Presentation on theme: "Variation in cone and seed traits among provenances of Cedrus atlantica Manetti in Algeria. A. DERRIDJ and F. KROUCHI Laboratory of Forest biosystematics."— Presentation transcript:
Variation in cone and seed traits among provenances of Cedrus atlantica Manetti in Algeria. A. DERRIDJ and F. KROUCHI Laboratory of Forest biosystematics Faculty of Biological and Agronomic Sciences Mouloud Mammeri University (Tizi-Ouzou, Algeria).
Material and methods On cones collected in year 1986 we measured the following parameters: - Fresh weight of a random sample of 1000 seeds; - Fresh weight of 1000 filled seeds; - Amount of filled seeds; - Dry weight of 1000 filled seeds; - The moisture content of seeds. Cones were collected on 11 provenances distributed through two chains of mountains, with the following coordinates range: 35°17 to 36°30N in latitude ; 1°40E to 6°40 in longitude. Among these provenances one is artificial.
On cones collected in 1987 we measured the following parameters: - Seed length and diameter; - Weight of 1000 seeds; - Total number of seeds in 100 cones; - Number of filled seeds in 100 cones; - Amount of filled seeds; - Number of cones necessary to obtain 1000 filled seeds; - Number of filled seeds per a hectoliter of cones; - Weight of filled seeds per a hectoliter of cones. The data was submitted to graphical analyses and analysis of variance.
Results : Cone dimensions : The same group of provenances showed lower values of cone weight, length and diameter. Table1: Means values for cone dimensions among provenances.
Seed dimensions Fig.1: Distribution of seed diameter among provenances (cones collected in 1987).
seed length showed a better segregation between provenances than diameter. Seed dimensions Fig.2:Distribution of seed length among provenances (cones harvested in 1987 ).
In 1986 the amount of filled seeds per cone ranged between 84 and 98% and decreased in1987. Fig.3:Variation in amount of filled seeds between provenances over two consecutive years. Seed yield
In mast years, fresh weight of a random sample of seeds and of the proportion of filled seeds as well the dry weight of 1000 filled seeds are concordant. Seed weight Fig.4: Variation among provenances for seed weight measured in different ways (cones collected in1986).
Fig.5:Variation in weight of seeds in a hectoliter of cones. Fig.6:Variation in the number of filled seeds in a hectoliter of cones. Per provenance we can expect between 1.43 and 4.98 kg of filled seeds in a hectoliter of cones. we can expect between and of filled seeds in a hectoliter of cones.
Conclusion: Provenance rank for cone dimension is not concordant with their rank for seed yield: for example amount of filled seeds per cone is not correlated to cone dimensions. Any cedrus atlantica provenance, even artificial one, may provide a good amount of sound seeds in years of mast fruiting. These provenances may also provide seeds of good germinative capacities (data not shown). Thus,for nursery purposes and reforestation programs, one may collect seeds preferably in mast fruiting years from any provenance.