Identification, significance and transmission of seed borne. Seed borne inoculum therefore, has severe implications for yield, seed production and distribution systems, trade, human nutrition and germplasm. Park 1937 reported the beneficial effect of seed treatment against sclerotium rolfsii. Seed treatments control soil borne pathogens root rots, dampingoff, seedling blights control surfaceborne pathogens safflower rust control internallyborne pathogens loose smut fungi of cereals. Plp 6404 epidemiology of plant diseases spring 2015 lecture 5. Several pathogens which cause important diseases in chickpea, faba bean, pea, and lentil are seed borne and seed transmitted. Seed treatment to eliminate seedborne bacterial pathogens seed water temperature minutes f c brussels sprouts, eggplant, spinach, cabbage, tomato 122 50 25 broccoli, cauliflower, carrot, collard, kale, kohlrabi, rutabaga, turnip 122 50 20 mustard, cress, radish 122 50 15 pepper 125 51 30 lettuce, celery, celeriac 118 47 30 hot water treatment. Fungi, bacteria, viruses, nematodes, mycoplasmas and spiroplasmas host susceptiblecrop. For some plant diseases, seedborne inoculum is the only or principal source of infection. There is a serious scientific concern about the transmission of plant viruses sexually through seed and asexually through plant propagules. Pdf plant pathogens present a serious threat to seedling establishment and the potential for plant disease epidemics under greenhouse. It is well known that seed borne plant pathogens can cause disease or death of plants, resulting in crop and economic losses. Management of residueborne diseases of winter wheat. I am delighted to write the foreword for a book on seedborne viruses, since many economically important viral diseases are spread in nature through seeds.
Plant health solutions, 20 beauchamp road, warwick, cv34 5nu, uk. Many plant pathogens are seedborne, and their association with seed is an important means of dissemination and carryover between. Seed borne pathogens causes diseases at various stages of crop growth from germination of seed up to crop maturity and heavy losses have been observed, caused by seed borne pathogen in various crops. Seedborne fungi in 69 sunflower cultivars were evaluated which comprised 52 confectionery and 17 oilseed types. Seed quality and seed borne diseases of cereal crops seed generally refers to grain intended for planting, while grain is the term for sale into the marketplace as food, feed or fuel. Diseases caused by seedborne bacterial pathogens include black rot of crucifers, bacterial leaf spot of pepper, and bacterial canker of tomato. Feb 17, 2015 the seed borne pathogens may result in i loss in germination ii discoloration and shriveling iiidevelopment of plant diseases ivdistribution of pathogen to new areas v introduction of new strains or physiologic races of the pathogen along with new germplasm from other countries vitoxin production in infected seed etc. Systemic infection from roots or seed du toit et al. Seedborne pathogens and strategies to eliminate and. Seeds provide the primary inoculum from which many.
Control of cereal seedborne diseases by hot humid air seed treatment. Seed quality and seedborne diseases of cereal crops. Seed rhizomes have to be treated before planting to control rhizome rot and other seed borne diseases. Soilborne plant pathogens can be controlled by biological methods. The causes of transmitted plant diseases include the viruses, mycoplasmalike organ isms mlo, rickettsialike organisms rlo, the bacteria and the fungi. Seed rhizomes have to be treated before planting to control rhizome rot and other seedborne diseases. Seed borne diseases the establishment of a pathogen in, on and with the seed implies that the pathogen is seed borne. Ariena van bruggen emerging pathogens institute and plant pathology department, ifas university of florida. Definition and history of plant pathology important plant pathogenic organisms different groups fungi, bacteria, fastidious vesicular bacteria, phytoplasmas, spiroplasmas, viruses. Overview types of seedborne plant pathogens types of seedborne. Diagnostic assays based on pcr have been developed for major seed borne diseases of wheat. Control of cereal seedborne diseases by hot humid air seed.
