Study of Morpho-Physiological and Biochemical Behavior of Cultivated Legume (Lens culinaris Medik Ssp culinaris) in Dry Area of Algeria

Abstract

The victory over the protein deficiency afflicting millions of human beings is a crucial and urgent task for world agriculture. The legume Lentil (Lens culinaris Medik) is one of the largest sources of protein with an average of 25% of all seeds produced worldwide. When used in crop rotation, it fertilizes the soil, as is the case in North Africa and this plant holds an important place throughout the world. In Algeria, lentil is largely growth in the semi-arid zones of the interior plains characterized by various abiotic constraints such as terminal drought which causes significant losses in lentil yield every year. For this purpose, the cases in this study aims to evaluate the effect of end of cycle water stress on the behavior of four varieties of lentil (Syrie 229, Metropole, Balkan 75 and Ibela) and to elucidate the plant’s morpho-physiological and biochemical parameters involved in tolerance and to assess varieties which could be grown under water stress conditions. The experiment was conducted in a laboratory and greenhouse with a well-controlled condition. The experiment was arranged in a completely randomized design of two factors (water stress and varieties) with four replications and two treatments. Not treated plants (without water stress application) were utilized as control. The four tested genotypes were subjected to two water regimes, one irrigated throughout the cycle (No stressed) used as a control, the other one stressful from the beginning of flowering till seed’s filling stages (stressed). The study covered the variation of the relative water content in leaves as well as the leaf surface, the rate of proline and soluble sugars of the leaves and the total seed protein content. The obtained results showed that the studied genotypes behaved differently to the water stress. Thus, a significant decrease was observed in the relative water content from 75.29% to 70.71% and in the leaf area from 16.76 cm2 to 13.63 cm2. An opposite behavior was observed on the osmoticum accumulated as a response to water deficit. A significant increase in proline (150.14 μg/g DM to 203.69 μg/g DM) and in soluble sugars stress (60.42 μg/g DM to 110.21 μg/g DM) was detected in leaves under stressed conditions. The terminal water stress resulted also in an increase in protein content in lentil seeds from a mean value of 22.08% to 24.84%. Regarding the obtained results, Metropole genotype seems to be the most tolerant cultivar to water stress followed by Balkan 755.