[Objective] This paper was aimed to study the biological characteristics of Colletotrichum orbiculare（Berk.et Mont.） Arx, and accomplish the preliminary screening the test of fungicides. [Method]The pathogen was iso...[Objective] This paper was aimed to study the biological characteristics of Colletotrichum orbiculare（Berk.et Mont.） Arx, and accomplish the preliminary screening the test of fungicides. [Method]The pathogen was isolated from the infected leaves of watermelon collected from greenhouse in Hainan Province. The biological characteristics of C. orbiculare and indoor toxicity of fungicides were studied. [Results] The mycelium grew fastest on the medium with leaf extract of watermelon. The optimum temperature for mycelial growth and spore germination was 28 and 30 ℃, and the optimum pH was 7-9 and 6-8, respectively. The continuous darkness condition was most suitable for mycelial growth. The lethal temperature of spore was 55 ℃ water bath for 10 min in water bath. The suitable carbon sources were maltose, L-arabinose and glucose, and the suitable nitrogen sources were yeast extract, beef extract and peptone. In the indoor toxicity determination, 32.5% Benzoic azoxystrobin SC, 50% Dichlorotetrakis WP and 10% Difenoconazole WG showed better inhibition effects against the mycelial growth of C. orbiculare, with the EC50 values of 0.018 0, 0.060 2 and 0.471 5 μg/ml, respectively. [Conclusion]The research provided theoretical basis for the control of watermelon anthracnose in watermelon fields.展开更多
Dry heat treatment has been identifie as a method for disinfecting seed-borne pathogens in vegetable seeds. This study demonstrated that three seed-borne pathogens of cucumber(Cladosporium cucumerinum that causes scab...Dry heat treatment has been identifie as a method for disinfecting seed-borne pathogens in vegetable seeds. This study demonstrated that three seed-borne pathogens of cucumber(Cladosporium cucumerinum that causes scabs, Ascochyta citrullina that results in gummy stem blight,and Colletotrichum orbiculare that induces anthracnose) could be effectively eradicated from cucumber seeds by dry heat treatment. In vitro growth of these three pathogens was inhibited by dry heat treatment at 70 °C for 40 min. These pathogens were inactivated after exposing infected seeds to 70 °C dry heat for at least 90 min. Seed infection was significant y reduced by exposing the seeds to 70 °C dry heat for at least 40 min. Seed moisture content and germination were slightly reduced after 70 °C heat treatment for 40–120 min. Seed vigor remained at a high level after dry heat treatment at 70 °C for 90 min. In conclusion, 70 °C dry heat treatment for 90 min was determined to be the optimal method for eradication of C. cucumerinum, Didymella bryoniae, and C. orbiculare from cucumber seeds.展开更多
从连作多年的黄瓜根际土样中筛选得到1株对黄瓜炭疽病菌Colletotrichum orbiculare具有较强拮抗活性的菌株WF-3。通过菌落形态观察、生理生化特性及16S r DNA序列分析,该菌株鉴定为甲基营养型芽孢杆菌Bacillus methylotrophicus。活体...从连作多年的黄瓜根际土样中筛选得到1株对黄瓜炭疽病菌Colletotrichum orbiculare具有较强拮抗活性的菌株WF-3。通过菌落形态观察、生理生化特性及16S r DNA序列分析,该菌株鉴定为甲基营养型芽孢杆菌Bacillus methylotrophicus。活体盆栽条件下,该菌株对黄瓜炭疽病的防治效果为66.48%。两年的田间试验表明拮抗菌株WF-3培养物对黄瓜炭疽病具有良好的防治效果,防效分别为68.14%和73.70%。展开更多
基金Supported by Scientific Funds Project of Hainan Province[(QCY(2009)71]Local Standards of Hainan Province in 2011 "Technical Regulation of Greenhouse Watermelon Production"Project[QZJJ(2011)11]
文摘[Objective] This paper was aimed to study the biological characteristics of Colletotrichum orbiculare（Berk.et Mont.） Arx, and accomplish the preliminary screening the test of fungicides. [Method]The pathogen was isolated from the infected leaves of watermelon collected from greenhouse in Hainan Province. The biological characteristics of C. orbiculare and indoor toxicity of fungicides were studied. [Results] The mycelium grew fastest on the medium with leaf extract of watermelon. The optimum temperature for mycelial growth and spore germination was 28 and 30 ℃, and the optimum pH was 7-9 and 6-8, respectively. The continuous darkness condition was most suitable for mycelial growth. The lethal temperature of spore was 55 ℃ water bath for 10 min in water bath. The suitable carbon sources were maltose, L-arabinose and glucose, and the suitable nitrogen sources were yeast extract, beef extract and peptone. In the indoor toxicity determination, 32.5% Benzoic azoxystrobin SC, 50% Dichlorotetrakis WP and 10% Difenoconazole WG showed better inhibition effects against the mycelial growth of C. orbiculare, with the EC50 values of 0.018 0, 0.060 2 and 0.471 5 μg/ml, respectively. [Conclusion]The research provided theoretical basis for the control of watermelon anthracnose in watermelon fields.
