Viral disease is one of the infectious diseases of fruit trees, infected with the virus of fruit trees are usually full of poison, lifelong victims, coupled with the current lack of effective control agents and measures, making it difficult to control once the epidemic of fruit tree virus disease.
Citrus yellowing pulse disease is a new occurrence of citrus virus disease at home and abroad, there may be many fruit farmers who do not understand the disease, for this reason the author has collected some pictures and information, now share with you.
Citrus yellowing pulse disease virus mitochondria under electron microscopy Image source: Niu Bingshu
In 1988, symptoms such as yellowing of leaf veins and transparent veins were observed on lemons and limes in Pakistan.
In 1993, citrus yellowing was first reported in Pakistan.
In 1996, grimaldi and catara observed a fibrovirus mitochondrial on lemon leaves showing symptoms of xanthraki, as shown above.
In the following period, the disease was also reported in India, Turkey and other places.
The disease was first detected in China in 2009 when huanglongbing disease was investigated, and it is currently occurring in the main citrus producing areas such as Yunnan, Sichuan, Hunan, Jiangxi, Guizhou, Hubei, Guangxi, Guangdong, Zhejiang, Chongqing, Guangzhou and Fujian.
It can infect most citrus plants such as lemon, lime, citron, grapefruit, sweet orange, lime, sugar orange, etc., of which lemons and limes are the most seriously harmful.
In addition to citrus, the disease can also harm herbs such as peppers, cowpeas, beans and quinoa.
Lemon victim symptoms (from left to right, spring, summer and autumn) Image source: Jin Xin, the same below.
Symptoms of grapefruit victimization (spring shoots, summer shoots, and autumn shoots from left to right)
Symptoms of sweet orange victimization (spring shoots, summer shoots, autumn shoots from left to right)
Symptoms of sugar orange victimization (old leaves and new leaves from left to right) Image source: Pu Jin'an
Typical symptoms Of the leaf veins Are bright Image source: Eunamo
Hazard characteristics:
(1) The epiphyte of the leaf is obvious, which is manifested by transparent yellowing of the leaf veins, and the later leaf wrinkles and deformities.
(2) Different varieties and different degrees of victimization. For example, the spring shoots of Wenzhou mandarin orange and Zhenxi grapefruit are often accompanied by fading green, flowers and leaves after feeling sick.
(3) There are differences between new leaves and old leaves, such as the curly leaves of sugar oranges and the pulse of new leaves.
(4) The symptoms of yellowing will be weakened after the leaves are mature, but the symptoms of leaf shrinkage will not recover.
(5) The degree of occurrence of the disease is affected by temperature, and the symptoms will be slightly alleviated at high temperatures, so the symptoms of spring and autumn are more obvious than those of summer.
(6) Citrus fruits are generally not characterized, but some varieties such as Wenzhou mandarin orange can have juvenile fruit deformity and fruit surface depression.
Although 80% of plant viral diseases rely on vector insect transmission, no insects have been found that mediate the spread of the virus between citrus. Vector insects such as meadowsweets and aphids can only be transmitted from diseased citrus crops to legumes, etc., and cannot be transmitted among citrus.
However, once the disease occurs, it is reported to spread rapidly in a short period of time, so most scholars believe that there is some insect mediator that spreads the disease.
The main mode of transmission of the disease is grafted transmission, and the transmission efficiency is high. Seedlings can be transmitted over long distances, and although the virus can be detected in seed tissue, the disease cannot be transmitted through seeds.
(1) Strengthen the management of seedlings, use non-toxic seedlings, and prevent the disease from spreading over long distances with scion, rootstock or seedling transportation.
(2) Frequent inspection of the garden, the symptoms of spring shoots are obvious, which can be used as the main basis for judgment, and it is recommended that suspected diseased trees be inaccurate and sent for examination.
(3) Do not use branches of unknown origin for grafting, and agricultural tools such as grafting knives and branches and scissors must be disinfected to avoid cross-infection in the field.
(4) Although poisoning insects have not yet been found, the prevention and control of important suspected poisoning insects such as aphids, pest mites and whiteflies should be strengthened.
(5) Discover the disease and remove the diseased tree in time to avoid the spread of the disease.
bibliography: Molecular Detection and Biological Research of Citrus Yellowing Pulse Ming Virus, Cheng Qiao "Effects of Citrus Pulse Ming Virus Infection on Lemon Gene and Small RNA Expression" Niu Bingshu Genetic Diversity and Population Variation of Citrus Yellowing Pulse Ming Virus, Liu Huifang "Preliminary Investigation of Citrus Yellowing Pulse Ming Virus Insect Vector" Liu Cuihua "Study on the Effect of Citrus Yellowing Pulse Ming Virus on Chlorophyll Metabolism of Lemon, Grapefruit and Sweet Orange" Jin Xin
#谷丰计划 #
This article comes from the agricultural assistant, please indicate when reprinting, and do not modify the content of the article, the modification must be investigated! This article is the 131st in the series of "Making Agricultural Technology Simpler, Making Popular Science More Popular".