[Show abstract][Hide abstract] ABSTRACT: Plantenveredeling staat tegenwoordig heel ver van de teler af. De reden is dat de moleculaire en genetische kennis enorme sprongen heeft gemaakt. Er is bovendien een hele geheimtaal ontstaan, waardoor de veredelaar vooral goed kan praten met vakgenoten en veel minder met de teler. Hier een aantal recente inzichten op een rij.
[Show abstract][Hide abstract] ABSTRACT: To improve our understanding of fruit growth responses to temperature, it is important to analyze temperature effects on underlying fruit cellular processes. This study aimed at analyzing the response of tomato (Solanum lycopersicum) fruit size to heating as affected by changes in cell number and cell expansion in different directions. Individual trusses were enclosed into cuvettes and heating was applied either only during the first 7 days after anthesis (DAA), from 7 DAA until fruit maturity (breaker stage), or both. Fruit size and histological characteristics in the pericarp were measured. Heating fruit shortened fruit growth period and reduced final fruit size. Reduction in final fruit size of early-heated fruit was mainly associated with reduction in final pericarp cell volume. Early heating increased the number of cell layers in the pericarp but did not affect the total number of pericarp cells. These results indicate that in the tomato pericarp, periclinal cell divisions respond differently to temperature than anticlinal or randomly oriented cell divisions. Late heating only decreased pericarp thickness significantly. Continuously heating fruit reduced anticlinal cell expansion (direction perpendicular to fruit skin) more than periclinal cell expansion (direction parallel to fruit skin). This study emphasizes the need to measure cell expansion in more than one dimension in histological studies of fruit
No preview · Article · Sep 2012 · Journal of the American Society for Horticultural Science. American Society for Horticultural Science
[Show abstract][Hide abstract] ABSTRACT: Understanding the molecular mechanisms and cellular dynamics that cause variation in fruit size is critical for the control of fruit growth. The aim of this study was to investigate how both genotypic factors and carbohydrate limitation cause variation in fruit size. We grew a parental line (Solanum lycopersicum L.) and two inbred lines from Solanum chmielewskii (C.M.Rick et al.; D.M.Spooner et al.) producing small or large fruits under three fruit loads (FL): continuously two fruits/truss (2&2F) or five fruits/truss (5&5F) and a switch from five to two fruits/truss (5&2F) 7 days after anthesis (DAA). Final fruit size, sugar content and cell phenotypes were measured. The expression of major cell cycle genes 7 DAA was investigated using quantitative PCR. The 5&5F treatment resulted in significantly smaller fruits than the 5&2F and 2&2F treatments. In the 5&5F treatment, cell number and cell volume contributed equally to the genotypic variation in final fruit size. In the 5&2F and 2&2F treatment, cell number contributed twice as much to the genotypic variation in final fruit size than cell volume did. FL treatments resulted in only subtle variations in gene expression. Genotypic differences were detected in transcript levels of CycD3 (cyclin) and CDKB1 (cyclin-dependent-kinase), but not CycB2. Genotypic variation in fruit FW, pericarp volume and cell volume was linked to pericarp glucose and fructose content (R2 = 0.41, R2 = 0.48, R2 = 0.11 respectively). Genotypic variation in cell number was positively correlated with pericarp fructose content (R2 = 0.28). These results emphasise the role of sugar content and of the timing of assimilate supply in the variation of cell and fruit phenotypes
No preview · Article · Jan 2012 · Functional Plant Biology
[Show abstract][Hide abstract] ABSTRACT: Wereldwijd nemen genetisch veranderde gewassen (GMO) een areaal in dat groter is dan het hele Europese landbouwareaal. Voor de glastuinbouw zijn GMO-gewassen momenteel nog van geringe betekenis, maar er zijn wel ontwikkelingen. Genetische modificatie is het gericht inbrengen van een gewenst gen. Dat vergt opsporen van het goede gen, isolatie en vervolgens inbrengen bij het cultuurgewas. Ingewikkelde processen die heel veel geld kosten. Ook als de maatschappelijke weerstand afneemt, blijft de 'gewone' veredeling erg belangrijk
[Show abstract][Hide abstract] ABSTRACT: The recently developed virtual plant modelling approach has strongly increased the potential of model applications in crop sciences. Virtual plants are based on a new modelling concept and are generated in a 3-dimensional (3D) virtual space. The technique facilitates the incorporation of 3D environmental effects on plant growth and development. The methodology to generate virtual plants is described for Arabidopsis flower mutants and for Chrysanthemum plants. The profiling method was used to create 3D images of existing plants by merging 2D digital pictures of the plant silhouette to a 3D object. The data from the digitised plants were used to calibrate an architectural model for Arabidopsis, based on the L-systems algorithm. This architectural model was able to simulate the morphological differences between a number of plant genotypes. On the basis of L-systems, a prototype architectural model was made for Chrysanthemum. The L-system calculated temperature driven growth and light interception on the basis of radiosity. A method is presented to link this 3D model to a physiological growth model to incorporate effects of carbon dynamics. The first results show that the combined strength of both models may help to understand and visualise plant growth and appearance.
No preview · Article · Aug 2004 · Acta horticulturae