Effect of Salt Stress on Pollen Tube Growth in Two <i>Medicago truncatula</i> Ecotypes

Abstract

Annual Medicago species contribute significantly to improved fodder production in Algeria. The leguminous plant model is Medicago truncatula Gaertner. Because of its high protein content, this plant is essential for natural soil fertilization as well as good quality nutrition for animals and humans. However, abiotic stresses such as salinity are the leading cause of land degradation and crop productivity limitations worldwide, and they have an impact on legume physiology and metabolism. We investigated the pollen tube growth behavior in two contrasting Medicago truncatula ecotypes under salt stress (Tru 42, tolerant, and Tru 242, sensitive) with different NaCl concentrations (68, 102, and 137 mM) because pollen tube growth mechanisms can be affected by environmental stresses such as water and salt stress. According to the data, the Tru242 ecotype has a pollen tube elongation of 1.41 to 8.45 um, whereas the high pollen tube elongation of the Tru 42 ecotype is between 2.8 and 18.83 um. It is crucial to comprehend the physiological reactions of male gametophytes in order to reproduce, as salinity stress can hinder their ability to do so. It is intriguing to include the tolerant genotype in a selection program for leguminous breeding, as the analysis revealed that the tolerant ecotype has better pollen tube elongation than the sensitive one. in fact, there is not enough knowledge about pollen tolerance mechanism to salt stress of Medicago truncatula or other Medicago species.

Keywords

• <i>Medicago truncatula</i>
• male gametophyte
• salinity
• legume