Impact of Salinity on Seed Germination and Early Seedling Growth of Three Sorghum (<i>Sorghum biolor </i>L. Moench) Cultivars

Abstract

The environmental stress such as, salinity (soil or water) are serious obstacles for field crops especially in the arid and semi-arid tracts of the world. In the Sudan, with the rapid expansion of irrigated agriculture, the question of soil salinity is becoming more and more urgent for naturally salt-affected lands under cultivation and maintaining the productivity of existing irrigated areas. It could be alleviated using irrigation and crop management. However, the former approach is very expensive. The latter is economical as well as efficient and it enables to produce salt tolerant crop varieties. Also other is a need to confirm the presence of genetically based variation for salt tolerance among different varieties of a particular crop at different plant growth stages. In order to investigate salinity stress on sorghum germination indices, an experiment was carried out in Sudan from September 2011 to October 2011 at University of Kordofan, in the Crop Sciences Department Laboratory, to create salinity stress, sodium chloride (Na Cl) at the levels of 0 (as control), 2, 4, 8 and 16 dS/m and three sorghum (Sorghum bicolor L. Moench) cultivars (Arfagadamak, Wad Ahmed and Butana) were tested. Seed germination percentage, seedling root dry weight and seedling shoot dry weight were measured. Low level of salinity (2 dS/m) increased seed germination percentage, while the high levels (4, 8 and 16 dS/m) inhibited the seed germination significantly. The strongest inhibition of germination occurred at the higher salt concentrations. Growth of young seedlings was also reduced, especially at the higher salt concentrations. Wad Ahmed cultivar was found to be salt tolerant during seedling biomass production. Arfagadamak and Butana cultivars were found to be salt sensitive during seedling biomass production. The study revealed the presence of broad intra specific genetic variation in sorghum varieties for salt stress with respect to their early biomass production.