【作者】 祝军；

【导师】 孔祥清；

【作者基本信息】 黑龙江八一农垦大学 ， 植物病理学， 2009， 硕士

【摘要】 小蓟(Cephalanoplos segetum)是我国农田的主要的恶性杂草之一,发生十分广泛。主要依靠人工除草和化学除草剂防除,大量化学农药的使用也是无公害生产的主要障碍。植物病原物成为消除杂草危害的一种新方法。本试验从野外发病植物小蓟上得到4种致病菌,筛选出致病力最强且对作物安全的一种菌株,初步鉴定属于链格孢属。对该链格孢菌生物学特性进行了系统研究,包括不同培养条件(温度、光照、PH、通气等)研究,明确了菌落生长及产孢的最适宜条件。通过链格孢菌对温室盆栽小蓟致病力测定,室内初步明确了应用链格孢菌防治小蓟的防治效果,为田间应用提供了理论依据。结果如下:1.菌株LD-2生长情况较好,产孢量较大,防治效果显著,感病率达到了40%,而且对作物安全。2.在10×10倍OLYMPUS数码显微镜下观察乳酚油玻片,观察到分生孢子梗单生或数根簇生直立或弯曲,分隔多分枝,淡褐色至褐色,41.9~68.4×3.5~4.5μm;分生孢子单生或短链生,倒棍棒形,卵形,倒梨形或近椭圆形,淡褐色至褐色,具3~8个横隔膜和1~4个纵隔膜,分隔处不溢缩或略溢缩,孢身18.4~30.1×7.5~10.7μm;短喙柱状或锥形,淡褐色,8.0~17.7×2.5~3.2μm。鉴定为链格孢(Alternaria alternata)。3.菌株在25℃时菌丝生长最快,产孢量最大。在PDA培养基上生长最快,产孢量最大;以葡萄糖为碳源,硝酸钠为氮源的培养基上光暗交替条件下生长情况最好;蔗糖为碳源,硝酸钠为氮源的培养基上在无光照条件下,病原菌产孢最多。4.菌株LD-2在温度25~28℃、相对湿度(RH)95%以上、接种液孢子浓度5.0×106个/mL时,对小蓟的防治效果最好;菌株LD-2对1.0~3.0叶期的小蓟感病率最高,3.0叶期以后防治效果明显下降;光照条件对菌株的防治效果没有太大影响。更多还原

【Abstract】 Thistle is one of the major weeds in farmland,occur to a wide range of nature. It mainly rely on manual weeding and chemical herbicides control,use of a large number of chemical pesticides is a major obstacle to pollution-free production. Plant pathogen become a new way to the eliminate weeds. Four kinds of pathogens were found in wild inoculated thistle,then selected the most pathogenic strain on crop safety. Preliminary identification,it belong to Alternaria. Through alternaria on the system of biological characteristics,mainly including the research of different culture conditions (temperature,light, PH,ventilation,etc.), the colony growth and sporulation conditions for the most appropriate was made clear. Through the virulence test of Alternaria to potted thistle,Application of the initial clear control of Alternaria alternata’s effect of greenhouse,and evaluation,Further to applicate to field a theoretical basis for the special.The results show that:1.Mycelial growth of LD-2 strain is more faster,sporulation is larger, bio-control is significant,Rate of influenza illness by 40%,and the safety of crops.2. 10×10 times in the digital microscope OLYMPUS milk glass oil phenols observed conidial stalk with solitary or clustered or vertical bending, multi-separated branches,light brown to brown, 41.9~68.4×3.5~4.5μm,Conidia single,or short-chain,was a stick-shaped,oval,inverted pear-shaped or nearly oval-shaped, light brown to brown,with 3 to 8 diaphragm and 1 to 4 vertical septum,separated to non-overflow or slightly overflow,spore body 18.4~30.1×7.5~10.7μm. Cylindrical or cone-shaped,light brown,8.0~17.7×2.5~3.2μm. Identified as Alternaria(Alternaria alternata).3.Strains at 25℃fastest mycelial growth,conidiation largest. PDA growth medium in the fastest, largest conidiation:under the conditons of glucose as nitrogen source,nitrate as nitrogen source of medium , alternating light and dark fastest mycelial growth:sucrose as carbon source, sodium nitrate as nitrogen source medium in the whole of the dark conditions, the pathogen most conidiation.4.Strain LD-2 at temperature of 25 ~ 28℃, relative humidity(RH)95% and more vaccinated solution concentration 5.0×10~6 / mL,the effect of the best to thistle:Strain LD-2 for 1.0 ~ 3.0 leaf period the highest rate of influenza percentage,after 3.0 leaf stage control effect decreased significantly:Different illumination conditions on the strain has little impact.更多还原