| This study was conducted from 2013 to 2014 in the agronomy experimental station and State Key Laboratory of Crop Biology of Shandong Agricultural University,Taian,China.With two hundred and twenty peanut germplasm of five botanical types grown under drought treatment and natural water control at pod-setting stage.With mature pods yield drought-resistant coefficient of peanut germplasm was identified.The relationship between drought resistance of peanut germplasm and antioxidant capacity and morphological structure of leaves were analyzed. The drought resistance characters of different peanut germplasm were parsed.Main results were as follows. 1 Evaluation and identification of drought resistance of peanut germplasmThis research adopted drought resistance coefficient(yield of drought drought conditions/yield of natural water conditions) as indicator to evaluate drought resistance of peanut germplasm.The drought resistance was 0.64 to 1.33.The drought resistance of peanut germplasm can be divided into 3 grads Based on contrast varieties:high-resistance,including 57 varieties like Rugaoxiyangsheng, A596, shanhua 11, shanhua 9, 0616(E1), nongda 831,shanhua 17,fenghua5,luhua 11,shanhua 7,shanhua 13 and so on;mid-resistance,including 80 varieties like fenghua 1,huayu 25, yuhua 15, jihua 4, nongda 818,haihua 1, fenghua 2, fenghua 6, shanhua 14, 79266 and so on;weak-resistance,Including 83 varieties like baisha 17, baisha 1016-1, ICG446, baisha 13-1, silicai(1), jihongtianyidianbai and so on.Drought resistance of the germplasm are concerned with its botanical types,The highest drought resistance coefficient of average is Intermediate by 0.95, followed by var. Hirsuta,var. Hypogaea, var. Vulgaris, var. Fastigiata is the lowest by 0.78. 2 The relationship between drought resistance of peanut germplasm and antioxidant capacity of leavesUnder natural water control at pod-setting period of peanut germplasm, the SOD activity of var. Vulgaris is highest, Intermediate followed,var. Hirsuta is the lowest, and drought resistance is not significantly associated with it.Under drought stress condition at pod-setting period of peanut germplasm,the SOD activity of var. Vulgaris is highest also,and var. Hirsuta is about the same,var. Fastigiata is the lowest.Drought resistance is related significantly associated with SOD activity and its increase range under drought stress condition at pod-setting period, so the SOD activity of drought resistance of germplasm after drought stress significantly increase. Drought resistance of germplasm is negative correlation with the POD activity of leaves under the natural water condition, and related significantly associated with the POD activity of leaves under the drought treatment condition.The highest CAT activity and growth is var. Hirsuta,var. Hypogaea is followed,POD activity of the var. Hypogaea and var. Vulgaris declines after drought stress.The var. Fastigiata is in the middle,POD activity change smaller after drought stress.Correlation analysis showed that drought resistance were not significant with CAT activity and its growth.MDA content of leaves have different increased after drought stress, the Intermediate and var. Hirsuta small increase, var. Fastigiata is the largest.Drought resistance is related significantly associated with the MDA content and its increase under drought stress and control.In conclusion, strong drought resistance varieties under drought stress can induce the SOD activity, POD activity, CAT activity increase, enhance the antioxidant capacity, so as to reduce the accumulation of MDA, prevent oxidation damage.3 The relationship between drought resistance of peanut germplasm and leaf organization structureDrought resistant was closely related to palisade tissue thickness, the ratio of spongy and palisade tissue thickness, leaf tissue compact and stomatal opening degree, different types performance differences.The var. Hirsuta has advantages in leaf thickness,palisade tissue thickness and stomatal opening degree;Intermediate has advantages in the ratio of spongy and palisade tissue thickness.The morphology and structure of leaves in different germplasm were different.The difference of palisade tissue thickness, the ratio of spongy and palisade tissue thickness, leaf tissue compact are almost the same with the difference of drought resistant.So the high palisade tissue thickness, the ratio of spongy and palisade tissue thickness, leaf tissue compact in strong drought resistance germplasm to maintain high water state in the leaf.Stomata opening of different germplasm is closely related to drought resistance,show that the big stomatal opening of strong drought resistance germplasm can explain high photosynthesis of leaf. 4 Leaf drought resistance mechanisms of peanut germplasmDifferent germplasm have different leaf drought resistance mechanisms.Rugao xiyangsheng and Shanhua 11 have outstanding performance in antioxidant capacity of leaves and leaf organization structure.Shuanhua 15 has bigger ratio of spongy and palisade tissue thickness and SOD and CAT activity increased under drought stress;Shanuha 12 has bigger ratio of spongy and palisade tissue thickness,leaf tissue compact, stomatal opening degree and POD activity increased under drought stress; The SOD and POD activity of A596 increased under drought stress;Fenghua 5 has bigger ratio of spongy and palisade tissue thickness, leaf tissue compact and SOD activity increased under drought stress;Yinan silicao and Feixian silicao have bigger palisade tissue thickness and SOD activity increased under drought stress.African germplasm has bigger stomatal opening degree and SOD activity increased under drought stress;Luhua 11 has bigger ratio of spongy and palisade tissue thickness and SOD activity increased under drought stress;Fenghua 3 has has bigger stomatal opening degree and CAT activity increased under drought stress,that they drought.But Baisha 1016 Jihongtianyidianbai and silicai have smaller stomatal opening degree and SOD activity declineed under drought stress,that they don’t drought. |
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