Evaluating salinity tolerance in progeny of domestic and wild barley crosses at the seedling growth stage

Abstract

Salinity is one of the most detrimental abiotic stresses affecting crop productivity worldwide. To identify barley (Hordeum vulgare L.) genotypes with satisfactory production under increased salinity, screening must focus on multiple phenological stages, specifically the earliest stages (germination and seedling), when plants are most vulnerable to stress. This experiment was conducted in a greenhouse to assess salinity tolerance of 161 genotypes (34 genotypes of 2× H. vulgare crosses; 116 genotypes of 4× H. vulgare crosses, and 11 parents). Beginning at the third leaf stage, seedlings were irrigated with solutions of 0, 100, 200, and 300 mM NaCl for 21 d.Analysis of variance showed significant effects due to genotype, salinity level, and their interaction for shoot dry weight (SDW). Overall, SDW showed negative association with plant height, whereas it was positively associated with tiller number, fertility, 100-seed weight, and grain yield. Mean SDW of all families decreased as salinity treatment level increased. Families varied in SDW and salinity susceptibility index (SSI) at 300 mM salinity treatment. Diploid Families 2 and 3 had the greatest SDW and lowest SSI (<1). Thirty percent of crosses from tetraploid Family 2 yielded the greatest SDW, whereas the same proportion of crosses from tetraploid Family 4 showed the greatest salinity tolerance as measured by SSI. These crosses, as well as the female parents, are valuable germplasm for improving salinity tolerance in barley breeding programs.

Effect of gibberellic acid on germination and seedling growth of Soybean (Glycine max L. Merrill)

“…However, seeds treated with a concentration of 150 ppm of gibberellic acid had superiori-ty in the percentage of laboratory germination, which means that they can give natural seedlings (high field emergence percentage). Thus, it meets the definition of AOSA seed vigor, which states that germination vigor includes those characteristics of the seed that determine the potential for rapid and uniform emergence and development of natural seedlings under a wide range of field conditions 10,15,17,26,27 . Moreover, the results indicate that the use of the growth regulator gibberellic acid had a significant effect on increasing the germination rate of soybean seeds and the percentage of field emergence due to the role of this hormone in stimulating the synthesis of enzymes necessary for germination and seedling vigor 14,27 .…”