Abstract:
Anthracnose caused by various species of Colletotrichum is one of the most prevalent diseases in alfalfa worldwide that not only reduces forage yields but also severely compromises forage quality. A comprehensive survey was conducted in 2020 in the main production regions of northern China. The survey results showed that alfalfa anthracnose is prevalent in northern China, with the disease incidence ranging from 9% to 45% and the disease index from 5 to 17 (maximum possible score: 100). In total, 24 isolates were collected and identified as three Colletotrichum species (C. trifolii, C. truncatum and C. americae-borealis) based on morphological characteristics and phylogenetic analysis (combined sequences ITS, HIS3, ACT and GAPDH). The three species displayed remarkable environmental adaptability, exhibiting a capacity for growth, sporulation and conidial germination in temperatures ranging from 4 to 35 °C and in different nutrient conditions. Pathogenicity assays showed that C. trifolii was more virulent than the other two species, although the growth vigor (in terms of colony diameter, sporulation and conidial germination) of C. truncatum was the greatest.
摘要:
由各种炭疽病引起的炭疽病是全球苜蓿中最普遍的疾病之一,不仅降低了牧草的产量,而且严重损害了牧草的质量。2020年对中国北方主产区进行了全面调查。调查结果表明,苜蓿炭疽病在我国北方普遍存在,疾病发病率从9%到45%,疾病指数从5到17(最大可能得分为:100)。总的来说,收集了24个分离株,并鉴定为三种炭疽菌(C.trifolii,根据形态特征和系统发育分析(组合序列ITS,HIS3,ACT和GAPDH)。这三个物种表现出显著的环境适应性,表现出增长能力,在4至35°C的温度和不同的营养条件下,孢子形成和分生孢子萌发。致病性试验表明,三叶草比其他两个物种更具毒力,虽然生长活力(就菌落直径而言,刺梨的孢子形成和分生孢子萌发)最大。