A complex dormancy mechanism in seeds of the weedRubus cuneifolius

Abstract

A complex dormancy mechanism in seeds of the weed Rubus cunei/o/ius J. van StadenDepartment of Botany, University of Natal Peta L. Campbell Plant Protection Research Institute, PietermaritzburgBoth the endocarp and embryo contribute to the dormancy of Rubus cuneifolius seed. Whereas scarification was found to break the dormancy imposed by the endocarp, embryo dormancy could only be overcome by a combination of treatments. These treatments consisted of a one·month stratification period followed by incubation at an alternating temperature of 10 -20 °C in the presence of light. S. Afr. J. Plant Soil 1984, 1: 48 -50Die endokarp sowel as die embrio dra by tot die rustoestand van Rubus cuneifolius·saad. Alhoewel skarifisering die rustoestand wat deur die endokarp veroorsaak word ophef, kon die rustoe· stand van die embrio slegs deur 'n kombinasie van behandelings opgehef word. Hierdie behandelings behels 'n stratifikasie·tydperk van een maand, gevolg deur inkubasie by wisselende temperature van 10 -20°C in die teenwoordigheid van lig. S.·Afr. Tydskr. Plant Grand 1984, 1: 48 -50

Improving weed management by targeting the seed ecology of blackberry (

“…Second, cutting the endocarp was found to promote germination, consistent with van Staden and Campbell (1984) who found that germination in R. cuneifolius could be achieved as long as the endocarp was scarified through cutting, or acid treatment. In contrast, acid treatment of the endocarp did not improve germination in R. anglocandicans, which was consistent with previous studies in a number of blackberry species (Wada and Reed 2011b;Choi et al 2016).…”

“…Choi et al (2016) found that for R. parvifolius, R. phoenicolasius, and R. takesimensis scarification (with sulphuric acid) needed to be combined with cold stratification (8 weeks at 4°C) to improve germination, owing to physiological dormancy reported in these species (Bewley et al 2013), whereas other species such as R. buergeri and R. corchorifolius did not respond to any imposed treatments. In contrast, van Staden and Campbell (1984) found that the most effective treatment of R. cuneifolius was immersion in concentrated sulfuric acid for 1.5 h. In R. anglocandicans, the physical suppression of germination still held despite acid treatments and germination occurred only once the endocarp was removed or damaged. Such variability in germination requirements reinforces the findings of previous studies that there are few generalisations to make for germination requirements among Rubus species.…”

“…S1). Similarly, in R. cuneifolius, an invasive species in subtropical South Africa, imbibition to 15% in fresh-mass increase is completed within 40 min (van Staden and Campbell 1984), demonstrating the rapid nature of moisture uptake into the pyrene.…”

“…Whereas previous studies have demonstrated improved germination after stratifying seeds at 5°C in subtropical Rubus species (e.g. van Staden and Campbell 1984), additional studies into whether cold stratification reduces time for after-ripening might be useful in understanding further germination cues for R. anglocandicans. Further studies could also investigate dry-wet cycles that mimic the field environmental clues that have an influence on dormancy loss (Hoyle et al 2008).…”