| Soil salinization is one of the main limiting factors for agricultural production and high and stable yield of crops,In order to further understand the physiological mechanism of salt and alkali tolerance in maize,the photosynthetic characteristics,root system,antioxidant enzymes,biomass and other Heterosis of maize seedlings were compared under salt-alkali and non salt-alkali conditions,It provides a reference for the identification of salt-alkali tolerance and salt-alkali tolerance of maize varieties.Seven famous inbred lines were crossed through 4×3 NC-II design,12 crosses(including famous varieties:Zhengdan 958,Nongda 108,Shidan 19,SC704)were designed.Total of 19 accessions were tested by pot culture,and the physiological indexes of maize were measured at the seedling stage(three leaves and one heart).The test results show that:The morphological indexes used in this experiment include the height of maize seedling,the area of leaf,the weight of the dry matter of shoots and roots.The photosynthetic indexes include chlorophyll content,transpiration rate and stomatal conductance.Root index includes root length,surface area,root volume,root tip number,specific surface area and active absorption area.The anti inverse physiological indexes include SOD activity,POD activity,CAT activity,soluble protein content,etc.A series of indexes were different between the two soil conditions,so it could be used as the main physiological index to identify the salt tolerance of maize.Under the stress of salt-alkali,the morphological indexes of maize decreased and the decrease of leaf area was the greatest,while the decreases in the weight of the dry matter of shoots is the smallest.In addition to the weight of root dry matter,the decrease of the other three indexes in hybrids was less than that in inbred lines.The enzyme activity of maize increased under salt-alkali stress,and the increase of CAT activity was the largest,while the increase of SOD activity was the smallest.The increase of the activity of SOD and POD in the inbred lines was greater than that in the hybrids,and the increase of CAT activity and soluble protein content in the hybrids was greater than that of the inbred lines.The root index of maize decreased under salt-alkali stress.Except for active absorption area,the decrease of the other indices of the hybrid species was higher than that of the inbred lines.In addition to the dry weight of the shoot,the heterosis of maize morphology increased under saline-alkali stress,while the heterosis of maize photosynthetic index decreased.The heterosis of SOD and POD activity decreased under saline alkali stress,while the heterosis of CAT and soluble protein increased.In addition to active absorption area,the heterosis of maize root index was reduced.The broad heritability of maize morphology,photosynthesis,enzyme activity and root system were all larger than those of narrow heritability.These traits had prominent non additive inheritance,and could be selected in the early generation.The shoots dry matter weight and leaf area,root dry matter weight and root length,root volume,root surface area,chlorophyll and stomatal conductance,specific surface area and root tip number,SOD activity were positively correlated with POD activity.The root dry matter weight and POD activity,CAT activity were negatively correlated with root length,root surface area and root volume.Shoot dry weight and root dry weight,root dry weight and root number,plant height and leaf area,root volume and root tip number,transpiration rate and stomatal conductance,chlorophyll,root length and root surface area,root volume,root number,root surface area and root volume and root number were very a significant positive correlation.The specific surface area has a very significant negative correlation with the activity of POD. |
PDF Full Text Request