Summary
Under favorable nutrition, accessions of the weedy barleygrass (Hordeum leporinum and H. glaucum) had a higher relative growth rate (RGR) than did accessions of cultivated barley (H. vulgare) or its wild progenitor (H. spontaneum). RGR was not positively correlated with the presumed level of soil fertility at the collection site of an accession either within or among species. RGR was reduced more strongly by low-P supply in the progenitor than in the crop or weed, indicating that selection of cultivars to grow in fertile soils had not reduced their potential to grow effectively under low-P conditions. Seed and embryo masses were more important than RGR in determining plant size. Relative differences among assessions in plant size declined with time, because (1) accessions with small seeds had a higher RGR, and (2) RGR of large-seeded accessions declined with time. Absolute growth rate correlated positively with leaf area and negatively with photosynthetic rate per unit leaf area. Under favorable nutrition, maximum photosynthetic rate correlated negatively with leaf length and therefore was higher in the weeds than in the crop or progenitor accessions. P absorption potential did not differ consistently among species but generally increased in response to P stress. Cultivars produced a few tall tillers, whereas weeds and progenitors produced many small tillers. The cultivar had a larger proportion of reproductive tillers, allocated a larger proportion of biomass to grain, and produced larger grains than did the weedy accession. By contrast, the weed began maturing seeds sooner, produced more reproductive tillers, and produced more grains per car and per plant than did the cultivar. The study suggests two major conclusions: (1) A low RGR is not an adaptation to low P supply in annual Hordeum species. (2) Seed size is the major determinant of early plant size between accessions in these Hordeum species under favorable nutrition. However, large seed size indirectly results in a low RGR because of the inverse relationship between plant size and RGR and results in a low photosynthetic rate because of the inverse relationship between leaf size and photosynthesis.
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References
Barkworth ME, Dewey DR (1985) Genomically based genera in the perennial Triticeae of North America: identification and membership. Am J Bot 72:767–776
Bloom AJ (1985) Wild and cultivated barleys show similar affinities for mineral nitrogen. Oecologia (Berlin) 65:555–557
Booth TA, Richards AJ (1976) Studies in the Hordeum murinum aggregate. I. Morphology. Bot J Linn Soc 72:149–159
Brown AHD, Nevo E, Zohary D, Dagan O (1978) Genetic variation in natural populations of wild barley (Hordeum spontaneum). Genetica (The Hague) 49:97–108
Brouwer R (1966) Root growth of grasses and cereals. In: Milthorpe FL, Ivins JD (eds) The growth of cereals and grasses. Butterworths, London, pp 153–166
Chapin FS III (1980) The mineral nutrition of wild plants. Annu Rev Ecol Syst 11:233–260
Chapin FS III, Bloom AJ (1976) Phosphate absorption: adaptation of tundra graminoids to a low temperature, low phosphorus environment. Oikos 27:111–121
Chapin FS III, Wardlaw IF (1988) Effect of phosphorus stress on the source-sink interactions between the flag leaf and developing grain of barley. J Exp Bot 39:165–177
Cocks PS, Boyce KG, Kloot PM (1976) The Hordeum murinum complex in Australia. Aust J Bot 24:651–662
Cook MG, Evans LT (1983) Some physiological aspects of the domestication and improvement of rice (Oryza spp.). Field Crops Res 6:219–238
Donald CM, Hamblin J (1984) The convergent evolution of annual seed crops in agriculture. Adv Agron 36:97–143
Duncan WG, Hesketh JD (1968) Net photosynthetic rates, relative growth rates and leaf numbers of 22 races of maize grown at eight temperatures. Crop Sci 8:670–674
Evans LT (1976) Physiological adaptation to performance as crop plants. Philos Trans R Soc Lond B Biol Sci 275:71–83
Evans LT (1984) Physiological aspects of varietal improvement. In: Gustafson JP (ed) Gene manipulation in plant improvement. Plenum, New York, pp 121–145
Evans LT, Bush MG (1985) Growth and development of channel millet (Echinochloa turneriana) in relation to its potential as a crop plant and compared with other Echinochloa millets, rice and wheat. Field Crops Res 12:295–317
Evans LT, Dunstone RL (1970) Some physiological aspects of evolution in wheat. Aust J Biol Sci 23:725–741
Fenner M (1983) Relationships between seed weight, ash content and seedling growth in twenty-four species of compositac. New Phytol 95:697–706
