种植Bt玉米对土壤微生物活性和肥力的影响  

Effects of planting Bt corn on soil microbial activity and soil fertility

作　　者：王建武[1] 冯远娇[1] 

机构地区：[1]华南农业大学热带亚热带生态研究所,广州510642

出　　处：《生态学报》2005年第5期1213-1220,共8页Acta Ecologica Sinica

基　　金：国家自然科学基金资助项目 (3 0 2 70 2 7) ;广东省自然科学基金资助项目 (0 0 0 5 69;0 2 10 43 )~~

摘　　要：在温室种植比较了美国Bt玉米(34B2 4 (Mon810 ) )与同源常规玉米(34B2 3)、中国Bt玉米(12 4 6×14 82 (Cry1A) )与常规玉米(农大3138)对土壤微生物活性和肥力的影响。结果表明,两个Bt玉米品种5次取样(2 5、39、5 3、6 7、82 d)的根际土壤中都能检测到Bt蛋白,含量在2 0～80 ng·g- 1 dry soil之间。4个处理土壤硝化作用和精氨酸氨化作用强度在所有取样时期均没有显著差异;土壤蔗糖酶、土壤蛋白酶和酸性磷酸酶活性则分别只在2 5 d(农大3138<34B2 4与12 4 6×14 82 )、6 7d(34B2 4 >12 4 6×14 82和农大3138)和6 7d(34B2 4 >其它3个处理)存在显著差异;土壤脱氢酶、土壤脲酶和土壤呼吸强度则在多数取样时期多个处理间存在显著差异,说明其与玉米品种特性关系密切,其中,土壤脱氢酶和脲酶活性的差异在两个Bt玉米品种、Bt与同源常规品种(34B2 4与34B2 3)、Bt与常规品种(12 4 6×14 82与农大3138)以及常规与常规品种(34B2 3与农大3138)之间均没有一致的规律,但34B2 4与34B2 3处理的土壤呼吸作用强度高于12 4 6×14 82与农大3138,说明种植该系列品种的土壤中微生物总活性较高、土壤代谢旺盛。82 d后4个处理土壤有机质、NPK全量与速效养分含量均没有显著差异。本试验观测期种植Bt玉米并没有导致土壤微生物活性和土?Bt(Bacillus thuringiensis)corn is one of the four large-scale commercialized GM crops being planted around the world. The debate surrounding the potential ecological risk of Bt corn is ongoing because of the persistence of larvicidal Bt proteins in soil after release from Bt corn root exudates and/or by plant decomposition. The majority of published papers has examined the effects of Bt corn on cultivation of ecologically important soil microorganisms or has used non-cultivation based molecular genetic analysis of differences in microbial community structure. There are no reports on differences in soil activity and fertility between soils planted with a Bt-crop and the non-Bt parental or cultivars of the same crop. This study determines and compares differences in microbial activities and fertility of soils planted with two different Bt-corn varieties (34B24 and 1246×1482) and two non-Bt cultivars, including one non-Bt parental counterpart of 34B24 (34B23) and one non-Bt hybird (Nongda3138). Plants were grown in the greenhouse using a complete randomized block design. Samples were collected at different corn growth stages on days 25, 39, 53, 67, and 82. Soil microbial activity was assessed by measuring soil nitrification, arginine ammonification, and respiration of CO 2, and activity of the enzymes sucrase, acid phosphatase, dehydrogenase, and urease. Additionally, Bt protein contents in rhizosphere soil, organic matter content, total and available N/P/K in the surrounding soil were measured. Results showed that Bt protein concentration in the rhizosphere of one variety, 34B24, fluctuated between 46.593 and 76.943 ng dry soil g^(-1) throughout the season, whereas, there was a steady increase in concentration from 21.63 to 62.53 ng dry soil g^(-1) in the rhizosphere of the other variety, 1246×1482. In general, soil microbial activity and fertility indicators comparisons grouped into three categories. Firstly, soils planted with any of the corn varieties, Bt or non-Bt, were not significantly different in soil ni

关 键 词：BT玉米 土壤微生物活性 土壤肥力 土壤生态系统功能 

分 类 号：S513[农业科学—作物学]