Sweetpotato [Ipomoea batatas (L.) Lam.], is an important food crop worldwide. Weed management is consistently ranked among the top priorities of the sweetpotato industry in the United States (U.S.). Unfortunately, weed management of sweetpotato in the U.S. can be challenging as there are few herbicides labeled for use on the crop. Clomazone is one of the most widely used herbicides on sweetpotato in the U.S. and is effective in controlling several annual broadleaf weed and grass species and there is interest in developing germplasm that is tolerant to the herbicide. There is a lack of information concerning clomazone tolerance for sweetpotato plant introductions (PIs) that are contained within the germplasm collection of the USDA, ARS, Plant Genetic Resources Conservation Unit. The present study evaluated 564 sweetpotato PIs for tolerance to clomazone under a recommended rate in a field plot, with the objective of identifying sources of tolerance to clomazone. Clomazone injury ratings [1 = no chlorosis, 3 = minor chlorosis (< 20% leaf area), 7 = moderate chlorosis (20–50%), 9 = severe chlorosis (> 50%)] of the 564 sweetpotato PIs indicated that the majority (N = 497 PIs) had either no chlorosis or minor damage. There is ample phenotypic diversity for periderm (skin) and stele (flesh) color and dry matter present within the clomazone tolerant PIs. Additionally, there is sufficient genetic diversity present, as 108 PIs have been characterized and assigned to four genetic clusters with another 81 PIs having high levels of mixed ancestry. The results reported here provide critical baseline data for future studies of resistance and practical breeding for tolerance to clomazone.

甘薯[ Ipomoea batatas（L.）Lam。]，是全球重要的粮食作物。杂草处理一直被列为美国甘薯行业的重中之重。不幸的是，在美国，甘薯的杂草管理可能会面临挑战，因为很少有标有用于作物的除草剂。Clomazone是美国甘薯上使用最广泛的除草剂之一，可有效控制数种一年生阔叶杂草和草种，并且有兴趣开发能耐受该除草剂的种质。美国农业部，ARS，植物遗传资源保护单位的种质资源所包含的有关甜薯植物引种（PI）的广灭灵耐受性信息不足。本研究在田间试验中以推荐的速率评估了564个甘薯PI对clomazone的耐受性，目的是确定对clomazone的耐受性来源。564个甘薯PI的Clomazone伤害等级[1 =无萎黄，3 =轻微萎黄（<20％叶面积），7 =中度萎黄（20–50％），9 =严重萎黄（> 50％）]表明大多数（N = 497 PIs）没有萎黄或轻微损坏。在耐广灭灵的PIs中存在大量的表皮（皮肤）和石碑（果肉）颜色和干物质表型多样性。此外，存在足够的遗传多样性，因为已经鉴定了108个PI，并将其分配给四个遗传簇，另外81个PI具有高水平的混合血统。