Fitzsimmons RW, Wrigley CW (1984) Australian barleys. 2nd edition. CSIRO Australia, Melbourne
Gifford RM, Evans LT (1981) Photosynthesis, carbon partitioning and yield. Annu Rev Plant Physiol 32:485–509
Grime JP (1977) Evidence for the existence of three primary strategies in plants and its relevance to ecological and evolutionary theory. Am Nat 111:1169–1194
Grime JP, Hunt R (1975) Relative growth rate: its range and adaptative significance in a local flora. J Ecol 63:393–422
Gross KL (1984) Effects of seed size and growth form on seedling establishment of six monocarpic perennial plants. J Ecol 72:369–387
Harlan JR, De Wet JMM, Price EG (1973) Comparative evolution of cereals. Evolution 27:311–325
Harper JL (1977) Population biology of plants. Academic Press, London
Harrison AF, Helliwell DR (1979) A bioassay for comparing phosphorus availability in soils. J Appl Ecol 16:497–505
Heide OM, Bush MG, Evans LT (1985) Interaction of photoperiod and gibberellin on growth and photosynthesis of high-latitude Poa pratensis. Physiol Plant 65:135–145
Hewitt EJ (1966) Sand and water culture methods used in the study of plant nutrition. Tech Commun No 22 (2nd Edition). Commonwealth Agric Bur, Farnham Royal
Hoagland DR, Broyer TC (1936) General nature of the process of salt accumulation by roots with description of experimental methods. Plant Physiol 11:471–507
Khan MA, Tsunoda S (1970) Growth analysis of cultivated wheat species and their wild relatives with special references to dry matter distribution among different plant organs and to leaf area expansion. Tohoku J Agric Res 21:47–59
Lee RB (1982) Selectivity and kinetics of ion uptake by barley plants following nutrient deficiency. Ann Bot 50:429–449
Lush WM, Wien HC (1980) The importance of seed size in early growth of wild and domesticated cowpeas. J Agric Sci 94:177–182
marshall DL (1986) Effects of seed size on seedling success in three species of Sesbania (Fabaceae). Am J Bot 73:457–464
McCree KJ (1970) An equation for the rate of respiration of white clover plants grown under controlled conditions. In: Prediction and measurement of photosynthetic productivity (Proc IBP/PP tech meeting, Trebon). Cent Agric Pub Document (PUDOC), Wageningen, pp 221–229
Moore DRJ, Cavers PB (1985) A comparison of seedling vigour in crop and weed biotypes of proso millet (Panicum miliaceum). Can J Bot 63:1659–1663
Nye PH, Tinker PB (1977) Solute movement in the soil-root system. Univ California Press, Berkeley
Parsons RF (1968) The significance of growth-rate comparisons for plant ecology. Am Nat 102:595–597
Rawson HM, Hindmarsh JH, Fisher RA, Stockman YM (1983) Changes in leaf photosynthesis with plant ontogeny and relationships with yield per ear in wheat cultivars and 120 progeny. Aust J Plant Physiol 10:503–514
Rossiter RC (1964) The effect of phosphate supply on the growth and botanical composition of annual type pasture. Aust J Agric Res 15:61–76
Sarukhan J, Martinez-Ramos M, Piñero D (1984) The analysis of demographic variability at the individual level and its population consequences. In: Dirzo R, Sarukhan J (eds) Perspectives on plant population ecology. Sinauer Associates, Sunderland, pp 83–106
Schulze E-D, Chapin FS III (1987) Plant specialization to environments of different resource availability. In: Schulze E-D, Zwölfer H (eds) Potentials and limitations in ecosystem analysis. Springer, Berlin Heidelberg New York, pp 120–148
Tilman D (1988) Plant strategies and the dynamics and structure of plant communities. Princeton Univ Press, Princeton
Twine JR, Williams CH (1971) The determination of phosphorus in Kjeldahl digests of plant material by automatic analysis. Commun Soil Sci Plant Anal 2:485–489
Williams CH, Twine JR (1967) Determination of nitrogen, sulphur, phosphorus, sodium, calcium, and magnesium in plant material by automatic analysis. CSIRO Australia Div Plant Industry Tech Paper 24
Wulff RD (1973) Intrapopulational variation in the germination of seeds in Hyptis suaveolens. Ecology 54:646–649
Wulff RD (1986) Seed size variation in Desmodium paniculatum II. Effects on seedling growth and physiological performance. J Ecol 74:99–114
Zimmerman JK, Weis M (1983) Fruit size variation and its effects on germination and seedling growth in Xanthium strumarium. Can J Bot 61:2309–2315
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Chapin, F.S., Groves, R.H. & Evans, L.T. Physiological determinants of growth rate in response to phosphorus supply in wild and cultivated Hordeum species. Oecologia 79, 96–105 (1989). https://doi.org/10.1007/BF00378245
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DOI: https://doi.org/10.1007/BF00378245