Schriften zu Genetischen Ressourcen - Genres

U. FREYTAG, G.H. BUCK-S ORLIN and B. SCHMIDT
Evaluation of pod, seed, and phenological traits of standard genebank
accessions of common bean (Phaseolus vulgaris L.) over a
period of eight years
U. FREYTAG 1 , G.H. BUCK-SORLIN 2 and B. SCHMIDT 1
Abstract
Six standard genebank accessions of common bean (Phaseolus vulgaris L.) were
cultivated over a period of eight years (1993-2000) within the frame of a long-term
field trial at the IPK in Gatersleben. Morphological and phenological traits were assessed
routinely in the field every year; additionally, typical pods and seeds of each
accession and year were documented as digital images and further traits automatically
measured using a digital image analysis system (DIAS). Using such a DIAS (the
software QWin in this case), it is possible to rapidly capture pod and seed features
that are normally difficult or impossible to measure otherwise (e.g., roundness of
shape, circumference). Analysis of Variance of all traits measured, carried out for the
factors genotype as well as temperature, precipitation, air humidity for the vegetation
months May to August of each year, yielded a very diverse picture: whereas, e.g., the
variation in most seed-related traits appeared to be due to the factor genotype (especially
Thousand-Grain-Weight), the variance observed in the duration of the vegetation
period or germination rate exhibited a complicated network of, sometimes contrasting,
microclimatic factors. The findings of this study are discussed in connection
with their consequences for the evaluation of trait data for taxonomic and genebank
work.
Introduction
The accurate characterisation of genebank accessions of a crop species under consideration
of all available morphological, phenological, and molecular information is
the basis of every sensible breeding programme. However, in carrying out such investigations,
the climate-related variability of certain traits relevant to breeding is un-
1
Institute of Plant Genetics and Crop Plant Research (IPK)
Dept. of Genebank
Corrensstr. 3
D-06466 Gatersleben, Germany
2
Institute of Plant Genetics and Crop Plant Research (IPK)
Dept. of Taxonomy
Corrensstr. 3
D-06466 Gatersleben, Germany
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