棉 花 学 报 Cotton Science 2006，18(5)：279-283
Characteristics of Absorbing，Accumulating and Distribution of Na+ under the Salinity Stress on Cotton Abstract：Under the stress of NaCl，the main active infector is the cation(Na+). Na+ is absorbed and accumulated distinctively among the different organs such as root，stem，leaf within the various salinity-resisted genotypes of cotton. It is the root of salinity-sensitive genotype，the root and leaf of salinity-resisted genotype，or the leaf of the salinity-high-resisted genotype whose Na+ is absorbed and accumulated most highly. But Na+ absorbed by the whole frond is almost the same according to the stress environment，while there is different among the different organs. Under the stress of lower concentration of NaCl(0.2%)，Na+ absorbed in the salinity-sensitive genotype and the resisted or high-resisted genotype was 1.9 times and 2.9 times of the control，respectively；while under the stress of higher concentration of NaCl(0.4%)，Na +absorbed in the salinity-sensitive genotype，in the resisted and in high-resisted genotype is 3.6 times，5.2 times and 5.3 times of the control，respectively. Cotton is salinity-escaping-type in the germination period while salinity-high-absorbing-type in the later growth periods ， which suggests the resisted mechanism is staggered and in phases. Overall，the salinity-resisted mechanism of cotton is different from other crops such as wheat and barley.
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