福建黄果西番莲果腐病菌分离鉴定及其生物学特性

为探究引起福建黄果西番莲采后果腐病的病原菌及其生物学特性,组织分离病果病原菌,采用柯赫氏法验证其致病性,观察病菌形态特征,结合分子生物学鉴定,采用同源性分析与系统发育树构建鉴定病原菌,并初步研究不同温度、pH值、碳源、氮源等对病原菌菌落生长的影响。结果表明,根据形态学和分子生物学鉴定,引起福建黄果西番莲采后果腐病的病原菌为可可毛色二孢Lasiodiplodia theobromae,28℃、pH值6、葡萄糖、硝酸钾分别是L.theobromae菌落生长最适温度、pH值、碳源和氮源。

百香果采后果腐病菌的生物学特性及其杀菌剂毒力测定

可可毛色二孢Lasiodiplodia theobromae引起的果腐病是近年百香果果实新病害。为明确该病原菌的生物学特性,采用生长速率法测定了不同培养温度、pH值、碳源、氮源和光照对其菌丝生长的影响,并测定了14种杀菌剂对该病原菌的室内毒力。结果表明,该病原菌最适生长pH值为4.5~5.5,最适生长温度为31~34℃;其可利用蔗糖等供试11种碳源,可利用硫酸铵等供试11种氮源,尿素为最难利用的氮源;不同光照条件对其菌丝生长的影响差异不显著。供试14种杀菌剂对病原菌菌丝生长均具有一定的抑制作用,其中,戊唑醇和丙环唑的毒力较高,其EC_(50)分别为0.0072和0.7067 mg/L,EC_(95)分别为90.5459和33.1295 mg/L。

Pathogen Identification of Stem Rot in Dendrobium officinale of China

For the control of stem rot in Dendrobium officinale, symptoms were observed and the pathogen was isolated and identified from April 2013 to August 2015. The pathogen only infected the stem of D. officinale, resulting in death of stem above the lesion. Strain TP-1 accounted for 65.7% of isolated colonies. After inoculation of TP-1 for 14 d, water-soaked necrotic lesions about 3 mm in diameter were observed, which were similar to natural infections, and the original strain was obtained after re-isolation. Morphology and sequencing identification confirmed that TP-1 was Lasiodiplodia theobromae. This is the first report of stem rot in D. officinale caused by L. theobromae in China.

菠萝蜜黑腐病病原菌的形态学与分子鉴定

为明确菠萝蜜黑腐病的病原菌和分类地位,本研究从海南保亭地区采样,经过田间调查、菌株分离纯化和致病性鉴定,以形态学特征为基础,结合病原菌的ITS序列和EF1-α序列,联合两基因建立系统发育树,最终鉴定该病害的病原。结果显示:病原菌LTHD006菌丝生长速度快,初期白色絮状,较薄,后期菌丝开始变黑,菌落也开始致密,且与Lasiodiplodia theobromae(ID:CBS175.26)聚为一个分支,支持率为100%,最终将菠萝蜜黑腐病的病原菌鉴定为可可毛色二孢(Lasiodiplodia theobromae)。该病害在国内为首次简略报道,研究结果为菠萝蜜黑腐病发病规律和防治的进一步研究提供理论基础。