Screening And Physiological Mechanism Of Suitable Intercropping Peanut Varieties

Northeast agro-pastoral ecotone is one of the main peanut producing areas in Northeast China.Peanut-maize strip inter-cropping is a pattern of intensive use of space and efficient planting.However,the shading effect of high-stalk maize is one of the main factors restricting the yield of inter-cropped peanut.There is a lack of relatively shade-tolerant peanut varieties in peanut production.In order to meet the urgent need for peanut production,shade-tolerant peanut varieties were screened from 24 main peanut varieties in Northeast China,providing theoretical basis and production reference for belt Inter-cropping of peanut and maize.In this experiment,24 main cultivars in Northeast China were used as test materials.Four rows of maize and six rows of peanut were inter-cropped in strips.The first and second rows shaded by maize were K1 and K2,respectively,while the middle row CK was not shaded by maize.A total of 24 cells were repeated three times.The morphological indexes,dry matter accumulation,net photosynthetic rate(Pn),stomatal conductance(Gs),transpiration rate(Tr),inter-cellular CO2 concentration(Ci),canopy PAR transmittance,leaf area index(LAI),yield and Yield Related Factors of peanut at different growth stages were determined and screened.The main results are as follows:1.Under strip inter-cropping conditions,the main stem height of Nonghua 18 was the highest at the needle stage and pod stage of peanut flowering,and the difference between the first and second lines shaded by maize and the middle lines shaded by maize was small,while the main stem height of Nonghua 16 was the lowest,and the difference between the first and second lines shaded by maize and the middle lines shaded by maize was large.Among the dry matter accumulation and distribution,Huayu 52 had the highest dry matter accumulation and Nonghua 16 had the lowest dry matter accumulation.2.Under strip inter-cropping,photosynthetic rate(Pn),stomatal conductance(GS),transpiration rate(Tr)of peanut varieties(lines)decreased,while inter-cellular carbon dioxide concentration(Ci)increased.Among them,the net photosynthetic rate(Pn)of Nonghua 18 was the highest,and that of Jinhua 15 was the lowest.Under maize shading,the first and second lines of peanut top effective light radiation are smaller than the middle lines,and the LAI of the side lines is lower than that of the middle lines.Therefore,the PAR transmittance of the first line and the second line is larger than that of the middle line.The PAR transmittance of Jinhua 15 is the lowest.The difference between the first line,the second line and the middle line is not obvious.Fuhua 23 PAR has the highest transmittance,and the difference between the first line,the second line and the middle line is obvious.3.Among the effects of shading on Peanut Yield and related traits under strip inter-cropping,Fuhua 17 had the highest yield of 100-fruit weight,and the difference between K1,K2 and CK was small,indicating that the effect of shading by maize was not obvious;Nonghua 13 had the lowest yield,while K1,K2 and CK had the greatest difference,and the effect of shading by maize was obvious.4.The membership function was used to identify and screen peanuts.The main stem height,dry matter accumulation,leaf area index(LAI),net photosynthetic rate(Pn)and100-fruit weight were used as reference indexes.Shade-tolerant peanut varieties(lines)are Nonghua 15,Nonghua 16,Nonghua 20,Nonghua 12,Nonghua 13,Nonghua 19,Jinhua 14,Jinhua 16,Jinhua 22,Fuhua 17,Fuhua 24,Huayu 20,Huayu 38,Tiehua 1,Tiehua 13;Shade-tolerant peanut varieties(lines)are Nonghua 18,Huayu 52,Jinhua 15,Nonghua 21,Jinhua 11,Fuhua 24,Nonghua 9,Fuhua 20.Among them,Nonghua 18 has strong shade tolerance,and its shade tolerance performance is the strongest;Nonghua 16 has shade tolerance,and its shade tolerance performance is the weakest.