Effects of Salinity on Seedling Biomass Production and Relative Water Content of Twenty Sorghum (Sorghum biolor L. Moench) Accessions

摘要

Salinity is a continuing problem in the arid and semi-arid tracts of the world. It could be alleviated using irrigation management and/or crop management. However, the former approach is outdated and very expensive. Nevertheless, the latter is economical as well as efficient and it enables to produce salt tolerant crop lines. But prior to that there is a need to confirm the presence of genetically based variation for salt tolerance among different species or varieties of a particular crop at different growth stages. Thus, twenty lowland sorghum (Sorghum bicolor L. Moench.) accessions were tested during early seedling biomass production at 2, 4, 8 and 16 dS m-1 salinity levels. Distilled water (0 dS m-1) was used as a control. Data analysis was carried out using jmp5 statistical software (version 5.0). Seedling Shoot Fresh Weight (SFW), seedling Shoot Dry Weight (SDW), seedling Root Fresh Weight (RFW) and seedling Root Dry Weight (RDW) were measured. The two ways ANOVA for accessions found statistically insignificant with respect to most parameters recorded (p>0.05) but it was significant with respect to RFW (p<0.001). On the other hand, the two ways ANOVA for treatments displayed statistical significance for all parameters at p<0.0001 except at p<0.01 for RFW. However, it was insignificant for accession*treatment interaction (p>0.05). Accessions such as 235461, 69239, 223550, 69029 and 23403 were found to be salt tolerant during seedling biomass production and in Relative Water Content (RWC). On the other hand, accessions 22885, 233247, 237264, 237265 and 237267 were found to be salt sensitive during seedling biomass production and in RWC. The rest sorghum accessions were intermediate in their salt tolerance. The study affirmed the presence of broad intraspecific genetic variation in sorghum accessions for salt stress with respect to their early biomass production and Relative Water Content (RWC).