Auxin deficiency at the onset on root growth in Allium cepa
Summary3-Indolylacetic acid (IAA) increased the length of the epidermis cells of onion roots during the initial stage of root growth, when cell length has not yet reached its maximum value, by up to 50% (10−11 M), while in the later, steady-state or dynamic equilibrium stage no promotive effects were present. It is suggested that the lesser elongation capacity of the cells at the onset of root growth is related to a deficiency in auxin while the steady-state phase is characterized by hormonal balance.
Growth components in Allium roots
SummaryThis paper reports results of a study of root growth, duration of the division cycle, and cell size for different intervals of root length, associated with different phases of growth, namely, from the onset of growth to the achievement of a steady state characterized by a constant rate of growth. The material is roots of Allium cepa.Steady-state kinetics of growth are achieved only when all components of growth reach a constant value. Although the cell flow remains constant from a root length of 8 mm onwards, the steady condition is only observed when the final size of the epidermal cells reaches its maximum and constant value (at about 12 mm of root length).The equation G=24×10-5 \N\φ·L is proposed to analyze the growth of Allium roots in its components. G is the growth rate (mm/24 hr), N the number of cells per column in the meristematic ribs, φ the rate of the cell cycle (the reciprocal of its duration x100), and L the average final size of the epidermal cells (in μ).
Assessment of some agro-technological parameters of cactus pear fruit ( Opuntia ficus-indica Mill . ) in Morocco cultivars
Cactaceae had always attracted attention by their strange shapes and important adaptability supporting extreme conditions. For this reasons, Fruit traits were measured on 13 cultivars growing in different locations in Morocco. Results show significant differences between the cultivars. The source of this variation was probably genetic without excluding the geographic effects. The Tamri, Berkan, Ait Baha cultivars showed small fruit dimensions and weight. In contrast, Sidi-Ifni M, Nador, Mohammedia and Ben Guerir were greater than 100 g by fruit. Sidi-Ifni M, Hoceima, Mohammedia and Nador, although larger, contained few seeds, about 200 seeds per fruit; while Tamri, Ait Baha, Safi, Meknes and Tafraout contained over than 230 seeds per fruit. High levels of juice about 62 ml/100 g pulp were obtained with Sidi-Ifni M, Nador, Mohammedia and Ben Guerir cultivars. Total sugars of the 13 cultivars were quite similar and pH was low in Tamri and close to neutrality in the rest of cultivars. Therefore, oil extracted from Opuntia ficus-indica seeds constituted 13.6% of the whole seed. Thin-layer chromatography in conjunction with gas-liquid chromatography-mass spectrometry revealed a relatively high degree of unsaturation, 83.32% and 16% for saturated fatty acid, with a linoleic acid content of 63.66% followed by oleic 18.34%, palmitic 12.84% and stearic acid 2.81%. Based on these results, O. ficus-indica seed oil appears to be a good potential source of edible oil for human and (or) animal consumption. Our investigation describes that Tamri and Tafraout cultivars are not really a commercial viable fruit due to low total soluble solids value and highest seeds number per fruit. Against Mohammedia, Sidi Ifni M and Nador cultivars proved to have the highest fruit weight, very good total soluble solids value and low number of seeds, these cultivars can therefore be planted for both fruit production and for harvesting of cladodes for animal feed.