干旱区生态环境知识资源中心

To determine limits of tolerance, provide information about genetic diversity, and explore potential as progenitors for a salt-tolerant wheat improvement program, we collected several landraces and genotypes reputed to be salt-tolerant. Salt tolerance was tested by irrigation with a diluted solution of seawater with 12 dS.m(-1) electrical conductivity for two years. Phenotypic parameters of percent of emergence, days to flowering to spike emergence, and physiological maturity were not significantly affected. Leaf area was sensitive to salt stress and inhibited about 30%. Plant height was inhibited 30%, while spike length and number of grains per spike were not. Total yield of Shorawaki and Kharchia landraces confirmed their reputation as salt-tolerant. Cultivars Mepuchi, Pericu, Calafia, WH157, and SNH-1 were inhibited at a moderate level of tolerance; cultivars Cochimi, Lu26S, and KRL 1-4 were inhibited, as was the control cultivar Oasis by up to 50%. To amplify microsatellites from genomes A, B, and D, 33 pairs of primers were used. The microsatellite WMS169-6A was highly polymorphic, with 10 different alleles distinguishing the genotype set. Also, the short arm of chromosome 4D microsatellites were amplified and found to be monomorphic, which suggests highly conserved alleles. The other microsatellites had variable polymorphism. In total, 120 alleles were obtained and used to define genetic diversity. The resulting dendrogram showed that landraces Shorawaki and Kharchia are distantly grouped from all other cultivars, as well as the cultivar Chinese Spring. Strikingly, KRL1-4, a derivative of Kharchia, did not show a close relationship to its source. The geographic origin did not influence pair-wise combinations. However, pedigree did influence pair-wise combinations.