【摘要】 以苎麻品种川苎11号为材料,采用盆栽控水试验,设置正常供水(对照)、轻度干旱、中度干旱和重度干旱,研究了苎麻旺长期干旱胁迫持续20天对苎麻光合特性和产量的影响。结果表明,干旱胁迫显著降低了苎麻叶片净光合速率(Pn)、气孔导度(Gs)和蒸腾速率(T r),胁迫程度越重,降低幅度越大。干旱胁迫显著提高了苎麻叶片的内在水分利用效率(WUEi)和气孔限制值(Ls),但WUEi和Ls在轻度和中度胁迫下上升,在重度胁迫下下降。苎麻Pn的降低在轻度和中度干旱胁迫下受气孔因素限制,在重度干旱胁迫下受非气孔因素限制。干旱胁迫显著降低了苎麻鲜皮出麻率和原麻产量,但苎麻可以忍耐较轻程度的水分亏缺。总之,干旱胁迫显著降低了苎麻的光合速率,并影响到苎麻的生长和纤维产量,影响程度与干旱胁迫程度的强弱密切相关。在生产中,旱情达到中度干旱时应及时采取抗旱措施,确保苎麻正常生长。更多还原

【Abstract】 Ramie "Chuanzhu 11" was planted in pots which were set 4 treatments(namely well-watered,mild-watered,moderate and severe drought stress) for 20 days in a rain-proof green-house,then photosynthesis and yield were analyzed.The results showed that drought stress led to a prominent drop in net photosynthetic rate(Pn),stomatal conductance(Gs) and transpiration rate(Tr).The severer the drought stress was,the quicker reduction of the three indexes was.However,drought stress led to a prominent increase in instantaneous water use efficiency(WUEi) and stomatal limits(Ls),both WUEi and Ls enhanced under mild and moderate drought stress,but subsequently dropped under severe drought stress.The observed gradually change in Pn,indicated that mild drought and moderate drought caused stomatal inhibition while severe drought caused non-stomatal inhibition.In addition,decreased photosynthetic activity inhibited the growth of plants and led to a noticeable decline of the stripped bast percentage and fiber yield.Nonetheless,ramie could withstand mild drought stress.In summary,drought stress decreased photosynthetic rate,growth and yield of ramie,and the extent of these variations was closely related with the intensity of the drought stress.Therefore,when the field soil is under a moderate drought condition,mitigation measures must be timely taken in order to ensure the normal growth of the plants.更多还原