Mansouri L.M.

Seed Germination and Seedling Establishment of Cherimoya (Annona Cherimola Mill.) at different Temperatures

A. Kheloufi, L.M. Mansouri, H. Khettache

ABSTRACT. Cherimoya (Annona cherimola Mill.) has an exceptional flavor and aroma, which makes it a fruit with great potential. However, little is known about its propagation by seeds. According to the scientific literature, the germination of cherimoya seeds is affected much more by external conditions than by internal conditions. Germination of cherimoya variety ‘Concha Lisa’ were tested for germination at constant temperatures of 25, 30, 40°C, and at room temperature, varying from 20-25°C, coupled with total darkness. Seeds were sown in Petri dishes (0.8% agar water), for 25 days of incubation. The kinetics of germination was determined according to five closely related parameters, viz. final germination percentage (FGP), mean germination time (MGT), coefficient of velocity of germination (CVG), time to 50% germination (T50) and seedling length (SL). The temperature of 30°C was found optimally suitable with 70.8% FGP, 17.5 days MGT and 3.91 cm SL, while the room temperature of 20-25°C slightly improved germination with only 25% FGP. Furthermore, significant decrease in FGP and SL was observed at 25°C and 40°C of temperature in comparison to 30°C. The analysis also revealed that cherimoya seed germination, day 10-15 after seed sowing is suitable for final counts. An overview on the emergence of cherimoya seedlings, during a 12-week period in pots is presented.

Keywords: agriculture; Annonaceae; custard apple; exotic fruit; fruit tree; seed quality.

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Effect of Cold Stratification on Seed Germination of The Multipurpose Fruit Shrub, Ziziphus Lotus (L.) LAM. (Rhamnaceae)

A. Kheloufi, L.M. Mansouri, K. Laib

ABSTRACT. Shrubs and trees of the genus Ziziphus are a good example of naturally occurring multipurpose plant species with great potential in arid regions. This study was conducted to investigate the effect of cold stratification on seed germination and seedling growth of Ziziphus lotus (L.) Lam. Seeds were subjected to 0, 45, 90 and 120 days of cold stratification at 5°C. We also examined fruit, kernel and seed morphology. For each treatment period, four replicates of 50 seeds were incubated in plastic containers between two layers of moist sand at 15% and under greenhouse conditions for 15-day period. At the end of the experiment, the final germination percentage (FGP), shoot length and root length were assessed. The results clearly indicated that increasing duration of cold stratification improved seed germination. The most effective stratification period was 120 days where Z. lotus recorded 83% of FGP and 16.5 cm of total seedling length. Cold stratification treatments significantly increased shoot height, root length, as well as seedling total length. 120 days stratification treatment resulted in the highest shoot and root length (6.80 cm and 9.75 cm, respectively). An overview on the emergence of Z. lotus seedlings during a 15-day period was also illustrated.

Keywords: agriculture; arid region; buckthorn; Jujube; medicinal plants; seed quality.

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Effect of Nitrogen Fertilizer on Growth, Flowering, Fruiting and Nodulation of Three Varieties of Common Bean in The Arid Region of Aïn Naga (Biskra, Algeria)

L.M. Mansouri, A. Kheloufi, R. Belatreche, N. Heleili, Z.F. Boukhatem

ABSTRACT. Field experiments were conducted to investigate the response of common bean (Phaseolus vulgaris L.) to nitrogen fertilizer. The main factor included the fertilizer (Granular Urea 46% N), was made up of two levels: no fertilization (0 kg/plot: control) and fertilization (0.4 kg/plot), while the secondary factor was the variety (three varieties of common bean: Djedida, Nelson and Jalila). The experimental design was a randomized complete block design with split plot arrangement and replicated four times. The effect of fertilization was evaluated during two development stages (flowering and fruiting) for each variety and this on the total dry biomass, the length of the aerial and root parts, as well as on the number of secondary roots. On the other hand, the combined effect of fertilization and variety was studied on some yield parameters per plant, such as the number of flowers, pods, seeds and the harvest index. In addition, the number of nodules at the end of seed maturation was evaluated. The results indicated that the nitrogen fertilizer application significantly reduced the root length, the number of nodules and secondary roots in most of the common bean varieties. However, fertilizer application significantly increased dry matter in both flowering and fruiting stages, for the three studied varieties. Pod number per plant and seed yield was increased by the application of N fertilizer, depending on varieties and the parameters being measured. Djedida and Jalila varieties gave the best yield and can therefore be recommended to farmers. According to our results, the percentage of improvement by N fertilization on one parameter or another does not exceed an average of 20%, compared to the control. Indeed, the effect of fertilization is positive and seems to increase the harvest index by 18% in Djedida and by 20% in Jalila, compared to non-fertilized plants. Unfertilized plants of the variety Nelson showed the highest ability to nodulate.

