Studiesof Regulatory Of Phthalanilic Acid On Growth And Development Of Cowpea

Phthalanilic acid is a new plant growth regulator,but its regulation mechanism for plant growth and development is unclear,which limits the further application of the pharmaceutical.To study the mechanism of the agent,taken cowpea as experimental crop,brassinolides as the contrast agent,the influence ofdifferent concentrations(266.7 mg/L,200.0mg/L and 133.3 mg/L)ofphthalanilic acidthrough observing the change of the photosynthesis,stress resistance,yield and fruit quality of cowpea were stuidied.The effect of phthalanilic acid on the growth and development of cowpea was evaluated to provide a basis for its application.The main findings are as follows:(1)Photosynthesis was significantly enhanced after spraing phthalanilic acid.The results showed that200.0 mg/L was the most effective concentration of phthalanilic acid to enhance photosynthetic rate of cowpea.The photosynthetic rate of cowpea increased by 12.53% in the early stage of pods and the chlorophyll content increased by 7.28%-24.62%.(2)It can induce cowpea to improve stress resistance.SOD,CAT and POD in the leaves of cowpea were increased by 1.67%-7.47%,17.06%-45.88% and 22.35%-51.64%,respectively under the concentration of 200.0 mg/L,and reached the highest level at 11 days after the treatment.The content of free proline(Pro)could be increased by 80.70% compared with the blank control.MDA content and relative conductivity were decreased by 9.09%-22.32% and 14.77%-35.24% respectively compared with the blank control.(3)The pod rate and yield of cowpea were significantly improved.After spraing 200.0 mg/L concentration of phthalanilic acid,the pod rate of cowpea increased by 19.64% and the yield increased by 15.67%,which was significantly higher than that of blank control.The pod rate and yield were increased by 12.73% and 8.8% respectively that of brassinolide.(4)It can improve the quality of cowpea pods.After spraing 200.0 mg/L concentration of phthalanilic acid,the pod length and fruit weight were significantly increased by 18.7% and 15.94% compared with the blank control.The contents of VC,soluble protein,soluble sugar and water content were increased by 29.21%,3.86%,5.87% and 1.69%,respectively.But there was no significant difference in the width of pod width compare with that of blank control.The soluble protein content was increased by 30% compare with that of blank control,and 25.25% higher than that of phthalanilic acid.The results indicate that the phthalanilic acid can promote the growth and development of cowpea,induce it to improve the resistance,and have the effect of increasing production and improving the quality.The agent is worth practicing in production practice and is recommended to be sprayed at 200.0 mg/Lconcentration of phthalanilic acid.