Studies On Effect Of Potassium On Phenolic Metabolism Of Wheat And Its Relationship With Dynamic Of Aphid Population

Pot experiment with three potassium level(k0:no potassium supplied, k1:0.1mg K2O was used in 1kg soil, K2O 0.15 mg K2O was used in 1kg soil)and two winter wheat cultivars (zhengmai9023and neixiang149) was conducted. And Dynamic of aphid population on two winter wheat was investigated. The difference of content of potassium, biomass, nutrition substance, phenolic substance and protective enzymes activities on various k level were compared. The relationship between aphid population and nutrition substance, phenolic substance were analyzed. The principle results were as follow.1. From anthesis to maturity, the k content in flag leaves was deline, while biomass tend to increase. K application could improve k content in flag leaves of wheat. The order of k content in flag leaves on three k level was k2>k1>k0. and the difference between of them was significantly. Compared to k0 and k2 level, biomass and yield in k1 level was higher, and there was no significant between k2 and k0 level. The obtained data indicated that k supplying optimized could increase k content in flag leaves which was helpful to accumulation of biomass and increase of yield. Wheat couldn't keep optimized status when k supplying excess or deficient.2. The investigation of aphid population on three k level suggested that k0 level aphid population peak was the highest, then was k2 and k1. Population peak could be increased when k used deficient or excess, and also the period of population peak was delayed. The aphid had longer time to infest wheat. k optimized supplied could ease the damage by decreasing aphid population and infestation time.3. Soluble sugar, sucrose and the free amino acid in flag leaves were raised when k supplied. These substances were highest in k1 level from anthesis to maturity. Significant negative relationship between aphid population and soluble sugar, sucrose and free amino acid had been found, the relationship coefficients were -0.958~-0.999*,-0.962*~-0.995**(Zhengmai9023),-0.952*~-0.999**,-0.954*~-0.999**(Neixiang149).respectively. While the relationshipcoefficients between sucrose and aphid population were various, ranged from no significant to significant. Thus, k affected aphid population by regulating content of soluble sugar, sucrose and free amino acid in flag leaves.4. K application increased protective enzymes (PAL,PPO,POD and TAL) activities and content of total phenol, phenol acid, and lignin in flag leaves. Compared to k0 and k2 treatment, the k1trentment had higher protective enzymes activities and content of soluble phenol, phenol acid,andlignin.There was negative relationship between aphid amount and content of soluble phenol, phenol acid,andlignin.the Wheat, Aphid, Potassium, Nutrition substance, Phenol substance, Dynamic of aphid population...