Dep. of Plant Biology, Rutgers Univ., New Brunswick, NJ, 08901, USA.
Dep. of Agricultural Biology, Colorado State Univ., Fort Collins, CO, 80523, USA.
J Environ Qual. 2020 Mar;49(2):368-377. doi: 10.1002/jeq2.20038. Epub 2020 Mar 4.
Sorgoleone-358 is an important allelochemical of the oily droplets exuded from root hairs of various species in the Sorghum genus. Due to its hydrophobic nature, sorgoleone-358 can be strongly adsorbed onto soil organic matter, resulting in increased sorgoleone soil persistence. Because of the herbicidal activity of sorgoleone on many small-seeded weeds, concerns have been raised that sorghum residues may have a detrimental effect on emergence of wheat used as a double crop in the southeastern United States. Laboratory experiments were conducted to evaluate root exudate production and its sorgoleone-358 content for 36 cultivated sorghum cultivars as well as eight shattercane [Sorghum bicolor (L.) Moench ssp. arundinaceum (Desv.) de Wet & Harlan] accessions and one johnsongrass [S. halepense (L.) Pers.] accession. Using a capillary growing mat system, root exudate was extracted with dichloromethane and subjected to chromatography analysis to determine sorgoleone-358 content. Root biomass of 7- to 12-d-old seedlings averaged 18.8 mg g seed, and root exudate production ranged from 0.2 and 4.8 mg g root fresh weight (RFW). The amount of sorgoleone produced varied greatly among sorghum accessions. Sorgoleone-358 amount in the root exudate averaged 0.5 mg g RFW and varied from 0.13 to 1.05 mg g for shattercane cultivar S7 and cultivated sorghum cultivar 992123, respectively. Regarding volume of root biomass, sorgoleone-358 levels averaged 0.49 mg g (range, 0.06-1.46 mg g ) for sorghum cultivar AAS3479 and shattercane cultivar S2, respectively. Segregation of commercial sorghum cultivars according to their maturity group did not show any difference in root biomass and dry extract production, but early-maturing cultivars produced on average 18% less sorgoleone-358 compared with medium- and late-maturing cultivars. These results suggest that sorgoleone production may be genetically constitutive because sorghum growing conditions were identical across cultivars.
Sorgoleone-358 是高粱属各种物种根毛分泌的油滴中的一种重要化感物质。由于其疏水性， sorgoleone-358 可以被强烈吸附到土壤有机质上，从而增加 sorgoleone 在土壤中的持久性。由于 sorgoleone 对许多小粒杂草具有除草活性，人们担心在美国东南部作为双季作物种植的高粱残留可能对小麦的出苗产生不利影响。进行了实验室实验，以评估 36 个栽培高粱品种以及 8 个碎米高粱[ Sorghum bicolor (L.) Moench ssp. arundinaceum (Desv.) de Wet & Harlan] 材料和 1 个约翰逊草[Sorghum halepense (L.) Pers.]材料的根分泌物产生及其 sorgoleone-358 含量。使用毛细管生长垫系统，用二氯甲烷提取根分泌物，并进行色谱分析以确定 sorgoleone-358 含量。7 至 12 天大的幼苗的根生物量平均为 18.8mg g 种子，根分泌物产量范围为 0.2 和 4.8mg g 根鲜重 (RFW)。高粱品种间产生的 sorgoleone 量差异很大。根分泌物中 sorgoleone-358 的平均含量为 0.5mg g RFW，碎米高粱品种 S7 和栽培高粱品种 992123 分别为 0.13 和 1.05mg g。关于根生物量的体积，高粱品种 AAS3479 和碎米高粱品种 S2 的 sorgoleone-358 水平平均分别为 0.49mg g（范围为 0.06-1.46mg g）。根据成熟组对商业高粱品种进行分类，根生物量和干提取物产量没有差异，但与中晚熟品种相比，早熟品种的 sorgoleone-358 平均减少 18%。这些结果表明，sorgoleone 的产生可能是遗传组成的，因为不同品种的高粱生长条件是相同的。
