【作者】 廖安平；

【导师】 叶华智；

【作者基本信息】 四川农业大学 ， 植物病理学， 2008， 硕士

【摘要】 川红花是四川地道中药材,红花锈病是危害叶片的主要病害,该病由红花柄锈菌[Puccinia carthami(Hutz)Corda]引起。本文较系统的对红花柄锈菌的生物学特性、侵染过程、侵染条件、初侵染源及和田间发生动态,以及品种抗性鉴定等方面进行了研究。一、红花柄锈菌[P.carthami(Hutz)Corda]的生物学特性研究了红花柄锈菌三种孢子:冬孢子、夏孢子、锈孢子萌发的温度、湿度、pH、光照、营养条件、存活力和致死温度等。冬孢子萌发的温度范围是5-30℃,最适温度25℃;pH7-8有利于萌发;相对湿度90%才开始萌发;在无菌水中的萌发率极低,加入10%的红花叶片汁液可以显著提高冬孢子的萌发率;冬孢子的致死温度为45℃(10min)或44℃(20min)。夏孢子萌发的温度范围是5-30℃,最适温度是25℃;pH为7最适宜萌发;在相对湿度90%中才能萌发;在RH100%+水滴萌发最好;夏孢子在无菌水中萌发最好;最适条件下,2h开始萌发,12h后萌发率达80%以上;光照对夏孢子的萌发无显著影响;夏孢子的致死温度是42℃(15min)或43℃(10min)。锈孢子萌发的温度范围是10-32℃,以25℃下萌发最好,12h后的萌发率可以高达95.5%。冬孢子不经休眠即可萌发,冬孢子、锈孢子、夏孢子的寿命较长,可分别存活约320d、140d、120d。二、红花柄锈菌[P.carthami(Hutz)Corda]的侵染过程红花柄锈菌的夏孢子在叶片表面接种12h后即可萌发产生芽管形成菌丝,菌丝形成附着孢通过表皮和气孔两种途径侵入寄主,以气孔侵入为主。菌丝在寄主叶肉细胞间隙蔓延。被侵染的叶肉细胞后期发生质壁分离,慢慢坏死。经过一定时间,菌丝在表皮下集结形成夏孢子堆,成熟后突破表皮,散出夏孢子。三、红花柄锈菌[P.carthami(Hutz)Corda]的侵染条件红花柄锈菌的冬孢子、锈孢子和夏孢子侵染和引起发病的温度范围均为10-28℃,23℃左右为最适温度,潜育期和孢子堆形成所需的时间最短。三种孢子的潜育期分别为12d、7d、8d。夏孢子在成长叶上比在幼嫩叶上更容易侵染并引起发病。最佳保湿时间为36—48h,潜育期约为8d。四、初侵染源及田间发生动态试验结果表明,混杂在土壤、病残体、种子表面的冬孢子都可作为初侵染源,足以引起红花发病。在四川雅安的环境下,田间病残体和种子及土壤中的冬孢子不经过越冬,在当年就直接侵染秋播的红花幼苗。播种后一个月就在田间幼苗上见到有红花锈病发生,在幼苗的茎和叶子上出现的斑点,然后在上面产生性孢子器和锈孢子堆及锈孢子。从11月到次年2月,随着温度的降低,病情发展缓慢。次年气温逐渐升高,病情开始发展并逐渐加重。病叶上形成的夏孢子随气流不断传播,进行重复侵染。病害从基部叶片向上部叶片及邻近植株扩散,以基部叶片受病最重。4月中旬,病情指数达到最高,随后逐渐发展缓慢。随着植株进入生长后期,夏孢子停止再侵染,叶片上出现冬孢子堆。冬孢子在下一个生长季节合适的条件下又继续侵染红花植株。五.品种抗性鉴定共鉴定了11份红花种质资源的抗病性,差异显著,其中有两个免疫品种,一个高感品种,其他的品种表现中抗或中感。这结果为抗病育种提供了一定依据。更多还原

