Interspecific Differences in Tolerance to Soil Compaction, Drought and Waterlogging Stresses among Maize and Triticale Genotypes

Stress susceptibility indexes ( SSI ) of eight maize and eight triticale genotypes for their ability to cope with soil compaction ( SC ) combined with drought (D) or waterlogging (W) were estimated through the determination of changes in dry matter of the shoot (S), root (R) and whole plant (S+R) grown at three levels of soil compaction (1.1, 1.3 and 1.6 g cm −3 ) and exposed to D or W stress for 7 or 14 days. The SSI values showed variation between and within maize and triticale genotypes, and it was possible to divide genotypes into groups of sensitive and resistant ones. The correlation coefficients ( r ) between stress susceptibility indexes of soil compaction ( SCSI ) and drought ( DSI ) or waterlogging ( WSI ) and between DSI and WSI were statistically significant. This indicates that genotypes resistant to soil compaction ( SC ) were resistant to drought (D) or waterlogging (W) stresses and that genotypes resistant to D were also resistant to W. Seedlings grown under the stresses showed changes in S to R ratio (S/R). Sensitive genotypes had higher S/R ratio than resistant ones. Decrease of S/R ratio depends on the duration of stresses, and it may be considered an adaptation mechanism to stress. After 7 days of recovery for D and W treatments, we observed only a partial return of growth traits to the level of control plants.