Revue internationale d'écologie méditerranéenne International ...

PHENOTYPIC AND PHENOLOGICAL BEHAVIOURS OF CLONES OF NATURAL POPULATIONS OF ATRIPLEX HALIMUS ◆
watered at the same rate for four months to aid in their
establishment, and then not watered at all. In one of these
parcels, clones have been irrigated in a continuous way at
a rate of once per week (5 liters / individual). Individuals
were monitored weekly to determine their phenological
stage. The beginning of every phenological stage was
noted when more than 70% of individuals presented
specific features (floral buds, flowering and fruiting).
In September of 2001 and 2002, five inflorescences of
each individual were harvested following the four cardinal
orientations. For each inflorescence, the length of inflorescence
(LI), the number of secondary ramifications in
every inflorescence (NR) and the number of male (MF)
and female (FF) flowers formed were determined. The
maximum height (H max), the maximum (CW max) and
minimum (CW min) crown diameter, the circumference
(Cir) and the number of inflorescences (IN) for each
individual Were also measured only during the first year
(2001). On November of the years (2001, 2002) fruits
were collected from each individuals. For every one, we
estimated the percent of fruits infested with insect (IR),
the percent of immature seed (IS) and dry weight of 100
seeds chosen randomly (SW).
The data were analysed using SPSS for Windows analysis
(SPSS, 1994). The multivariate analysis of variance
ecologia mediterranea, tome 29, fascicule 2, 2003, p. 179-188
was used (ANOVA). The main effects population (3),
year (2), treatment (2) and individuals (30) were treated
as a fixed factors. P < 0.05 was used to define statistical
significance. If a significant difference was determined
among means, a Student-Neuman-Keuls (SNK) test was
used to determine significant difference between pairwise
comparison between treatment. The percent data were
arcsine transformed before analysis to ensure homogeneity
of variance.
RESULTS
Phenological variability
Direct observations showed that individuals of the
three populations placed in the same climatic conditions
exhibited variable phenology. Floral buds formation, in
both irrigated and non-irrigated individuals was earlier
for the Idelssen population (mid June), and late for those
of Marrakech and Sidi Bouzid populations (end of June).
However, the bursting of these floral buds is earlier for
individuals of Sidi Bouzid and Marrakech populations.
These floral buds generally give rise to male flowers (protandrous
species). The female flowers appeared around
F
Source of variance df MF FF MF/FF LI NR
Population 2 668.70*** 254.76*** 688.91*** 580.32*** 176.85***
Year 1 0.235 0.000 1.27 0.000 0.04
Treatment 1 8382.7*** 6701.85*** 1267.4*** 7060.41*** 2332.56***
Individual 29 3.005*** 3.47*** 1.4 5.23*** 4.36***
Population by Year 2 0.044 0.001 1.445 0.000 11.96***
Population by treatment. 2 934.51*** 690.92*** 708.94*** 178.07*** 50.96***
Population by Individual 1 2.92*** 4.19*** 6.706*** 5.19*** 3.187***
Year by treatment 58 0.555 0.001 1.665 0.000 0.502
Year by individual 29 0.612 0.000 0.513 0.000 0.802
Treatment by Individual . 29 3.103*** 3.068*** 1.999** 5.93*** 5.53***
Population by Year by treatment 2 0.434 0.000 7.105*** 0.000 0.933
Population by year by individual 58 0.546 0.001 0.606 0.000 0.830
Population by treatment by individual 58 3.268*** 4.803*** 6.968*** 4.979*** 2.743***
Year by treatment by individual 29 0.583 0.000 0.599 0.000 0.935
Population by year by treatment by individual. 58 0.636 0.001 0.712 0.000 0.843
** (P < 0.01); *** (P < 0.001).
Table 2. Analyse of variance of flowering parameters (number of male (MF) and female flowers (FF),
floral sex ratio (MF/FF), length of inflorescence (LI) and number of secondary ramification per inflorescence (NR)).
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