Spatial heterogeneity in light supply is common in nature. Many studies have examined the effects of heterogeneous light supply on growth, morphology, physiology and biomass allocation of clonal plants, but few have tested those effects on intraspecific competition. In a greenhouse experiment, we grew one (no competition) or nine ramets (with intraspecific competition) of a stoloniferous clonal...

In the search for time- and tissue-specific promoters an RNA fingerprinting technique called cDNA-AFLP was used. A transcript derived fragment (TDF511) was isolated which showed high similarity to alcohol dehydrogenases. The gene corresponding to this TDF, named Stgan, is likely to be involved in biosynthesis or breakdown of compounds affecting gibberellic acid (GA) levels in the plant [Plant J...

Ethylene inhibited the tuberization of etiolated potato (Solanum tuberosum L. var. Red La Soda) sprout sections cultured in vitro. Carbon dioxide did not overcome the C(2)H(4) inhibition but it was required for normal tuberization. Ethylene totally prevented root formation and development. It inhibited stolon elongation, and caused thickening and diageotropical growth of the stolon. In addition...

Many notorious invasive plants are clonal, living in heterogeneous or homogeneous habitats. To understand how clonal integration affects the performance of these plants in different habitat conditions, an 8-week greenhouse experiment was conducted: ramet pairs of A. philoxeroides were grown in two habitats, either heterogeneous or homogeneous in water availability, with the stolon connections e...

The intensity of "tuberization stimulus" in potato shoots (Solanum tuberosum L.) can be assessed from cuttings containing one or more leaves. Cuttings maintained in a mist chamber under long days will form tubers from underground buds if prior to taking the cutting the leaves received sufficient exposure to photoperiods less than the critical photoperiod. The greatest tendency to tuberize was f...

The ability to propagate via small diaspores is crucial for the invasion of a clone plant that does not reproduce sexually in its introduced range. We investigated the effects of node and internode adjacent mode, fragment type, burial orientation and position of the node in relation to the soil surface on the sprouting and growth of alligator weed (Alternanthera philoxeroides (Martius) Griseb.)...

A new rosulate species of Viola from the high Andes Neuquén in Argentina, V. marcelaferreyrae, is here described, illustrated, and categorized according to its conservation status. Additionally, we compare with morphologically geographically allied species, anitae escondidaensis, discuss preliminary placement sect. Rhizomandinium due presence stolon-like perennating axes. key section together i...