Agriculture Reference
In-Depth Information
according to their experience, they identifi ed the varieties as winter va-
rieties (although the gene bank identifi ed them as spring varieties). MC
cultivated the varieties under plastic tunnels and in one-meter-wide beds
covered with plastic mulch, FD and AVO cultivated the varieties outside
and without plastic mulch.
The common trial of the third year was cultivated in spring, outside
in beds with plastic mulch. It was a split-plot design with three repli-
cates. Sub-blocks were composed of 32-plant plots of the different ver-
sions of one population variety, i.e., population N from the gene bank
and population(s) N + 2 from farmer(s). We added in this common trial
a commercial F1 hybrid variety (variety 'Lazio', Voltz seeds) in order to
compare levels of intra-varietal variability with the population varieties.
Phenotypic traits were observed on 15 plants per replicate for each version
of each variety.
Measurements were made on one well-developed and representative
leaf of each plant (at the harvestable stage). The traits measured are traits
used in the DUS evaluation, however, for DUS tests, traits are assessed
at the variety level, considering that the plants are homogeneous. Homo-
geneity (uniformity) is evaluated at a global level by the number of “off-
types” (plant which clearly do not look the same than others). Stability is
evaluated by comparison of different seed lots of the variety (year N and
year N − 5 for example) and distinctness is validated by visual comparison
with other varieties and by comparison with the breeder's description of
different traits. In our study, we observed development traits at plot level
(bolting and fl owering indexes) and the other phenotypic traits at the plant
level. The traits observed are presented in Table 4.
12.2.2 DATA ANALYSIS
Each variety was analysed separately. ANOVA tests were performed for
quantitative traits Y (i.e., petiole length, leaf blade length and width and
leaf color parameters), according to the model: Y ijk = μ + replicate i + ver-
sion j + ε ijk where “version” effect refers to original/farmer versions of
a variety. Chi square tests of the version effect were performed on the
distributions of the semi-quantitative traits (i.e., anthocyanin, petiole and
 
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