Plant Ideotype: The Concept and Application

The plant type concept in crop improvement started to receive major attention with the discovery of dwarfing genes in wheat and rice. The discovery and the analysis that followed showed that yield increases in many crops with the advent of scientific plant breeding are associated with better partitioning efficiency of the total dry matter produced, which on its own may have registered little increase. The two physiological parameters of crop yields — dry matter production and harvest index are now explicitly recognized as targets for future studies as major foodgrains of the world begin to reach a saturation point in their yields. The present paper describes the evolution of the plant type concept and discusses its wider implications. The concept is particularly relevant for modernization of traditional agriculture where genetic diversity for plant types could help to develop improved crop varieties responsive to applications of fertilizers, irrigation and other farm inputs. The plant type genes could help to accelerate the process of crop improvement in many of the developing countries.

[1]  W. R. Stern,et al.  Variation in skikelet initiation and ear development of old and modern Australian wheat varieties , 1989 .

[2]  M. Perry,et al.  Yield improvement and associated characteristics of some Australian spring wheat cultivars introduced between 1860 and 1982 , 1989 .

[3]  R. Sears,et al.  Genetic Improvement in Agronomic Traits of Hard Red Winter Wheat Cultivars 1919 to 1987 , 1988 .

[4]  S. Yoshida.  Fundamentals of rice crop science , 1981 .

[5]  D. Tennant,et al.  Root length density and water uptake in cereals and grain legumes: how well are they correlated , 1987 .

[6]  R. B. Austin,et al.  Genetic improvements in winter wheat yields since 1900 and associated physiological changes , 1980, The Journal of Agricultural Science.

[7]  R. Richards,et al.  Yield, Water Relations, Gas Exchange, and Surface Reflectances of Near‐Isogenic Wheat Lines Differing in Glaucousness1 , 1983 .

[8]  G. Slafer,et al.  Genetic-improvement effects on pre-anthesis physiological attributes related to wheat grain-yield , 1990 .

[9]  C. Donald,et al.  The Biological Yield and Harvest Index of Cereals as Agronomic and Plant Breeding Criteria , 1976 .

[10]  J. Mock,et al.  Changes in Physiological Traits Associated With Grain Yield Improvement in Three Maize Breeding Programs 1 , 1981 .

[11]  R. B. Austin,et al.  Effects of awns on the photosynthesis and yield of wheat, Triticum aestivum , 1976 .

[12]  R. B. Austin,et al.  Genetic improvement in the yield of winter wheat: a further evaluation , 1989, The Journal of Agricultural Science.

[13]  L. Evans,et al.  The contribution of stem reserves to grain development in a range of wheat cultivars of different height , 1971 .

[14]  S. Akita.  Improving yield potential in tropical rice. , 1989 .

[15]  N. Thompson,et al.  Review and evaluation , 1996 .

[16]  R. Belford,et al.  Root and Shoot Growth, and Water and Light Use Efficiency of Barley and Wheat Crops Grown on a Shallow Duplex Soil in a Mediterranean-type Environment , 1992 .

[17]  Neil C. Turner,et al.  Crop Water Deficits: A Decade of Progress , 1986 .

[18]  Richard Shibles,et al.  Varietal Differences in Net Photosynthesis of Soybean Leaves1 , 1970 .

[19]  B. G. Gengenbach,et al.  Breeding for Physiological Traits , 1983 .

[20]  D. Baldocchi,et al.  Leaf Pubescence Effects on the Mass and Energy Exchange Between Soybean Canopies and the Atmosphere1 , 1983 .

[21]  L. A. Hunt,et al.  Leaf Gas Exchange and Plant Growth of Winter Rye, Triticale, and Wheat under Contrasting Temperature Regimes , 1989 .

[22]  L. Schrader,et al.  Exploitation of physiological and genetic variability to enhance crop productivity , 1985 .

[23]  J. Bingham,et al.  Effect of awns and drought on the supply of photosynthate and its distribution within wheat ears , 1972 .

[24]  S. Tsunoda,et al.  Evolutionary trends in leaf photosynthesis and related leaf characters among cultivated wheat species and its wild relatives. , 1970 .

[25]  Peter J. Gregory,et al.  Effects of fertilizer on root growth and water use of barley in northern Syria , 1984, The Journal of Agricultural Science.

[26]  K. Siddique,et al.  Morphological and physiological traits associated with wheat yield increases in Mediterranean environments , 1994 .

[27]  Analysis on Difference of Dry Matter Production between Rice Cultivars with Different Plant Height in Relation to Gas Diffusion inside Stands , 1989 .

[28]  R. Richards,et al.  A Breeding Program to Reduce the Diameter of the Major Xylem Vessel in the Seminal Roots of Wheat and its Effect on Grain Yield in Rain-fed Environments , 1989 .

