Studies On Drought-Resistance Of Seedling In Different Bluegrass Cultivars

In this research , 9 bluegrass cultivars were collected :1 native bluegrass (Poapratensis Van anceps Gard, Bluegrass w) and the others were cultivars which were used usually in the north.In the test,the method of drought continually was adapted, and associated field experiment and analysis in the lab, researched the effects of drought on the physical and chemical characteristics, morphological characteristics of bluegrass seedling, the same time, determined the effect of drought on the germination force ,last, 9 cultivars were categorized by drought-resistance. The main results were showed as following:1. Seeds were treated by PEG, low concentration 0.025mg/ml advanced the germination , but as high concentration 0.05mg/ml, 0.075mg/ml, 0.10 mg/ml, the germination was inhibited, and the inhibition degree aggravated with PEG concentration increased .difference was evident among 9 bluegrass cultivars.2. The relative water contents of leaves in 9 cultivars treated decreased compared with ck, the amount decreased was increased gradually. After watered again, the relative water contents of leaves recovered, difference was marked among the cultivars.3. The lost water rate of leaves of left body of 9 cultivars treated decreased compared with ck within 14 days during drought, increased as 21 days. After watered again , the lost water rate of left of leaves decreased compared with ck, too, and lowed greatly.4. The relative electrical conductivity rate(%) of the leaves increased in 9 bluegrass cultivars treated by drought, increased gradually with time . After watered again, the relative electrical conductivity rate(%) of the leaves recovered among 9 cultivars treated with them which were 21 days under drought, but did not reach identical level with ck.5. The chiorophyll contents of leaves were greater than ck among 9 cultivars within 14 days, with the exception of the Bluegrass w,less than ck as 21 days. After watered again .excluding the Bluegrass w, the others were less than ck too.6. The free proline contents of the leaves were accumulated quite a lot by drought among 9 cultivars treated , and increased with time of drought . After watered again, recovered compared with those of 21 days of drought , change was distinctive , but did not reach identical level with ck.7. The root dry mass accumulation was inhibited by drought among 9 cultivars treated, the root dry mass lowed, and the amount decreased was greater with time. After watered again, recovered compared with those of 21 days of drought.8. The root activity of 9 cultivars treated was less than those of 7 days of drought, excludingNassau, Bluechip. was greater than ck as 14 days of drought, all were less than ck ,as 21 days of drought. After watered again,Award.Fortuna, Park, Balin were less than ck, the others were greater than ck.9. Fig I and II illustrated: the stomata opening of Bluechip , Bluegrass w of 21 days of drought was smaller than its of 7 days, the root hairs amount of 21 days were fewer than those of 7 days.10. Drought resistance synthesis appraisement among 9 bluegrass cultivars, the cultivars were categorized 3: 1 . (relative drought resistance) Bali, Par, Bluegrass w, Merit; 2.( drought resistance average )Fortuna;3.( relative sensitivity )Connk Nassau,Bluechip, AwardPostgraduate: Feng Shuhua Major:Fruitwood ScienceAdvisonProf.Chen Yajun...