Prom Louis K, Isakeit Thomas, Odvody Gary N, Rush Charlie M, Kaufman Harold W, Montes Noe
USDA-ARS, Southern Plains Agriculture Research Center, 2765 F & B Road, College Station, TX 77845.
Department of Plant Pathology and Microbiology, Texas A&M University, College Station 77843.
Plant Dis. 2005 Jan;89(1):39-43. doi: 10.1094/PD-89-0039.
Survival of the sorghum ergot fungus, Claviceps africana, based on pathogenicity of recovered macroconidia used to inoculate sorghum (Sorghum bicolor), was measured in 2000 over the course of the year at five locations in Texas representing three climates. The experiment was repeated in 2001. Sphacelia associated with infected sorghum panicles were placed in nylon mesh bags and either buried at a 10-cm depth, placed on the soil surface, or suspended 61 cm above the ground. Samples were recovered after 4, 8, and 12 months and assessed for pathogenicity of surviving macroconidia by macerating tissue in water and spraying it onto panicles of flowering male-sterile sorghum in the greenhouse. Survival of ergot macroconidia in recovered panicles declined at all locations after the first 4 months that panicles were left in the field. The decline in viability during this period was greater in 2001 than in 2000. In 2000, survival after 4 months was greatest at Lubbock and Bushland, which have a continental steppe climate, than at the other three Texas locations, Weslaco and Corpus Christi, which have a subtropical subhumid climate, and College Station, which has a subtropical humid climate. However, this difference in survival was not as pronounced in 2001. Additionally, after 8 months, survival levels at all locations were similar. At the end of 12 months, infective macroconidia were found only at Lubbock in 2000, and only at Lubbock and College Station in 2001. Ergot macroconidia can survive in all major sorghum production areas of Texas; thus, conidia would not need to move long distances in order to initiate an epiphytotic.
2000年，在得克萨斯州代表三种气候的五个地点，基于用于接种高粱（双色高粱）的回收大分生孢子的致病性，对高粱麦角菌（非洲麦角菌）的存活情况进行了全年测量。该实验于2001年重复进行。将与受感染高粱穗相关的分生孢子座置于尼龙网袋中，要么埋于10厘米深处，要么置于土壤表面，要么悬挂于离地面61厘米高处。4、8和12个月后回收样本，并通过在水中浸软组织并将其喷洒到温室中开花雄性不育高粱的穗上来评估存活大分生孢子的致病性。在穗留在田间的前4个月后，所有地点回收穗中麦角大分生孢子的存活率均下降。2001年这一时期活力的下降幅度大于2000年。2000年，4个月后的存活率在具有大陆性草原气候的拉伯克和布什兰最高，高于得克萨斯州其他三个地点，即具有亚热带半湿润气候的韦斯拉科和科珀斯克里斯蒂，以及具有亚热带湿润气候的大学城。然而，2001年这种存活差异并不那么明显。此外，8个月后，所有地点的存活水平相似。在12个月末，2000年仅在拉伯克发现有感染性的大分生孢子，2001年仅在拉伯克和大学城发现。麦角大分生孢子能在得克萨斯州所有主要高粱产区存活；因此，分生孢子无需远距离传播就能引发流行病害。
