Seed Size and Number in Rubus Chamaemorus: Between-Habitat Variation, and Effects of Defoliation and Supplemental Pollination
- 1 December 1989
- journal article
- research article
- Published by JSTOR in Journal of Ecology
- Vol. 77 (4) , 1080-1092
- https://doi.org/10.2307/2260824
Abstract
The within- and between-population variation in seed size and number were studied in eight populations of Rubus chaemaemorus in norhtern Sweden and Finland. Seed mass varied fourfold overall, up to threefold within populations, and up to twofold within single fruits. Ramets in shaded populations were larger, and produced larger seeds than ramets in open populations, but had a lower total seed-to-leaf mass ratio. Seed number and total seed mass per fruit did not differ consistently between open and shaded populations. Mean seed mass was negatively correlated with seed number per fruit, and with number of seeds per unit leaf and rhizome mass, respectively. Fruits that matured early contained more seeds and had a higher total seed mass than fruits that matured late. No change in mean seed mass was noted with time of fruit maturation. Mean seed mass did not vary as strongly between years as did seed number and total seed mass per fruit. Supplemental hand pollination in a shaded population increased seed number and total seed mass per fruit, but did not influence mean seed mass. Experimental defoliation did not influence fruit or seed set, nor total seed mass per fruit. Complete defoliation reduced mean seed mass by 13%. The production of larger seeds in the shade may reflect a variation between habitats in the optimal balance between seed number and size. However, it remains to be shown to what extent the between-habitat variation in seed and rhizome size is a result of phenotypic plasticity and genetic differentiation, respectively.This publication has 34 references indexed in Scilit:
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