Belz Regina G, Hurle Karl
Department of Weed Science, Institute for Phytomedicine 360, University of Hohenheim, 70593 Stuttgart, Germany.
J Chem Ecol. 2004 Jan;30(1):175-98. doi: 10.1023/b:joec.0000013190.72062.3d.
Crops that control weeds by root exudation of allelochemicals are receiving increased attention, and there are efforts to breed allelopathic cultivars in several crops. The genetic improvement of allelopathic traits is based upon parental germ plasm with high allelopathic activity. Identification of allelopathic germplasm is done in laboratory screening bioassays, but experimental protocols are limited. We developed a fast and reliable laboratory screening bioassay for grain crops that includes dose-response considerations as an integral part of the experimental design. The bioassay was conducted in hydroponic culture, and a range of experiments with 2-(3H)-benzoxazolinone (BOA), an allelochemical of several grain crops, was carried out to define the basic protocol. Because of its sensitivity to BOA, Sinapis alba L. was selected as the receiver species. BOA affected growth (fresh weight and length of shoot and root), enzyme activities (ascorbate peroxidase, catalase, glutathione S-transferase, peroxidase, phenylalanine ammonia-lyase), and chlorophyll fluorescence, whereby root length was the most reliable response parameter. BOA sensitivity was dependent on nutrients for all parameters measured, and, thus, no nutrients were added. A set of experiments with Secale cereale L. and Triticum aestivum L. as donor species was carried out to optimize the protocol. Light and pH were eliminated as primary causes for the observed inhibition. The proposed bioassay has several methodological advantages over current bioassays.
通过根系分泌化感物质来控制杂草的作物正受到越来越多的关注，目前人们正在努力培育几种作物的化感品种。化感性状的遗传改良基于具有高化感活性的亲本种质。化感种质的鉴定是在实验室筛选生物测定中进行的，但实验方案有限。我们开发了一种快速可靠的谷物作物实验室筛选生物测定方法，该方法将剂量反应考虑作为实验设计的一个组成部分。该生物测定在水培条件下进行，并对几种谷物作物的化感物质2-(3H)-苯并恶唑啉酮（BOA）进行了一系列实验，以确定基本方案。由于白芥对BOA敏感，因此选择白芥作为受体物种。BOA影响生长（地上部和根部的鲜重和长度）、酶活性（抗坏血酸过氧化物酶、过氧化氢酶、谷胱甘肽S-转移酶、过氧化物酶）和叶绿素荧光，其中根长是最可靠的反应参数。对于所有测量参数，BOA敏感性均取决于养分，因此未添加养分。以黑麦和普通小麦作为供体物种进行了一系列实验，以优化该方案。排除了光照和pH作为观察到的抑制作用的主要原因。与目前的生物测定方法相比，所提出的生物测定方法具有几个方法学上的优点。
