苗期干旱胁迫对不同抗旱花生品种生理特性、产量和品质的影响

在人工控水条件下，研究了两个不同抗旱花生品种苗期干旱下的生理特性及其产量和品质。结果表明，随着干旱程度的增加，两品种叶片光合速率(P_n)逐渐下降，丙二醛(MDA)含量增加；解除干旱后，叶内MDA含量降低，Pn很快恢复到或超过对照水平，农大818的恢复能力强于鲁花11。适当干旱处理，可增加叶片中超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)的活性，提高叶片可溶性蛋白质(P_r)含量，鲁花11以中轻度干旱（灌水60~80 mm），而农大818以中度干旱（灌水40~60 mm）时酶活性最强、Pr含量最高，同一干旱处理、特别重度干旱（灌水20 mm）处理的酶活性，农大818明显高于鲁花11；解除干旱后，两品种叶中SOD、POD、CAT活性和Pr含量显著降低，但农大818的酶活性仍高于鲁花11。随着苗期干旱程度的增加，花生荚果和籽仁产量降低，但农大818的降幅小于鲁花11；若苗期灌水量低于60~80 mm则影响产量。花生苗期中、轻度干旱胁迫可增加籽仁蛋白质含量，而对脂肪含量的影响不大；重度干旱明显降低籽仁脂肪含量、脂肪中油酸组分和O/L比值，增加亚油酸组分，但对蛋白质的影响较小。鲁花11以60~80 mm水分处理及农大818以40~60 mm水分处理时籽仁品质最佳。

Effects of Drought during Seedling Stage on Physiological Traits, Yield and Quality of Different Peanut Cultivars

Peanut is one of the ideal crops in dry farming.Drought is the main limit factor of peanut to increase yield and improve quality.Seedling stage is constantly hit by drought for summer peanut.In order to understand the suitable watering amount at peanut seedling stage,provide theoretical basis and technique for dry farming peanut producing the experiment was conducted with drought light-resistant peanut cv.Luhua 11 and drought resistant peanut cv.Nongda 818 from 2003 to 2004 in the experimental station of Shandong Agricultural University.Five treatments with watering 20 mm(serious drought stress),40 mm(middle drought stress),60 mm(slight-middle drought stress),80 mm(slight drought stress), and 100 mm(CK) were made at 10 days after seedling(27 June) with three replicates in a randomized block design.The drought stress stopped at full-bloom stage(20 July) and then all treatments were irrigated 100 mm water at full-bloom stage,pod-setting stage and pod filling stage separately.The results showed that the photosynthesis rate(P_n) decreased,and malondialdeyde(MDA) content increased remarkably with the drought degree raising.After rewatering,the MDA content decreased and P_n returned to the level of check rapidly,the recovery ability of Nongda 818 was bigger than that of Luhua 11.Suitable drought treatment could enhance the activities of superoxide dismutase(SOD),peroxidase(POD) and catalase(CAT),and increase the soluble protein content.The highest activities of SOD,POD,CAT,and soluble protein content presented at the slight-middle drought treatment(watering 6080 mm) for Luhua 11,but at the middle drought treatment(watering 4060 mm) for Nongda 818.At the same drought treatment,especially at serious drought treatment(watering 20 mm),the activities of SOD,POD,CAT of Nongda 818 were significantly higher than those of Luhua 11.After rewatering,the activities of SOD,POD,CAT and soluble protein content reduced significantly,but the activities of SOD,POD,CAT of Nongda 818 were still higher than those of Luhua 11.With the drought degree raising,pod and kernel yields substantially decreased and the yield losses of Nongda 818 were less than that of Luhua 11.The irrigating amount at peanut seedling stage is no less than 6080 mm to avoid the yield loss.Middle and slight drought stress at seedling stage could increase the protein content of peanut kernel,and have a little effect on fat content.Serious drought stress at seedling stage decreased oleic content and the ratio of oleic/linoleic(O/L) significantly,increased linoleic content of peanut kernel,and had a little effect on protein content.The optimal irrigating amount at seedling stage for the best kernel quality of Luhua 11 is 6080 mm and that of Nongda 818 is 4060 mm.