Summary
This study examines the pattern of reproduction and factors that limit the maternal reproductive output in the self-incompatible annual, Lesquerella gordonii. Greenhouse experiments showed that fruits do not abscise and they mature if they contain at least one fertilized (outcrossed) ovule. Field studies showed that flowering increased to a peak and then fell off rapidly, while seed production/fruit decreased through the season. Pollen addition did not increase the number of fruit or seeds per fruit, suggesting that fruit and seed production are not pollinator limited. Addition of water increased fruit and seed production by extending the life of the plant, by increasing the number of stalks which flowered, and by increasing the number of seeds per fruit. This indicates that fruit and seed production are resource limited. Fruits are relatively inexpensive as compared to seeds as over 93% of the water in fruits is contained in the seeds. Fifty-three percent of the plants were lost to herbivory as were 64.6% of the fruits on the remaining plants, indicating that herbivory also limited fruit and seed production. It is hypothesized that high fruit set coupled with variable seed set in L. gordonii is an adaptive response to unpredictable, variable resource levels, and high herbivory risk.
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References
Aker CL (1982) Regulation of flower, fruit and seed production by a monocarpic perennial, Yucca whipplei. J Ecol 70:357–372
Bazzaz FA, Carlson RW, Harper JL (1979) Contribution to reproductive effort by photosynthesis of flowers and fruit. Nature 279:554–555
Bawa KS, Webb CJ (1984) Flower, fruit and seed abortion in tropical forest trees: implications for the evolution of paternal and maternal reproductive patterns. Am J Bot 71:736–751
Bierzychudek P (1981) Pollinator limitation of plant reproductive effort. Am Nat 117:838–840
Brown JH, Davidson DW, Munger JC, Inouye RS (1985) Experimental community ecology: the desert granivore system. In: Diamond JM, Case TJ (eds) Community Ecology. Harper and Row, New York (in press)
Casper BB, Wiens D (1981) Fixed rates of random ovule abortion in Cryptantha flava (Boraginaceae) and its possible relation to seed dispersal. Ecology 62:866–869
Charnov EL, Bull JJ (1977) When is sex environmentally determined? Nature 266:828–830
Cohen D (1966) Optimizing reproduction in a randomly varying environment. J Theor Bio 12:119–129
Faegri K, Pijl L van der (1979) The Principles of Pollination Ecology. 3rd ed. Pergamon Press, Oxford
Gillespie JH (1977) Natural selection for variances in offspring numbers: a new evolutionary principle. Am Nat 111:1010–1014
Handel SN, Mishkin JLV (1984) Temporal shifts in gene flow and seed set: evidence from an experimental population of Cucumis sativus. Evolution 38:1350–1357
Heinrich B, Raven PH (1972) Energetics and pollination ecology. Science 176:597–602
Hendrix SD (1984) Reactions of Heracleum lanatum to floral herbivory by Depressaria pastinacella. Ecology 65:191–197
Herrera CM (1981) Fruit variation and competition for dispersers in natural populations of Smilax aspera. Oikos 36:51–58
Heslop-Harrison J (1957) The experimental modification of sex expression in flowering plants. Biol Rev Camb Philos Soc 32:38–90
Janzen DH (1971a) Escape of Cassia grandis L beans from predators in time and space. Ecology 52:964–979
Janzen DH (1971b) Seed predation by animals. Ann Rev Ecol Syst 2:465–492
Janzen DH (1975) Intra- and interhabitat variation in Guazuma lemifolia (Sterculiaceae) seed predation by Amblycerus cistelinus (Bruchidae) in Costa Rica. Ecology 56:1009–1013
Janzen DH (1976) Two patterns of pre-dispersal seed predation by insects on Central American deciduous forest trees. In J Burley and BT Styles (eds) Tropical Trees: Variation, Breeding, and Conservation. Academic Press, London, pp 179–188
Janzen DH, DeVries P, Gladstone DE, Higgings ML, Lewishon MT (1980) Self-and cross-pollination of Eucyclia cordigera (Orchidaceae) in Santa Rosa National Park, Costa Rica. Biotropica 12:72–74
Lee TD, Bazzaz FA (1982a) Regulation of fruit and seed production in an annual legume, Cassia fasciculata. Ecology 63:1363–1373
Lee TD, Bazzaz FA (1982b) Regulation of fruit maturation pattern in an annual legume, Cassus fasciculata. Ecology 63:1374–1388
Lloyd DG (1980) Sexual strategies in plants. I. An hypothesis of serial adjustment of maternal investment during one reproductive session. New Phytol 86:69–79
Lloyd DG, Webb CJ, Primack RB (1980) Sexual strategies in plants. II. Data on the temporal regulation of maternal investment. New Phytol 86:81–92
McKey D (1975) The ecology of co-evolved seed dispersal. In: Gilbert LG, Raven PH (eds) Coevolution of Animals and Plants. University of Texas Press, Austin, pp 159–191
Mulroy TW, Rundel PW (1977) Annual plants: adaptations to desert environments. Bioscience 27:109–114
Primack RB (1978) Regulation of seed yield in Plantago. J Ecol 66:835–847
Real LA (1980) On uncertainty and the law of diminishing returns in evolution and behavior. In JER Staddon (ed)_ Limits to Action. Academic Press, New York, pp 37–64
Rollins RC, Shaw EA (1973) The Genus Lesquerella (Cruciferae) in North America. Harvard University Press, Cambridge
Schemske DW (1980) Evolution of floral display in the orchid Brasscvola nodosa. Evolution 34:489–493
Stearns SC (1976) Life-history tactics: a review of the ideas. Quart Rev of Bio 51:3–47
Stephenson AG (1979) An evolutionary examination of the floral display of Catalpa speciosa (Bignoniaceae). Evolution 33:1200–1209
Stephenson AG (1980) Fruit set, herbivory, fruit reduction, and the fruiting strategy of Catalpa speciosa (Bignoniaceae). Ecology 61:57–64
Stephenson AG (1981) Flower and fruit abortion: proximate causes and ultimate functions. Ann Rev Ecol Sys 12:253–279
Stephenson AG (1984) The regulation of maternal investment in an indeterminant flowering plant (Lotus corniculatus). Ecology 65:113–121
Sutherland S (1982) The pollination biology of paniculate agaves: documenting the importance of male fitness in plants. PhD Thesis, University of Arizona, Tucson
Willson MF (1979) Sexual selection in plants. Am Nat 113:777–790
Willson MF, Burley N (1983) Mate Choice in Plants: Mechanisms and Consequences. Princeton Biological Monographs, Princeton
Willson MF, Price PW (1977) The evolution of inflorescence size in Asclepias (Asclepiadaceae). Evolution 31:495–511
Willson MF, Rathcke BJ (1974) Adaptive design of the floral display in Asclepias syriaca L. Am Mid Nat 92:47–57
Yoshida S (1972) Physiological aspects of grain yield. Ann Rev Plant Physiol 23:437–464
Zimmerman M (1980) Reproduction in Polemonium: competition for pollinators. Ecology 61:497–501
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Delph, L.F. Factors regulating fruit and seed production in the desert annual Lesquerella gordonii . Oecologia 69, 471–476 (1986). https://doi.org/10.1007/BF00377071
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DOI: https://doi.org/10.1007/BF00377071