Regulation Effects Of Paclobutrazol On Physiological Characteristics And Yield Quality Of Different Source-sink Types In Peanut

Peanuts is one of the important oil crops and economic crops in my country.However,uncoordinated source library relations such as（redundancy of leaf source and polyunsaturated fruit,etc.）have seriously limited the improvement of peanut yield.Exogenous spraying of paclobutrazol is an important means of regulating peanuts in production practice,preventing planting and improving resistance and improving anti-pair,but its lack of system research on the regulation of different source-sink types in peanut.In order to explore the regulatory effects of paclobutrazol spraying at different stages on different source-sink types in peanut,field experiments and laboratory experiments were carried out in Shandong Agricultural University Agronomy Experiment Station and State Key Laboratory of Crop Biology in 2021.Taking source-sink coordination type Weihua 8,few sufficient source-few sink type Yuhua15 and large source-few sink type Huayu 33 as research materials,paclobutrazol was sprayed on the leaves at 15 days（15 d-PBZ）,30 days（30 d-PBZ）and 45 days（45 d-PBZ）after the beginning of flowering,the spraying concentration is 100 mg kg^-1,and 750 kg of liquid medicine sprayed per hectare,and the same amount of clean water（CK）was sprayed as the control.The effects of paclobutrazol spraying at different stages on the physiological characteristics and yield quality formation of different source-sink types in peanut,in order to further clarify the optimal spraying stage of paclobutrazol for different source-sink types in peanut.The main findings are as follows:1 Effects of paclobutrazol spraying at different stages on plant traits of different source-sink types in peanutSpraying paclobutrazol at different stages had effects on the agronomic traits and dry matter accumulation of different source-sink types in peanut.Spraying paclobutrazol 15 days after the first flowering is most beneficial to inhibit the main stem height and lateral branch length of Weihua 8,reduce the leaf area,and promote the accumulation of dry matter in the peanut pods;spraying paclobutrazol 30 days after the first flowering is beneficial to reduce the main stem height and lateral branch length of Yuhua 15 and Huayu 33,reduce the leaf area and leaf dry weight of peanut source organs（leaves）,increase dry weight of fruit and promote accumulation of dry matter in sink organs（pods）.However,spraying paclobutrazol45 days after the first flowering had no obvious inhibitory effect on the main stem height and lateral branch length of the three different source-sink types in peanut,significantly reduced the dry weight of Weihua 8 at harvest.2 Effects of paclobutrazol spraying at different stages on the physiological characteristics of different source-sink types in peanutSpraying paclobutrazol 15 days after the first flowering was beneficial to increase the chlorophyll content of peanut leaves of Weihua 8,increase the net photosynthetic rate,NR and SPS activities of leaves,and enhance the ability of peanut assimilation,compared with the control,the distribution rate of ¹³C assimilate in peanut pods was significantly increased by 49.73%;spraying paclobutrazol 30 days after the first flowering both increased the chlorophyll content and net photosynthetic rate of peanut leaves of Yuhua 15 and Huayu 33,increased the activities of NR and SPS,and accelerated the assimilation,compared with the control,the distribution rate of ¹³C assimilate to peanut pods increased by 34.01%and 37.70%respectively,which slowed down the phenomenon of leaf source redundancy.Spraying paclobutrazol at different stages inhibited the synthesis of GA₃in leaves of different source-sink types in peanut,decreased the content of IAA in peanut leaves,but increased the content of CTK;at the same time,spraying paclobutrazol at different stages increased the activities of SOD,POD and CAT in peanut leaves of different source-sink types,increased the soluble protein content of peanut leaves,and decreased the MDA content of leaves,which was beneficial to delay the senescence of peanut source organ leaves.3 Effects of paclobutrazol spraying at different stages on the yield quality of different source-sink types in peanutThe effects of spraying paclobutrazol on the pod yield of different source-sink types in peanut were different at different stages.Weihua 8 sprayed paclobutrazol 15 days after the first flowering to increase the yield the most,and its pod yield increased by 16.53%,mainly due to the increase of the number of fruits per plant and the rate of full fruit per plant;both Yuhua 15 and Huayu 33 were sprayed with paclobutrazol 30 days after the first flowering to increase the yield,and the pod yield increased by 6.06%and 23.46%,respectively.From the perspective of yield components,Yuhua 15 mainly increased the yield per plant.The number of fruit per plant and the rate of full fruit per plant were significantly increased in Huayu 33.Spraying paclobutrazol on 15 days after first flowering and 30 days after first flowering both increased the crude fat content of Weihua 8 and Yuhua 15,decreased the protein content,and increased the oleic acid content and O/L of Yuhua 15,but the oleic acid content and O/L value of Weihua 8 were reduced;the application of paclobutrazol at different stages reduced the crude fat and protein content of Huayu 33,and increased the oleic acid content and O/L value,the effect of spraying paclobutrazol was the most obvious 45 days after the first flowering.In summary,the peanuts may increase the number of monolarlozoles at different stages of peanuts and increased pods,and solve the problem of leaf source redundancy and more unsaturated problems to a certain extent,thereby increasing the production volume and improving quality of peanuts.Source-sink coordination type is suitable for spraying paclobutrazol at 15 days after the first flowering,which is beneficial to increase the yield and crude fat content of peanuts;few sufficient source-few sink type is suitable for spraying paclobutrazol at 30 days after the first flowering,which is beneficial to improve the peanut yield,crude fat content and O/L value;large source-few sink type suitable for spraying paclobutrazol 30 days after the first flowering is beneficial to improve peanut yield and O/L value.