[29]  L. T. Evans.  The Natural History of Crop Yield , 1980 .

[30]  A. Makino,et al.  Photosynthesis and Ribulose 1,5-Bisphosphate Carboxylase in Rice Leaves: Changes in Photosynthesis and Enzymes Involved in Carbon Assimilation from Leaf Development through Senescence. , 1983, Plant physiology.

[31]  R. Belford,et al.  Growth, development and light interception of old and modern wheat cultivars in a Mediterranean-type environment , 1989 .

[32]  E. Heyne.  WHEAT AND WHEAT IMPROVEMENT , 1987 .

[33]  G. Slafer,et al.  Physiological attributes related to the generation of grain yield in bread wheat cultivars released at different eras , 1993 .

[34]  K. Siddique,et al.  Ear: Stem ratio in old and modern wheat varieties; relationship with improvement in number of grains per ear and yield , 1989 .

[35]  H. K. Jain.  Breeding for Yield and Other Attributes in Grain Legumes , 1975 .

[36]  I. M. Atkins,et al.  The Influence of Awns on Yield and Certain Morphological Characters of Wheat1 , 1955 .

[37]  E. Kirby,et al.  Convergence and synchrony-a review of the coordination of development in wheat , 1991 .

[38]  H. K. Jain,et al.  Dwarfing genes and breeding for yield in bread wheat , 1976 .

[39]  C. Donald.  The breeding of crop ideotypes , 1968, Euphytica.

[40]  J. Ozbun,et al.  Physiological Genetics of Crop Yield , 1972 .

[41]  R. B. Austin,et al.  The Fate of the Dry Matter, Carbohydrates and 14C Lost from the Leaves and Stems of Wheat during Grain Filling , 1977 .

[42]  R. Fischer,et al.  Changes in leaf photosynthesis with plant ontogeny and relationships with yield per ear in wheat cultivars and 120 progeny , 1983 .

[43]  F. Lupton.  Wheat Breeding: Its scientific basis , 1987 .

[44]  Gustavo A. Slafer,et al.  Genetic improvement of bread wheat (Triticum aestivum L.) in Argentina: relationships between nitrogen and dry matter , 1990, Euphytica.

[45]  L. T. Evans.  Crop evolution, adaptation, and yield , 1993 .

[46]  K. Howse,et al.  Root and shoot growth of semi‐dwarf and taller winter wheats , 1974 .

[47]  S. Simmons.  Growth, development, and physiology , 1987 .

[48]  K. Boote,et al.  Physiological Aspects of Peanut Yield Improvement 1 , 1978 .

[49]  J. Morgan,et al.  Leaf Gas Exchange and Related Leaf Traits among 15 Winter Wheat Genotypes , 1991 .

[50]  R. Summerfield.  World crops: Cool season food legumes , 1988, Current Plant Science and Biotechnology in Agriculture.

[51]  L. T. Evans,et al.  PHOTOSYNTHESIS, CARBON PARTITIONING, AND YIELD , 1981 .

[52]  H. Rawson,et al.  Fixation of 14Co2 by Flowering and Non-Flowering Glumes of the Wheat Ear, and the Pattern of Transport of Label to Individual Grains , 1972 .

[53]  P. Peltonen-Sainio.  Genetic Improvements in the Structure of Oat Stands in Northern Growing Conditions during this Century , 1990 .

[54]  R. A. Fischer,et al.  Number of kernels in wheat crops and the influence of solar radiation and temperature , 1985, The Journal of Agricultural Science.

[55]  D. H. Bell,et al.  Chapter 1 – Photosynthesis, Plant Productivity, and Crop Yield , 1980 .

[56]  K. Siddique,et al.  Grain growth and development of old and modern Australian wheats , 1989 .

[57]  K. Siddique,et al.  Contribution of stem dry matter to grain yield in wheat cultivars , 1991 .

[58]  R. B. Austin,et al.  Flag Leaf Photosynthesis of Triticum aestivum and Related Diploid and Tetraploid Species , 1982 .

[59]  H. Cao,et al.  Breeding for yield and quality in winter wheat consequences for nitrogen uptake and partitioning efficiency , 1985 .

[60]  Donald C. Rasmusson,et al.  An Evaluation of Ideotype Breeding 1 , 1987 .

[61]  L. T. Evans,et al.  Some physiological aspects of evolution in wheat. , 1970 .

[62]  J. Palta,et al.  Rate of Development of Postanthesis Water Deficits and Grain Filling of Spring Wheat , 1992 .

[63]  R. Fischer,et al.  Contribution of stored pre-anthesis assimilate to grain yield in wheat and barley , 1977, Nature.