Studies On Salt-tolerance Of Spring Wheat In Heilongjiang Province

Soil salinization was a global ecological problem, caused output reduction of multiple crops inthe worldwide and had become one of main factors that restricted agricultural production of Chinaand the world. Wheat was one of the world's most important food crops, like others, the wheat'syield was seriously restricted by soil salinization. Selecting, identifying and spreading salt-tolerantwheat varieties could greatly increase wheat yield; it was of great theoretical and practicalsignificance to develop and use saline soil, broaden wheat hereditary basis, select the newsalt-tolerant gene, expand wheat-cultivated area and improve unit yields. Forty four spring wheatvarieties(lines) of Heilongjiang Province were taken for tested materials in the experiment,NY/PZT001-2002＜technology standards of wheat salt-tolerant identification and evaluation ofthe Agricultural Ministry＞was for criteria, CDH was for salt-tolerant varieties control and Chinaspring was for salt-sensitive varieties control in the study of wheat salt-tolerance at shoot andseedling stages. Studies on physiological and biochemical mechanism of wheat salt-tolerance withwater culture under soda salt stress aimed at analyzing Heilongjiang Province salt-tolerant springwheat varieties, exploring physiological and biochemical indexes of salt-tolerant wheat andproviding a reference for breeding salt-tolerant wheat and salt-tolerant identification. The results asfollows:1. The primarily identification results of forty-four salt-tolerant materials of spring wheatindicated: most tested materials were not salt-tolerant. The varieties that the salt-tolerant level atshoot stage was level one were LM26, KHI4 and BM2; the varieties that the salt-tolerant level atshoot stage was level two were KD4, KH17 and KD7. The varieties that the salt-tolerant level atseedling stage was level two were LM26 and BM2, the varieties that the salt-tolerant level atseedling stage was level three were KH14 and KH17, and other tested materials were notsalt-tolerant at shoot and seedling stages.2. At the same press time, the root length of various materials was downtrend as the saltconcentration increased. The high salt-tolerant materials decreased slowly, the salt-sensitivematerials decreased rapidly; the middle salt-tolerant materials decreased with the extent betweenthe two formers. There were significant differences in the root length of the tested materials underthe same press time and salt concentration.3. At the same press time, the seedling height of various materials was downtrend as the saltconcentration increased. The high salt-tolerant materials decreased slowly, the middle salt-tolerantmaterials decreased secondly, the salt-sensitive materials decreased rapidly. There were significant differences in the seedling height of the tested materials under the same press time and saltconcentration.4. The membrane permeability of leaves increased gradually as the salt-press concentrationand time increased. The membrane permeability of leaves was highest at the salt concentration of30mmol/L or 40mmol/L. The high salt-tolerant materials increased lest, the salt-sensitive materialsincreased most, the middle salt-tolerant materials increased with the extent between the twoformers. There were significant differences in the membrane permeability of leaves under the samepress time and concentration.5. At the same press time, the SOD activity of various materials was higher firstly and wentdawn gradually as the salt concentration increased. The SOD activity was highest at the saltconcentration of 30mmol/L, The high salt-tolerant materials changed most, the salt-sensitivematerials changed lest, the middle salt-tolerant materials changed with the extent between the twoformers. There were significant differences in the SOD activity under the same press time andconcentration.6. At the press time of seven days and fourteen days, chlorophyll contents of the highsalt-tolerant materials were higher firstly and went dawn as salt concentration increased, themaximum value was in low salt concentration. The salt-sensitive materials decreased gradually. Atthe press time of twenty-one days, all materials were downtrend. There were significant differencesin the chlorophyll contents under the same press time and concentration.