The Concept of r- and K-Selection: Evidence from Wild Flowers and Some Theoretical Considerations

Gadgil, Madhav; Solbrig, Otto T.

doi:10.1086/282748

Cited by 569 publications

(271 citation statements)

References 9 publications

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“…This theory posits that that ability to allocate ones resources differentially in response to environmental condition is an adaptation allowing individuals to track and respond to environmental conditions, which will express itself phenotypically as individual within-species variation. Indeed, in a review of key life-history traits Rushton has shown that this sort of within-species variation does exist in diverse species such as; dandelions (Gadgil & Solbrig, 1972), field mice (Krebs, Gaines, Keller, Myers, & Tamarin, 1973), American shad (Leggett & Carscadden, 1978), as well as flies and milkweed bugs (Taylor & Condra, 1980).…”

Section: General Intelligence ('G') As a Latent Constructmentioning

confidence: 99%

A Life-History Model of Human Fitness Indicators

Sefcek

Figueredo

2010

Biodemography and Social Biology

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Section: General Intelligence ('G') As a Latent Constructmentioning

confidence: 99%

A Life-History Model of Human Fitness Indicators

Sefcek

Figueredo

2010

Biodemography and Social Biology

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“…Segundo Gadgil & Solbrig (1972) os conceitos de estrategista r e K não são absolutos e, sim, relativos. Pode-se comparar espécies sendo, entretanto, observadas variações dentro da mesma espécie, em conseqüência de diferentes genótipos.…”

Section: Resultados E Discussão Distribuição Fracionária De Energiaunclassified

“…Pode-se comparar espécies sendo, entretanto, observadas variações dentro da mesma espécie, em conseqüência de diferentes genótipos (Gadgil & Solbrig, 1972). Evenson (1983) afirmou que o método mais direto de determinação da alocação de energia dos tecidos de plantas se dá através da bomba calorimétrica.…”

Section: Introductionunclassified

Estratégias adaptativas de populações de Stylosanthes scabra provenientes de três regiões ecogeográficas de Pernambuco

Queiroz

Marcon

Filho

et al. 2001

Rev. bras. eng. agríc. ambient.

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Abstract Abstract Abstract: This research aimed to evaluate the genetic variability of 15 Stylosanthes scabra populations (Alfafa do Nordeste) as a result of the adaptation strategy to different environments from the regions: Mata, Agreste and Sertão in the state of Pernambuco. These populations, obtained from representative samples of seeds, were planted in a field trial at Campo Experimental da Empresa Pernambucana de Pesquisa Agropecuária (IPA). This trial served as a base for the study of fractional energy distribution. The energy allocation to the plant parts, described as a dry matter weight function, classified the populations as r and K strategists, evaluated during the 1 st reproductive cycle. The obtained results show that there is a great interpopulational variability for all the evaluated characters. Based on the obtained data, Brejos de altitude target Stylosanthes scabra populations for K strategists. The populations from Sertão behaved as r strategists. Populations with greater reproductive precocity, like that of Itamaracá, Serra Talhada and Santa Cruz da Baixa Verde, were classified as r strategists, directing a higher percentage of energy relative to the reproductive effort. The great variability between populations represents an adaptation strategy to the different environments as a process of genetic maximization in the species evolution.

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“…The negative relationship assumed to exist between perenniality and grain yield is largely based on life-history theory (e.g., Gadgil and Solbrig, 1972;Jackson and Jackson, 1999). Gardner (1989) has provided a physiological application of the theory to crop plants.…”

Section: B Resource Allocation and Negative Correlationsmentioning

confidence: 99%

Breeding Perennial Grain Crops

Cox

Bender

Picone

et al. 2002

BPTS

161

113

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Abstract:One-third of the planet's arable land has been lost to soil erosion in recent decades, and the pace of this degradation will increase as the limits of our food-production capacity are stretched. The persistent problem of worldwide soil erosion has rekindled interest in perennial grain crops. All of our current grain crops are annuals; therefore, developing an array of new perennial grains -grasses, legumes, and others -will require a long-term commitment. Fortunately, many perennial species can be hybridized with related annual crops, allowing us to incorporate genes of domestication much more quickly than did our ancestors who first selected the genes. Some grain crops -including rye, rice, and sorghum -can be hybridized with close perennial relatives to establish new gene pools. Others, such as wheat, oat, maize, soybean, and sunflower, must be hybridized with more distantly related perennial species and genera. Finally, some perennial species with relatively high grain yields -intermediate wheatgrass, wildrye, lymegrass, eastern gamagrass, Indian ricegrass, Illinois bundleflower, Maximilian sunflower, and probably others -are candidates for direct domestication without interspecific hybridization. To ensure diversity in the field and foster further genetic improvement, breeders will need to develop deep gene pools for each crop. Discussions of breeding strategies for perennial grains have concentrated on allocation of photosynthetic resources between seeds and vegetative structures. But perennials will likely be grown in more diverse agro-ecosystems and require arrays of traits very different from those usually addressed by breeders of annuals. The only way to address concerns about the feasibility of perennial grains is to carry out breeding programs with adequate resources on a sufficient time scale. A massive program for breeding perennial grains could be funded by diversion of a relatively small fraction of the world's agricultural research budget.

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The Concept of r- and K-Selection: Evidence from Wild Flowers and Some Theoretical Considerations

Cited by 569 publications

References 9 publications

A Life-History Model of Human Fitness Indicators

A Life-History Model of Human Fitness Indicators

Estratégias adaptativas de populações de Stylosanthes scabra provenientes de três regiões ecogeográficas de Pernambuco

Breeding Perennial Grain Crops

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