文摘
Wheat (Triticum aestivum L.) has been found to possess allelopathic potential and studies have beenconduced to apply wheat allelopathy for biological weed control. 2,4-Dihydroxy-(2H)-1,4-benzoxazin-3(4H)-one (DIBOA) is a common product found in wheat, corn, and rye exudates and it can be releasedto the environment by that way. In this report, the stability of DIBOA is studied in two soils from croplands of wheat cv. Astron and cv. Ritmo. These varieties were selected by their concentrations ofDIBOA and 2,4-dihydroxy-7-methoxy-(2H)-1,4-benzoxazin-3(4H)-one (DIMBOA) from aerial parts andby the bioactivities of their aqueous extracts in the growth of wheat coleoptile sections. The degradationrate of DIBOA in these soils was measured in laboratory tests during 90 h by high-pressure liquidchromatography methods. These analyses demonstrate that DIBOA was transformed primarily into2-benzoxazolinone (BOA). This transformation was similar in both soil types with an average half-lifeof 43 h. The degradation studies for BOA show its biotransformation to 2-aminophenoxazin-3-one(APO) with a half-life of 2.5 days. Therefore, BOA is an intermediate product in the biotransformationfrom DIBOA to APO in these wheat crop soils and is consistent with previous findings. APO was notdegraded after three months in soil, suggesting that its degradation rate in soil is very slow.Keywords: Benzoxazinoids; DIBOA-Glc; DIBOA, BOA; biodegradations; soil; Triticum aestivum;bioactivity