Studies On Drought Resistance In Different Bluegrass Cultivars

Twelve varieties of bluegrass are used as serve material in experimentation. The method of continue drought 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 seeding, the same time, determined the effect of drought on the germination force under different thickness of PEG(-0.2MPa, -0.5MPa, -1.0MPa). At last, 12varieties were categorized by drought resistance. The main results were showed as following:1 Vagermination rate of all varieties fall expect Merit and Liberator, theirs raised in low-grade intimidation, seminal vagermination rate descend with intimidate degree's aggravation in some drought degree. It is appropriated to mensurate drought resistance in midding-intimidation.2 Moisture intimidation make plant growth rate droped in whole drought stage, The bigger of drought degree, the slower of plant grow. The weight of root descend with drought time last. The weight of root has relation with water using of plant.3 The relative water contents of leaves in 12varieties fall with aggravation of drought resistance.The lost water rate of leaves of left body in 12 varieties increased with time(2h, 4h, 8h) last in different treatment phase. (7d, 14d, 21d, 28d).The difference in varieties is biggest in drought 14d and leaves without body for 2h.4 The membrane permeability and free praline increase compare with antitheses, and increased with drought degree enhance and time last. The change of free praline can be used drought resistance index. The chlorophy II contents of leaves increase in some range under adversity, and descend while intimidate aggravate. The peroxidase (POD) contents increase compare with antitheses. The CAT is abduction in early stage, the CAT of some varieties is higher than antitheses, but increased percent of treatment to antitheses show descent in whole stage.5 Drought resistance of most varieties show consistent in germination and in seeding. But some is not so .for example, Balin's is weak in germination while good in seeding. Nassau and Conni show strong in germination while weak in seeding. It show one varieties has different resistance in different procreate stage.6 Colligating drought resistance of 12 varieties in germination and seeding to evaluate drought resistance of all varieties, the result is :First degree(comparative resist )Numerit, Park, Rugby2, Glade, Conni, Merit. Second degree (midding resist): Nassau, Liberator, Balin. Third degree(comparative sensitivity): Bluemoon, Blue Chirp, Nuglade.