Keywords: agriculture; dry matter; crops; Fabaceae; Phaseolus vulgaris; yield.

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Seed germination and radicle establishment related to type and level of salt in common bean (Phaseolus Vulgaris L. Var. Djedida)

L.M. Mansouri, N. Heleili, Z.F. Boukhatem, A. Kheloufi

ABSTRACT. Saline soils contain multiple types of salt, each of them may exert a different effect on seed germination and seedling growth. The aim of this study is to assess the effects of five types of salt on the seed germination and radicle establishment of common bean (Phaseolus vulgaris L. var. Djedida). The experiment was set out as a factorial experiment based on completely randomized design with four replications of ten seeds for the seed germination and twelve replicates for the seedling growth. We used five kinds of salts (NaCl, Na2SO4, CaCl2, CaCO3 and KCl) with concentrations of 0, 100, 200 and 300 mM. Seeds were incubated in Petri dishes at 25°C, in the dark, for 10 days. The results of analysis of variance indicated that the effects of salt types and concentrations, and their interaction effect were significant in all measured traits (P< 0.01). However, no significance effect was found on secondary roots number and seedlings dry biomass with CaCO3 treatment solution. According to the results, the inhibitory effects of the five salt types differed significantly. Indeed, germination of common bean seeds by various salts were in the order of NaCl > KCl > CaCO3 > Na2SO4 > CaCl2. However, the taproot length, the number of secondary roots and the seedlings dry weight by various salts were in the order of CaCO3 > KCl > NaCl > CaCl2 > Na2SO4. The effect of salt concentration was also obvious. The reduction in dry biomass of cotyledons is proportional to germination rates and to the development of seedlings in dry biomass and in size. Seeds of P. vulgaris var. Djedida were able to germinate under all concentrations of the various types of salt. The lowest final germination percentage (FGP) was obtained under 300 mM of all salts recording the following values: CaCO3 – 60%, NaCl – 60%, KCl – 52.5%, Na2SO4 – 50% and CaCl2 – 27.5%. During germination stage, the radicle emergence would be controlled by the environment osmolarity, while the later growth of the seedling would be limited by the reserve mobilization.

Keywords: agriculture; Fabaceae; local adaptation; osmotic stress; salt tolerance.

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Morphological characteristics and seed germination improvement of two ecotypes of Astragalus Armatus Willd. subsp. Armatus in Algeria

A. Kheloufi, L.M. Mansouri, B. Bouafia, Y. Khamari, H. Kheloufi, Y. Bouguern

ABSTRACT. Astragalus armatus Willd. subsp. armatus is an endemic shrub of the Northern Africa. Its cultivation and domestication are very limited because of difficulty with seed germination and establishment. In this study, we investiga-ted some plant morphological characteris-tics in real time and in situ (leaves, fruit and seeds) of different ecotypes of A. armatus, collected from two sites in Algeria (Arid Steppe of Aïn Naga and Condorcet Mountain), which elevation and climate data are very different. Moreover, the role played by the seed coat in seed dormancy of these two different populations was tested by the effects of the pretreatment and its duration on the performance of seed germination, by considering the final germination percentage (FGP) and the mean germina-tion time (MGT). These parameters are estimated for 10 days in Petri dishes and stored in darkness at (25°C). Pre-sowing treatments included immersion in concentrated sulphuric acid for 30, 60 and 90 min, and immersion in hot water (100°C) for 10 min. Statistical analysis showed that the treatment and the eco-types effects on both FGP and MGT were highly significant (p< 0.0001). Untreated seeds of both ecotypes of A. armatus failed to germinate (except for a few of Condorcet Mountain ecotypes). For both populations, the most effective treatment was immersion in sulphuric acid for 60 min for the ecotype of Arid Steppe of Aïn Naga, and only 30 min for Condorcet Mountain. An excellent germinative strength is characterized by a higher FGP and a reduced MGT. The morphological characteristic and seed germination could be attributed to intraspecific variations resulting from the natural selection of the same species. Keywords: Astragalus armatus; desert shrub; ecotype; germination; scarification.

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