Sensitivity of two wheat species's seeds (Triticum durum, variety Karim and Triticum aestivum, variety Salambô) to heat constraint during germination.

The aim of this study is determine the effect of different temperature regimes on germination of wheat seeds and early germination events. Germination is very sensitive to environment conditions, particularly the temperature. Physiological and biochemical responses of wheat seed germination during time at various temperatures (5, 15, 25, 35 and 45 degrees C) have shown that optimal temperature (25 degrees C) favorites a good aptitude to germinate, whereas low (5 degrees C) and high temperature (45 degrees C) were extend the delay of germination.

Anatomical and biochemical changes during adventitious rooting of apple rootstocks MM 106 cultured in vitro.

Adventitious rooting in microcuttings of Malus rootstocks MM106 was studied as regards their histological and biochemical aspects. Microcuttings from shoots raised in Murashige and Skoog's (1962) medium were transferred into a rooting medium containing IBA in the dark, then fixed 0, 3, 5, 7 and 10 days after. Some cambial zone and adjacent phloem cells became dense cytoplasm, nuclei with prominent nucleoli and the first cell divisions were observed at day 3.