, Kakkera A, Anderberg H (2014) Transpiration efficiency: new insights into an old story. Journal of Experimental Botany 65, 6141–6153.
Transpiration efficiency: new insights into an old story.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC2MXitl2gsb8%3D&md5=7c0d0eeea8a7e1685759dd0e470bfe95CAS |

van Ginkel M, Ortiz R (2017) Cross the best with the best, and select the best: HELP in breeding selfing crops. Crop Science 58, 1–14.

van Ginkel M, Reynolds MP, Trethowan RT, Hernandez E (2004) Can canopy temperature depression measurements help breeders in selecting for yield in wheat under irrigated production conditions? In ‘New directions for a diverse planet. Proceedings 4th International Crop Science Congress’. (Eds RA Fischer et al.) pp. 3.4.6. (The Regional Institute: Gosford, NSW)

Wallace DH, Yan W (2000) ‘Plant breeding and whole-system crop physiology.’ (CAB International: Wallingford, UK)

Wang H, van Eeuwijk FA (2014) A new method to infer causal phenotype networks using QTL and phenotypic information. PLoS One 9, e103997
A new method to infer causal phenotype networks using QTL and phenotypic information.Crossref | GoogleScholarGoogle Scholar |

Wang J, van Ginkel M, Podlich D, Ye G, Trethowan R, Pfeiffer W, DeLacy IH, Cooper M, Rajaram S (2003) Comparison of two breeding strategies by computer simulation. Crop Science 43, 1764–1773.
Comparison of two breeding strategies by computer simulation.Crossref | GoogleScholarGoogle Scholar |

Watson A, Ghosh S, Williams MJ, Cuddy WS, Simmonds J, Rey MD, Md Hatta MA, Hinchliffe A, Steed A, Reynolds D, et al (2018) Speed breeding is a powerful tool to accelerate crop research and breeding. Nature Plants 4, 23–29.
Speed breeding is a powerful tool to accelerate crop research and breeding.Crossref | GoogleScholarGoogle Scholar |

Whan BR, Rathjen AJ, Knight R (1981) The relation between wheat lines derived from the F2, F3, F4 and F5 generations for grain yield and harvest index. Euphytica 30, 419–430.
The relation between wheat lines derived from the F2, F3, F4 and F5 generations for grain yield and harvest index.Crossref | GoogleScholarGoogle Scholar |

Whan BR, Knight R, Rathjen AJ (1982) Response to selection for grain yield and harvest index in F2, F3, and F4 derived lines of two wheat crosses. Euphytica 31, 139–150.
Response to selection for grain yield and harvest index in F2, F3, and F4 derived lines of two wheat crosses.Crossref | GoogleScholarGoogle Scholar |

Yang R-C (2009) When is early generation effective in self-pollinated crops? Crop Science 49, 2065–2079.
When is early generation effective in self-pollinated crops?Crossref | GoogleScholarGoogle Scholar |

Yonezawa K (1983) Practical implications of improving the precision of genotype assessment in selection – a theory. Euphytica 32, 543–555.
Practical implications of improving the precision of genotype assessment in selection – a theory.Crossref | GoogleScholarGoogle Scholar |

Zheng TC, Zhang XK, Yin GH, Wang LN, Han YL, Chen L, Huang F, Tang JW, Xia XC, He ZH (2011) Genetic gains in grain yield, net photosynthesis and stomatal conductance achieved in Henan Province of China between 1981 and 2008. Field Crops Research 122, 225–233.
Genetic gains in grain yield, net photosynthesis and stomatal conductance achieved in Henan Province of China between 1981 and 2008.Crossref | GoogleScholarGoogle Scholar |