基金supported by the earmarked fund for the Science and Technology Innovation Program of the Chinese Academy of Agricultural Science(CAAS-ASTIP-IVFCAAS)the National Key Technology Support Program(2012BAD19B06)funded by the Key Laboratory of Horticultural Crops Genetic Improvement,Ministry of Agriculture in China
文摘Dry heat treatment has been identifie as a method for disinfecting seed-borne pathogens in vegetable seeds. This study demonstrated that three seed-borne pathogens of cucumber(Cladosporium cucumerinum that causes scabs, Ascochyta citrullina that results in gummy stem blight,and Colletotrichum orbiculare that induces anthracnose) could be effectively eradicated from cucumber seeds by dry heat treatment. In vitro growth of these three pathogens was inhibited by dry heat treatment at 70 °C for 40 min. These pathogens were inactivated after exposing infected seeds to 70 °C dry heat for at least 90 min. Seed infection was significant y reduced by exposing the seeds to 70 °C dry heat for at least 40 min. Seed moisture content and germination were slightly reduced after 70 °C heat treatment for 40–120 min. Seed vigor remained at a high level after dry heat treatment at 70 °C for 90 min. In conclusion, 70 °C dry heat treatment for 90 min was determined to be the optimal method for eradication of C. cucumerinum, Didymella bryoniae, and C. orbiculare from cucumber seeds.
文摘为探究不同植物生长调节剂对杜鹃叶片生长和花期的影响,以长圆团叶杜鹃(Rhododendron orbiculare)为研究对象,在施用9种植物生长调节剂后的30 d和60 d,采用野外调查法测量叶片的长度、宽度等生长指标,使用英国皇家园艺学会比色卡(royal horticultural society color chart,RHSCC)和色差仪对叶片颜色指标进行测量,定期定点观察初花期。结果表明:胺新脂(DA-7)、复硝酚钠、吲哚丁酸钾、十三烷醇、四甲基戊二酸和6-苄氨基嘌呤(6-BA)可有效扩大成熟叶面积,且所有处理均能显著促进新梢伸长;在施用植物生长调节剂后,成熟叶片的RHSCC值和明度(L^(*))、红绿轴指数(a^(*))、黄蓝轴指数(b^(*))数值整体由偏黄向绿色转变。复硝酚钠综合效果最为突出,在第30天和第60天时的叶片生长速度均最快;在第60天时,成熟叶片长度和宽度分别较对照提高20.4%和19.6%,新梢长度增长125%;复硝酚钠处理组的成熟叶片RHSCC为NN137B,叶色描述为灰橄榄绿,L^(*)为37.07,b^(*)为15.06,为所有试验组中最低,绿色最深,其叶绿素含量最高;此外复硝酚钠表现出最强的促花性,初花期提前达10 d。复硝酚钠兼具叶片快速促生、显著增绿与调控初花期的多重优势,最适宜作为长圆团叶杜鹃叶面生长调节剂。
文摘从连作多年的黄瓜根际土样中筛选得到1株对黄瓜炭疽病菌Colletotrichum orbiculare具有较强拮抗活性的菌株WF-3。通过菌落形态观察、生理生化特性及16S r DNA序列分析,该菌株鉴定为甲基营养型芽孢杆菌Bacillus methylotrophicus。活体盆栽条件下,该菌株对黄瓜炭疽病的防治效果为66.48%。两年的田间试验表明拮抗菌株WF-3培养物对黄瓜炭疽病具有良好的防治效果,防效分别为68.14%和73.70%。
