A modern tool for classical plant growth analysis.

We present an all-inclusive software tool for dealing with the essential core of mathematical and statistical calculations in plant growth analysis. The tool calculates up to six of the most fundamental growth parameters according to a purely 'classical' approach across one harvest-interval. All of the estimates carry standard errors and 95 % confidence limits. The tool is written in Microsoft Excel 2000 and is available free of charge for use in teaching and research from www.aob.oupjournals.org article supplementary data.

Cellular basis of the effects of gibberellin and the pro gene on stem growth in tomato.

Tomato (Lycopersicon esculentum Mill.) plants homozygous for the mutant pro gene, exhibiting the distinctive procera phenotype, appeared virtually identical to gibberellic acid (GA3)-treated isogenic normal plants. The pro gene and GA3 caused analogous increases in internode length, and in the length and number of cells in the outer cell layers of each internode. Internode number was also increased by pro and GA3 over the period of the experiment. Despite their greater length, the internodes of GA3-treated and pro plants reached their final size within a time period similar to that of internodes of untreated normal plants. The pro mutant itself was responsive to GA3, especially in the seedling stage, but the proportional increase in height seen in the later stages of growth was less than that of normal plants.

Changes in percentage organic carbon content during ontogeny.

Changes in percentage organic carbon content were assessed during the first five weeks of growth of Uniculm barley (Hordeum vulgare) and Brussels sprouts (Brassica oleracea) plants grown in controlled-environment conditions at two constant temperatures, 16° and 22°C. Foliage (leaf laminae), stem, and root material was assayed in both species, together with leaf sheaths of barley and cotyledon laminae of Brussels sprouts. In barley, there was a decline in percentage organic carbon content with increasing foliage age in plants grown at 22°C, but in sheath material there was no significant change at either temperature. Root material showed a decline in percentage carbon content at both growth temperatures, whereas stems showed the opposite trend. Similar results were found in Brussels sprouts, with an overall decline in percentage carbon content in foliage at 22°C and a rise in stem material at both growth temperatures. However, roots showed no significant change in percentage carbon content over the experimental period. The results demonstrate that percentage organic carbon content may change during plant growth.