Effects Of Seed Soaking With Chemical Regulators On Adzuki Bean Growth Under Phosphorus Deficient Conditions

The availability of P is one of the most significant determinants in plant growth. Plants depend almost exclusively on P absorbed from soil,most of the P applied to soil can be converted into unavailable forms that cannot be easily utilized by plants.So it is easy to cause the rhizosphere phosphorus deficiency, which has become a globally important restraint limiting plant productivity.Adzuki bean is widely planted in the northeast and northern parts of China and its quality can meet with market requirement of the world.Shanxi Province, one of China’s main areas of producing adzuki bean. But most of the soil in Shanxi Province is the calcareous soil in which the total phosphorus content is about 0.10% 0.15%.A great deal of researches shows that seed soaked with plant growth regulator or chemical regulator can make the morphology and physiology of crop more suitable to the adverse situation.Adzuki bean（Vigna angularis） c.v. Baohong 8824-17 was used in this study,these seeds were soaked with Sodium silicate（NaSiO₃）,lanthanum nitrate（La（NO₃）₃）,salicylic acid（C7H6O3）and calciumchloride（CaCl₂） was used to explore the morphology and physiology of crop more suitable to the adverse situation.The results are as follows:（1）With seed soaking with different concentration of C7H6O3 increased, leaf area of adzuki bean seedlings first increased and downward trend, while the root length of seedlings showed a on thecontrary trend.When the concentration of C7H6O3 is 150 mg/L, the root shoot ratio of adzuki bean seedlings fell to the lowest value. The chlorophyll content and carotenoid content of leaf increased as the concentration of C7H6O3 after showing the first increase then a downward trend, respectively, at the concentration of 150 mg/L,100mg/L.when the maximum value. After Soaking with C7H6O3, Fo of leaves worth to ease, Fm and Fv/Fm of seedling achieve a maximum,respectively, at the concentration of 100 mg/L and 150 mg/L.Under P deficiency condition,Seeds soaking with C7H6O3 will promote POD activity, root activity of seedling,compared with P deficiency condition,the MDA content showed varying degrees of decline, the phosphorus content of each part of the order of leaf > root> stem.（2）Seeds soaking with CaCl₂ to affect the performance of adzuki bean seedlings under phosphorus deficiency conditions to produce the plant height, root length, stem diameter of adzuki bean seedling were increased, seeds soaking with 1 g/L,1.5 g/L and 2 g/L CaCl₂ can alleviate the damage of leaf area of adzuki bean on phosphorus deficiency; the root fresh weight, root shoot ratio showed varying degrees of decline in phosphorus deficiency（0） condition.The chlorophyll content and carotenoid content of seedling increased with CaCl₂ concentration increased in first and then decreased; By the seeds soaking with 1.0 g/L,1.5g/L CaCl₂, the value of Fv/Fm, Fo,Fm ease better. Under P deficiency（0） condition, with the CaCl₂ concentration increased,the SOD activity, POD activity, root apase present increased at first and then a downward trend; MDA content and phosphatase activity of the seedlings showed varying degrees of decline, when CaCl₂ concentration was 1.5 g/L, the phosphorus content of root,stem and leaf of adzuki bean seedling were increased to the highest value.（3）Under phosphorus deficiency conditions,seeds soaking with La（NO₃）₃have a mitigation role in the plant height of adzuki bean seedlings,with the increased of seed soaking concentration, the root length of seedlings performance a complicated trends,when 150 mg/L of La（NO₃）₃,the root length of adzuki bean seedling reaches a minimum,With the increase of La（NO₃）₃concentration,the underground fresh weight of seedling increased first and then reduced, and the root shoot ratio of seedling increased at first and then decreased, the concentration of La（NO₃）₃was 100mg/L down to a minimum. When the concentration of La（NO₃）₃was 150mg/L,50mg/L,the chlorophyll content and carotenoid content of seedling remission best; After seed soaking with La（NO₃）₃, compared with Deficiency（0） condition,Fo value decreased,Fm, Fv/Fm values were increased in varying degrees;under phosphorus deficiency conditions（0） as La（NO₃）₃concentration increased,SOD activity, POD activity,root activity showing the first increase then a downward trend; MDA content, root apase showed varying degrees of decline compared with P deficiency（0）condition, when La（NO₃）₃concentration of 150mg/L, the root, stem and leaf of phosphorus content of seedlings were increased to the highest value.（4）Seeds soaking with different concentration of NaSiO₃ have a varying degrees about agronomic traits and biomass of the adzuki bean seedlings under phosphorus deficiency condition, when the concentration of NaSiO₃ was 200 mg/L, the plant height, root length,leaf area, chlorophyll content and carotenoids content of seedling alleviate the effect of the best; the root shoot ratio of declines degree also the largest,at this concentration, the photosynthetic fluorescence parameters such as Fo, Fm and Fv/Fm has reached the maximum extent alleviated. When the NaSiO₃ is 300 mg/L,the stemdiameter presented a best mitigation role; With NaSiO₃ concentration,the protective enzyme activity of adzuki bean seedlings such as SOD, POD and root activity present increased at first after downward trend; The MDA content, root apase showed a opposite trend;compared with phosphorus deficiency condition（0）,seeds soaking with different concentrations of NaSiO₃,phosphorus content of leaves increase in the largest.This test using Subordinate Function on different concentratio ns of substance on the P-deficiency was assessed about adzuki b eanseedlings resistant capability.With the increase of the chemical regulators substance conce ntration,the ease effect presented increased at first after downwa rd trend;The ease effect of Salicylic acid, lanthanum nitrate, sodi um silicate, calcium chloride,at the concentration of 150 mg/L, 150 mg/L, 200 mg/L, 1.5 g/L was better,respectively.The alleviate eff ect of different concentrations of chemical regulators substance i n the order: 150 mg/L of La（NO₃）₃> 200 mg/L of NaSiO₃>1.5 g/L CaCl₂.