脲酶抑制剂氢醌对大豆结瘤、固氮和木质部溶质氮形态的影响

Effect of Urease Inhibitor-Hydroquinone on Nodulation Activity of Nodule Fixd-N and Solution Nitrogen of Xylem Sap of Nodulated Soybean

首次报导了在白浆土和砂壤土上使用氢醌(HQ)抑制土壤脲酶活性,有效地缓解尿素分解产物及其随后的氧化产物对大豆结瘤和固氮活性的抑制效应,结果表明:1.HQ浓度在40PPM以内对大豆幼苗生长及初生结瘤表现促进作用;进一步提高HQ浓度将使大豆根系生长受阻变态而阻止结瘤。2.HQ(10—50PPM)提高了离体活性大豆根瘤类苗体悬液的耗氧量(79.4—86.1％)和琥珀酸脱氢酶活性(124.7—138.4％)。3.盆栽和田间试验证实,由于HQ缓解了尿素的分解,从而颇大减轻了尿素对大豆结瘤和固氮(乙炔还原活性)的抑制效应;通过大豆木质部中溶质氮形态(酰胺、酰脲和硝酸盐)的分析进一步证实了,大豆植株从根部向地上部运输的氮素形态同土壤氮转化强度和根瘤固氮强度(酰脲相对丰度)之间的紧密联系。4.由于麦秸还田土壤脲酶活性提高,故应提高HQ剂量;与此同时,通过麦秸的“氮因子效应”便能完全解除尿素对大豆结瘤固氮的抑制,并为大豆籽实发育提供了丰富的土壤氮源。

It is fristly reported that hydroguinone (HQ) as urease inhibitor used in the clay soil and the sandy loam soil, the measure could effectively alleviate the restraining affect to nodulation and activity of nodule fixed-N of nodulated soybean caused by urea hydrolysate and its followed oxidate. The results were showed as following:1 . There were no adverse effects on the growth of soybean seedings and the primary nodulation within the concentaticn of 40 ppm HQ; whereas, the number of primary nodulalion was significantly inhibited as HQ concentation increased over 40 ppm because the root system was deformed and the growing was contralled.2. HQ(10 to 50 ppm)could increased to the absorbing O2(79.4 to 86.1%) and the activity of succinic dehydrogenase (124.2 to 138.4%) in the active nodule isolated from the growing period of soybean.3 . Boths data from the experments of the pots and the small areas of fields suggested: as urea hydrolysis was alleviated by HQ, the number of dulation and activity of noduled fixed-N (acclylence reduction activity) were inhibited by urea was significantly decreased. The analysis of solution nitrogen form from the soybean xylem sap (amide, ureide and nitrification) further indicated the tight correlation between the nitrogen form of soybean plant translate from root to aboveground and the translate intensity of soil nitrogen or intensity of odule fixed-N (ureides relative abundance).4 . Because the soil urease activity was enhanced by applying the wheat -straw, the number of HQ might he increased, and meanwhile, the inhibi-tation of urea on the nodulation and activity of nodule fixed-N were totally removed by applying wheat-straw as the 'nitrogen factor effect' and provide abundant soil nitrogen resources were offered for the seed-growing of soybean.