【Abstract】 Safflower was a important medicinal plant caused by Puccinia carthami (Hutz)Corda.The safflower rust was the most destructive foliar disease of safflower. The biological characteristics and the infection of the pathogen were studied first and systematically.The results wrer as follows:1.The biological characteristics of the P.carthami(Hutz) CordaThe biological characteristics of three kinds of spores were studied mainly, including Teliospore,Urediniospore and Aeciospore.The temperature range for Yeliospore germination was 5 to 30℃,the optimum temperature was at 25℃.The most suitable pH value was 7-8.The lowest relative humidity of germination was 90%.The minimum rate of Teliospore germination was in water,and host juice stimulated Teliospore germination of the Teliospore markedly.The lethal temperature of Teliospore was 45℃.(10min)or 44℃.(20min).The optimum temperature of Uredospore germination was 25℃in the range from 5℃to 30℃.The optimum pH value for Uredospore germination was 7.The lowest relative humidity of germination was 90%and the maximum rate of Uredospore germination was in water.The percentage of Uredospore germination in water drop is higher than that in other nutrition.Germination of Uredospore started within 2 hours and the percentage of germination reached above 80%at 12 hours.The light hadn’t evident effect on Uredospore germination.The lethal temperature of Uredospore was 42℃(15min) or 43℃(10min).Aeciospore germinated at 10 to 32℃,with optimum temperature of 25℃,and the percentage of germination reached 95.5%at 12 hours.The Teliospore can germinate without dormancy.Teliospore,Urediniospore and Aeciospore may live as long as320d,140d and 120d.2.The infection process of P.carthami(Hutz)CordaInfection process to safflower by Puccinia carthami(Hutz)Corda was studied. Results showed that Uredospore germinated on the leaves surface,then formed the branched hypha,when hypha reached stomata,The appressorium was not formed clearly.The pathogen was able to penetrate host through two paths such as stomata and epidermis after inoculation.The direct penetration into stomata was considered as a major way.The mycelium spread in the leaf cells gap.The cells that were infected became empty.After a certain period,Mycelium formed a colony.The colony assembly under the epidermis formed Uredinium,which break through epidermis and spilled out uredospore after maturity.3.The infection conditions of P.carthami(Hutz)CordaThe infection of safflower by Teliospore,Urediniospore and Aeciospore could be occured at 10 to 28℃,the incubation period was the shortest and the optimum temperature of infection was about 23℃.The shortest incubation period of Teliospore was 12d.The incubation period of Urediniospore was the shortest(8d) at 23℃and the optimum temperature of infection was 20 to 23℃.The incubation period of Aeciospore was 7d at 23℃.The Urediniospore infected the basal leaves firstly,the spreaded to the upper leaves.Old leaves had more conducive to the infection.The optimum wetness period was 36-48hours and the incubation period was the shortest(8d).4.The infection sources and diesease dynamics of safflower in fieldSafflower rust can be caused by the teliospore which on the seed and the disease leaves and in the soil.Under Ya’an in Sichuan ecological conditions,the Teliospore which on the seed plants and the disease leaves in the field infected safflower seedlings directly without overwinter.The primary diseased plants could be observed one month later.The Teliospore infected cotyledon firstly,where appeared chlorosis spot and Aeciospore.From November to February of the following year,the disease developed slowly with chilliness.From February to April,the development of the disease accelerated gradually with the temperature rise.The Urediniospore on leaves spreaded by air and infected leaves as reinfection sources.The expansion of the disease from the lower leaves to upper leaves and nearby plant.At the end of April, the index of disease up to the highest,then the disease degree began to slow down gradually.With the cessation of safflower growth and the development of the disease stopped at the end of April.Urediniospore was replaced by Teliospore,which would infect host next season on the feasible condition.5.Resistance evaluation for safflower rustThe result shown that there were obvious difference among eleven tested varieties.Two varieties were immune to the disease;one variety was HS;others were MR or MS.The result is useful in breeding for disease resistance.更多还原