Different responses of wheat with different chromosome ploidies to water stress during seed seedling transformation

摘要

In this study, seed germination, seedling growth and seed reserve utilization of three wheat species including Triticum boeoticum (diploid), T. dicoccoides (tetraploid) and T. aestivum (hexaploid), were investigated at different drought levels (osmotic potentials of 0, -0.3, -0.5 and -0.7 MPa). The objectives of this study were to characterize the evolutional tendency and assess the genetic variable response of germination characteristics and seedling growth to different drought levels in wheat from diploid to hexaploid. The results indicated that the one-hundred-seed weight, germination percentage, mean germination time, root length and root/shoot ratio of diploid wheat were significantly lower than those of tetraploid and hexaploid wheat (p<0.05), but germination index notably higher than that of tetraploid and hexaploid wheat (p<0.05), and there were no significant differences of these indexes between tetraploid and hexaploid wheat (p>0.05). With the evolution of wheat from diploid to hexaploid, the seed reserve depletion percentage (SRDP) of wheat remained a downward trend. However, opposite status (increased) showed in the seed reserve utilization efficiency (SRUE) of wheat. Moreover, the weight of utilized seed reserve and seedling dry weight of wheat exhibited diploid