摘要
【目的】腐烂病菌(Valsa mali)在苹果树枝干木质部内生长扩展是导致剪锯口发病和旧病斑复发的重要原因,本研究旨在明确环境因子对腐烂病菌在枝干木质部内生长扩展的影响,为苹果腐烂病的流行预测和防控提供依据和参考。【方法】采用菌饼接种离体富士苹果枝条剪口后,用活体皮层检测病菌在枝条木质部内生长扩展距离的方法,研究温度、枝条相对含水量、枝条龄期、高温处理与浸水等因子对腐烂病菌在木质部内生长扩展的影响;采用菌饼接种离体、活体富士枝条剪口,系统监测腐烂病菌在枝条木质部内的周年生长扩展动态;通过离体培养,测试病菌在枝条不同组织配制培养基内的生长速度。【结果】腐烂病菌能够利用木质部内的水溶性养分生长扩展,病菌在木质部内的生长扩展速度显著快于在皮层内的生长速度;在5—35℃的范围内,腐烂病菌在苹果枝条木质部和皮层内都能生长扩展,最适温度为30℃;在浸水枝条木质部内,腐烂病菌的扩展距离显著短于未浸水枝条;当枝条的相对含水量大于90%时,腐烂病菌在木质部内的生长扩展速度较快,当枝条的含水量低于90%时,病菌的生长扩展受到明显的抑制;病菌在当年生枝条木质部内的生长扩展速度显著快于在2—3年生枝条木质部内的扩展速度;在经高温处理枝条木质部内,腐烂病菌的扩展速度显著快于未处理枝条;在用木质部粉末、韧皮部粉末、木质部浸出液、韧皮部浸出液制作的培养基中,腐烂病菌都能正常生长,其生长速度和生长量都不低于在PDA中的生长;腐烂病菌在韧皮部培养基中,气生菌丝多,在木质部培养基中气生菌丝少;自然条件下,接种到枝条剪锯口上病菌的生长扩展速度主要受温度的影响,12月至次年3月份,腐烂病菌在活体的富士枝条内扩展速度很慢,3—11月份扩展较快。【结论】腐烂病菌在木质部内可利用可溶性养分生长,其扩展速度显著快于在皮层内的扩展速度;腐烂病菌在木质部内的生长扩展速度受温度、枝条含水量、木质部的致密程度等因素的影响。
【Objective】The growth and extension of Valsa mali in the xylem of apple branches was an important cause of the occurrence of Valsa canker on pruning wounds and the recurrence of old lesions. The objective of this study is to determine the effect of environmental factors on the growth and extension of V. mali in the xylem of apple branches, and to provide the basis and reference for the epidemic prediction and control of the disease.【Method】By inoculating the pathogen to the pruning wounds of detached Fuji apple branches and detecting the extended distance of V. mali in the xylem with living bark, the effects of temperature, relative water content and age of branches on extension of the pathogen in the xylem of apple branch were tested. By inoculating the pathogen to the pruning wounds of Fuji apple branches in vitro and in vivo, the dynamics of annual growth of V. mali in the xylem was investigated systematically. Through in vitro culture, the growth rate of V. mali in medium made of different tissues of apple branch was surveyed.【Result】V. mali could grow and expand by using the water-soluble nutrients in xylem, and the extension rate of V. mali in the xylem was significantly faster than that in the cortex of apple branch. In the range of 5-35℃, V. mali could grow and expand in both xylem and cortex of apple branches, and the optimum temperature was 30℃. In the xylem of the branches soaked in the distilled water for 24 h, the spreading distance of V. mali was significantly shorter than that of un-soaked branches. When the relative water content of the branches was greater than 90%, the growth rate of V. mali in the xylem was faster. However, when the relative water content of the branch was less than 90%, the growth and extension of V. mali in the xylem was significantly inhibited. The extension rate of V. mali in the xylem of current year apple branch was significantly faster than that in the xylem of the two to three years branch. In the xylem of the branches treated with high temperature, the growth rate of V. mali was significantly faster than that of the untreated branches. V. mali could grow normally in the medium made of xylem powder, phloem powder, xylem extract and phloem extract of apple branches, and its growth rate and growth amount were not lower than those in PDA. The number of aerial mycelia in phloem medium was more than that in xylem medium. Under natural conditions, the growth and extension rate of V. mali inoculated on pruning wound was mainly affected by temperature. The growth rate of V. mali in vivo Fuji branches was very slow from December to March and relatively fast from March to November. 【Conclusion】 V. mali can grow by using the water-soluble nutrients in the xylem, and the growth rate in the xylem was significantly faster than that in the cortex of apple branch. The growth rate of V. mali in xylem is mainly affected by temperature, water content of branches, density of xylem and so on.
作者
王晓焕
潘彤彤
练森
王彩霞
李保华
WANG XiaoHuan, PAN TongTong, LIAN Sen, WANG CaiXia, LI BaoHua(College of Plant Health and Medicine, Qingdao Agricultural University/Key Lab of Integrated Crop Pest Management of Shandong Province, Qingdao 266109, Shandon)
出处
《中国农业科学》
CAS
CSCD
北大核心
2018年第17期3291-3301,共11页
Scientia Agricultura Sinica
基金
国家自然科学基金(31371883)
国家苹果产业技术体系(CARS-28
CARS-27)
国家重点研发计划(2016YFD0201122)
山东省重点研发计划(2017CXGC0214)
