The evaluation of new drought tolerant germplasms in Russian wildrye (Psathyrostachys juncea) by space breeding

Twentyfive Russian Wildrye (Psathyrostachys juncea) germplasms were selected from the first generation individuals developed from space flight seeds to test the drought tolerance by using the relative water content, MDA content, proline content and soluble sugar content The results of this study showed that the height of individual 15, 21 and 24 were higher than that of others, leaf length of individual 15, 21 and 11 were longer than that of others, leaf width of individual 21, 7 and 17 were widest, and that cover of individual 10 and 21 was biggest. The individual 1 and 3 maintained higher relative water content under drought environment and the individual 2, 3, 6 and 23 showed the soluble sugar content. The MDA content in 11 and 12 individuals was lower and the proline content in 11 and 24 individuals was higher. The cluster analysis showed that 25 germplasms of Russian Wildrye were divided into three groups by drought tolerance, indicating that 23, 25, 24, 10, 21 and 15 fell into the group with stronger drought tolerance, 11 and 22 showed the medium drought tolerance, and that the weaker drought tolerance group included 12, 13, 16, 6, 7, 2, 3, 4, 8, 17, 19, 1, 20, 5, 14 and 9，the weakest drought tolerance group included 18.