A Study On The Drought-resistance Of Germination And Seedling For Silphium Perfoliatum L., Cichorium Intybus L.cv Puna And Rumex K-1

The drought-resistance in germination and seedling period on Silphium perfoliatum L, Cichorium intybus L. cv Puna and Rumex K-l were studied using PEG-6000 as water-stress or controlling the soil Related Water Content (RWC) in pot experiments. To enhance the drought-resistance, the methods which is by making seeds Moisture-Absorbing and Drying Again (MADA), soaking seeds and spraying their leaves with 0.1%CaCl2, were investigated in this study.Three treatments (CK, Soaked with 0.1% CaCl2, MADA) were given on three kinds of herbage seeds respectively. Then measured the germination percentage, the length of young bud and root of the seeds under different water-stress produced by 0, 5%, 10%, 15%, 20% and 25% PEG solution. After controlling the soil RWC to 80% (normal water supply), 60%( lighter drought-stress) and 40%( heavier drought-stress), the contents of free Proline, the soluble sugar and MDA in seedling leaves of three herbage which would be sprayed with 0.1%CaCl2 or not, were detected respectively.The main results were as follows:1 The germination percentage and the length of bud in all three kinds of seeds decreased with the increasing of water-stress. Ligther water-stress could stimulate the root growth in Cichorium intybus L. cv Puna and Rumex K-l.2 The germination restraint under water-stress were relaxed when the method of MADA and soaking seeds with 0.1%CaCl2 used in Silphium perfoliatum L. On the contrary, it had no effect on Cichorium intybus L. cv Puna and Rumex K-l.3 The contents of free Proline, soluble sugar and MDA in the leaves of three kinds of herbage were obviously accumulated with the drought-stress becoming heavier in pot experiment. In heavier drought-stress, free Pro in Silphium perfoliatum L,Cichorium intybus L. cv Puna and Rumex K-l were increased 44%, 28%, 372% resectively; and soluble sugar increased 37%> 62% and 87%; MDA were 332%, 275% and 386%.4 Spraying leaves with 0.1%CaCl2 under drought condition increased the contents of free Pro in leaves (P<0.01 or P<0.05) and decreased MDA significantly (P<0.01 or P<0.05), and enhanced the water retention capacity (P<0.05) in three kinds of herbage. The soluble sugar increased in Silphium perfoliatum L .and Cichorium intybus L. cv Puna (P<0.05), and Rumex AT-7.(P>0.05), after the leaves were sprayed with 0.1%CaCl2 in drought.5 A primitive conclusion about the capacity of drought-resistance in germination and seedling period maybe as follow: Rumex K-l> Cichorium intybus L. cv Puna> Silphium perfoliatum L.