新疆短命植物小拟南芥耐盐性的初步研究

利用种子萌发及石蜡切片等方法对新疆短命植物小拟南芥(Arabidopsis pumila)在盐胁迫下种子的萌发率及植株生长发育的变化进行了研究,结果显示:(1)盐胁迫对小拟南芥种子萌发具有抑制作用,当去除盐分后,部分种子能够重新萌发.(2)盐分影响幼苗的形态及内部结构,低盐(50 mmol/L)时,幼苗基生叶较大且数量增加;叶中栅栏组织细胞大,排列舒展;根中导管数量明显增多,植株生长健壮而旺盛;而较高盐(150 mmol/L)时,叶片变小增厚,色深绿,底部叶变黄白色,叶中栅栏组织细胞窄小,排列紧密;根中导管数急剧下降,植株生长受到明显抑制.(3)盐胁迫对成株期植株的高度、花序轴长、角果数等性状都有显著影响,但在NaCl浓度达500 mmol/L时,植株仍然存活且有一定的结实率,显示此时的耐盐性比萌发期和幼苗期有显著提高.研究表明,小拟南芥从幼苗至成株期耐盐性逐渐增强,该特征与其对自然生存环境的适应相关.

Preliminary Study on Salt Tolerance of Ephemeral Plant Arabidopsis pumila in Xinjiang

Studies on the behavior of seed germination and plant growth and development of Xinjiang ephemeral plant Arabidopsis pumila under salt-stress were carried out.The results showed that(1) seed germination was inhibited during NaCl stress,but partial seeds would germinate after rehydration;(2)Salt-stress had effect on the shape and inner micro-structure of seedling.When in lower salt concentration(50 mmol/L),the size and number of basal leaves were larger and more than that of control(0 mmol/L);The palisade tissue cells were bigger and its arrangement was relaxed;The number of vessels in the root obviously increased,the appearance of the whole plant looked much vigorous.While in higher salt concentration(150 mmol/L),the leaf became smaller and thick,displayed dark-green color,leaves at bottom looked white-yellowish,nearly died;The palisade tissue cells were thin and small,and tightly arranged;The number of vessels in the root were few,and the growth of the plant was obviously inhibited;(3)Salt-stress affected plant height,inflorescence length,pods number per plant etc.apparently,but till NaCl concentration reached 500 mmol/L,the plant was still alive,and set some seeds,it indicated that the salt-tolerance at this stage was improved much more than that in seed germination and seedling stages.In conclusion,the enhancement of salt tolerance of A.pumila is compatible with its environment.