Pdf effect of seed borne pathogens on germination of. Fraedrich introduction seeds are regarded as a highly effective means for transporting plant pathogens over long distances. Information about the population genetics of pathogens has been useful for the advancement of epidemiological investigations. Pathogens include fungi, bacteria, nematodes, and viruses, all biological organisms that can cause disease symptoms and significantly reduce the productivity, quality, and even cause the death of plants. Seed treatments control soil borne pathogens root rots, dampingoff, seedling blights control surfaceborne pathogens safflower rust control internallyborne pathogens. Organisms that cause infectious disease include fungi, oomycetes, bacteria. Seedborne pathogens can prevent germination and cause serious threats to seedling establishment valkonen and koponen, 1990. Seed diseases and seedborne pathogens of north america. Seeds and propagules infected by fungal pathogens constitute important primary sources of infection. The present book provides the latest information along with the total list of seed transmitted virus and viroid diseases at global level including, the yield losses, diagnostic techniques, mechanism of seed. Control of cereal seedborne diseases by hot humid air. Residueborne pathogens causing root and crown rots, seedling blights, and seedtransmitted foliar diseases can be managed by applying fungicide seed treatments table iii. Seed quality and seedborne diseases of cereal crops seed generally refers to grain intended for planting, while grain is the term for sale into the marketplace as food, feed or fuel. We speculated that seed association with this pathogen, in particular, originated from aerial deposition on developing cones.
Quality has different meanings, depending on whether it is grain being characterized for sale as. Chemical treatments of seed may be effective in controlling plant pathogens in, on, and around planted seed. Likelihood that a particular batch of seed could benefit from hot water treatment depends on the crop, the pathogens affecting it, and the seeds history. Pdf management of seed borne fungal diseases of tomato. Cooperative interactions between seedborne bacterial and air. Jan 19, 2017 information about the population genetics of pathogens has been useful for the advancement of epidemiological investigations. Eradication of seedborne plant pathogens plant health solutions. Detection, presence and control of seedborne pests and diseases. Knowledge of the biology of seedborne pathogens and practices for their management and control can help seed orchard and nursery managers reduce seed and seedling losses. Fungicide treatments to control seedborne fungi of. Seed treatment is therapeutic when it kills bacteria or fungi that infect embryos, cotyledons, or endosperms under the seed coat. Seedborne pathogens and strategies to eliminate and reduce.
A variety of fungicides can control residue borne wheat diseases. The management of these pathogens during the seed borne phase is considered to be the cheapest disease control strategy shenge, 2007. Seed sanitizing treatments can be used to prevent seed borne plant diseases, especially those caused by bacteria, and can minimize the potential risks associated with seed contaminated with foodborne pathogens. Quality has different meanings, depending on whether it is grain being characterized for sale as food, feed or fuel, or for use as seed to plant. Numerous examples exist in agricultural literature for the international spread of plant diseases as a result. Treatment of vegetable seeds has been shown to prevent plant disease epidemics caused by seedborne fungal pathogens. Seed borne pathogens causes seed and seedling rots, i. Fungicide treatments to control seedborne fungi of sunflower. Farmers using poorquality seed risk poor germination and the ultimate crop stand in their fields will be poor. Soilborne diseases and how to effectively treat them.
The management of these pathogens during the seedborne phase is considered to be. Plant pathology also phytopathology is the scientific study of diseases in plants caused by pathogens infectious organisms and environmental conditions physiological factors. Soil borne diseases will continue to frustrate backyard gardeners. Hot water treatment is one of the widely used methods to control seed borne pathogens but due to the hard hull of sunflower seeds, it has not been effective. Seed and plant parts pathogens survive in infected. Seedborne diseases an overview sciencedirect topics. Seed borne fungi in rice seed and their control under laboratory and field conditions in west bengal. Diagrams showing how pathogens can get inside seed plus additional useful information about seedborne pathogens are in a pdf file prepared by lindsey du toit.
Seed treatment induces early germination and prevents seed borne pathogens and pests. Cooperative interactions between seedborne bacterial and. Seed borne pathogens of vegetable and flower seeds. In view of the seed borne pathogens, causing substantial damage and to study the different aspects of the fungal pathogens and their effects on seed the following objectives were. Below are seedborne diseases of pulse crops, and economic their causal agents importance. Identification, significance and transmission of seed. Pdf the epidemiology and management of seedborne bacterial. Control of cereal seed borne diseases by hot humid air seed treatment. Contaminated seed can be an important first source of a pathogen on a farm or even a larger area most notable example is the new downy mildew of basil in the us. Rapid development of genomic techniques for characterization of plant pathogens of the past decades has.
Issn 14016249, isbn 915766496x treatment of cereal seed using hot, humid air, or aerated steam, was investigated as a method for control of seed borne diseases. Semiselective media used to detect various plant pathogenic bacteria advertisement. Seed borne pathogens on farmersaved sorghum sorghum. Seeds are attached by various stages, the mother plant get infected by the pathogen, it attack seed also. Information on the biology of microbial pathogens, including genetic diversity, infection process and survival mechanisms of pathogens and epidemiology of diseases caused by them, are.
