Molecular and morphological evaluation of salt tolerance genes in advanced wheat lines (part 1)

Soil salinity is a key problem in cereal crops production that affects the metabolic activities as well as plant growth ultimately leading to plant death. Toxic effect of salinity can lead to reduced plant growth and yield. To counter these effects, tolerant varieties need to be developed that should be able to survive in saline conditions. Therefore, experiment was designed to evaluate yield and yield attributes of 29 advanced wheat lines with four check varieties in Randomized Complete Block Design (RCBD) with three replication. The research was conducted at National Agriculture Research Centre (NARC), Islamabad in 2013-2014 winter season. These lines have been bred for salt 'tolerant' traits in view to bring saline soils under wheat cultivation. The eleven morphological parameters studied in this experiment were significant at (p <= 0.05). An effective methodology was adopted for breeding programme to screen out genes that showed response to abiotic stresses using DNA markers. It was concluded from the correlation study that grain yield (kg/hectare) was significantly positive correlated with plant height (0.1802) but showed non-significant negative correlation with spike length (-0.1818), number of infertile spikelets per spike (-0.2352*), number of fertile spikelets per spike (-0.1121), and the number of fertile tillers, 1000 grain weight was significantly positive correlated with peduncle length (0.0019,), number of grains per spike (0.0823), grain yield per spike (0.0416) and showed negatively non-significant correlation with leaf area (-0.1357), number of infertile spikelets per spike (-0.1207), number of fertile spikelets per spike (-0.1523) and number of fertile tillers (-0.3135*).Morphological and molecular data confirmed that among all the 29 advanced wheat lines PA06B, PA02K, PA03B, PA02G and PA03C had the high potential for all the morphological parameters linked to the SSR markers. Five advanced wheat lines were selected on the basis of their high yield potential and its components and DNA markers linked to these morphological parameters compared with check varieties. Results of cluster analysis based on microsatellite data showed that the five genotypes were located in close proximity to each other in the same cluster but not clearly separated from the remaining 24 genotypes and check cultivars were also closely linked to these advanced wheat lines, all of which had been collected from the same habitat.