Seed Size Variation in Desmodium Paniculatum: I. Factors Affecting Seed Size

Abstract

JSTOR is a not-for-profit service that helps scholars, researchers, and students discover, use, and build upon a wide range of content in a trusted digital archive. We use information technology and tools to increase productivity and facilitate new forms of scholarship. For more information about JSTOR, please contact support@jstor.org. This content downloaded from 128.235.251.160 on Mon, SUMMARY(1) In a population of Desmodium paniculatum seed weight varies by a factor of about four. Increase in temperature during the growth of the plants, reduces nutrient and water availability, and shortening of the photoperiod decreases the mean seed weight. A 50% reduction (to mimic grazing loss) in total leaf area during seed development increases mean seed weight of plants grown at high temperatures.( 2) Seed size varies significantly among individual plants, but there is no correlation between mean seed weight per plant and total numbers of seeds produced per plant. Within a plant, seed size may vary by as much as a factor of two if grown under highnutrient supply, but this variability is significantly reduced if plants are grown with limited nutrients. Part of the within-plant variability is due to the production of fruits with a variable number of seeds and to the position of the seed within a fruit. Seedlings from different positions within the fruit have different probabilities of survival.(3) In plants grown with low (but not with high) nutrients, parental seed sizes are positively correlated with offspring seed sizes. Seed size may thus affect the subsequent generation.

Propagule size and predispersal damage by insects affect establishment and early growth of mangrove seedlings

“…Despite Harper et al's (1970) prediction that seed size should be a canalized trait that varies little within a species, intraspecific variation in seed size, of similar or greater magnitude to that which we observed, has been demonstrated in numerous subsequent studies. Such variation occurs over a wide range of spatial scales: within plants, among plants, and among populations (Wulff 1973(Wulff , 1986aSchaal 1980;Howe and Richter 1982;Stanton 1984;Winn 1988;Moegenburg 1996;Ramsey 1997, 1998;Eriksson 1999).…”

Parental environmental effects on life history traits in Arabidopsis thaliana (Brassicaceae)

“…Even small differences among the environments in which parental (or even grandparental) plants are raised can generate large phenotypic differences among their progeny with respect to both size and performance (Austin, 1966a,b ;Gutterman et al, 1975 ;Pet & Garretsen, 1983 ;Alexander & Wulff, 1985 ;Wulff & Alexander, 1985 ;Wulff, 1986 ;Miao et al, 1991 ;Schmitt et al, 1992 ;Wulff & Bazzaz, 1992 ;Curtis et al, 1994 ;Delesalle & Blum, 1994 ;Hume, 1994 ;Mazer & Gorchov, 1996). Because such maternal environmental effects can result in the transmission of phenotypic effects across generations independently of the genes expressed by the maternal nuclear genotype, maternal environmental effects may mask additive genetic variation.…”

Tamaño y viabilidad de semillas: implicancias en la evolución y conservación de Phaius tankervilleae (Orchidaceae)

“…Consecuentemente, el tamaño de la semilla se considera como un indicador de calidad fisiológica dado que se correlaciona positivamente con el vigor de las plantas (Aguiar 1995, Rendón et al 2002, Aráoz et al 2004, y mayor capacidad de sobrevivencia, por lo que el tamaño de la semilla puede afectar potencialmente no sólo el éxito inmediato de las plántulas, sino también la generación siguiente (Wulff 1986). …”