Seed chain managing seedborne bacterial diseases reduce or eliminate bacterial diseases from seed production fields zero tolerance in seed production ring rot potato bacterial spot, speck and canker rigorous scouting cultural practices sanitized seed, crop rotation, protected culture, strict sanitation test seed for known high impact pathogens. Seeds are attached by various fungi, bacteria and virus. A variety of fungicides can control residueborne wheat diseases. Management seed producer plant pathogen free seed in seed production field indexed for pathogen culture, visual, elisa, pcr amount of seed tested determined by allowable threshold need better research hot water treatment fungicide treatment other treatmentessential oils, biologicals. Emerging microbial biocontrol strategies for plant pathogens. The regional pulse cropdiagnostic laboratory rpcdl test your seed lots for the presence of these pathogens. The highest percent germination was recorded in cucumber 87%, while the lowest in okra 49. Apart from other crops vegetables are also subjected to several seed borne fungal, bacterial and viral pathogens, which cause substantial yield loss upto 10 percent in pakistan. Pathogen characteristics that influence epidemic development. Organisms that cause infectious disease include fungi, oomycetes, bacteria, viruses, viroids, virus like organisms, phytoplasmas, protozoa, nematodes and. Important seedborne diseases of pulse crops aster yellows. Many plant pathogens can be seedborne, in particular downy mildews, smuts, fungi imperfecti that form pycnidia or acervuli, bacteria, viruses, and some nematodes maude, 1996. Planting vegetable varieties with resistance to common diseases can help to both limit the occurrence of problems and the spread of soil borne pathogens. Hot water treatment is one of the widely used methods to control seedborne pathogens but due to the hard hull of sunflower seeds, it has not been effective.
Detection and management in seeds and propagules provides a comprehensive resource on seedborne and propaguleborne pathogens. Seed borne pathogens on farmersaved sorghum sorghum bicolor. Many diseases are introduced in new areas via infected seed. Seed coats were placed on both np10 nonylphenol ethoxylate based surfacant. Important seedborne diseases of pulse crops below are. Seed borne diseasespathogens can be spread from the. The seed borne pathogens may result in i loss in germination ii discoloration and shriveling iiidevelopment of plant diseases ivdistribution of pathogen to new areas v introduction of new strains or physiologic races of the. Plant diseases may be found in, on or with seed and seed lots. Seed borne fungi in 69 sunflower cultivars were evaluated which comprised 52 confectionery and 17 oilseed types. Influence of pathogen on disease development seed borne pathogens epi prof. Walcott, 2003 and plant vigour anjorin and mohammed, 2014.
Littke and browning 1990 reported that orchard seed can be associated with seed borne pathogens such as fusarium oxysporum as well as other pathogens. Acceptance of a predefined level of a pathogen in a sample of a certain size is a typical feature of a quality disease. Planting diseasefree seeds is a smart way to minimize the possibility of the diseases and losses associated with them. Flooding is another method used to control seed borne pathogens like fusarium spp. Pdf seed treatments to control seedborne fungal pathogens of. Seed borne pathogens can prevent germination and cause serious threats to seedling establishment valkonen and koponen, 1990. Interactions between bacteria and fungi are common and contribute to ecosystem processes. Seedborne pathogens and strategies to eliminate and reduce their presence on tree seeds stephen w. Molecular diagnostics began to develop a real momentum after the introduction of pcr in the mid 1980s. Seed sanitizing treatments can be used to prevent seedborne plant diseases, especially those caused by bacteria, and can minimize the potential risks associated with seed contaminated with foodborne pathogens. Flooding is another method used to control seedborne pathogens like fusarium spp. Top 5 control methods against seed borne pathogens plant.
Growers are advised to test their seed lots and only plant. It reduces the viability of seeds and the seed borne pathogens are the most disastrous as they reduce the seed vigour and weaken the plant at the initial growth. Eradication of seedborne plant pathogens roberts sj. Introduction foresttree seed diseases and diseases related to seedborne pathogens are primarily caused by fungi. The role of seeds in the dissemination of plant diseases is well established. Bacterial pathogens borne in true seed crop pathogen s tomato pepper pseudomonas syringae pv. It is well known that seedborne plant pathogens can cause disease or death of plants, resulting in crop and economic losses. Residue borne pathogens causing root and crown rots, seedling blights, and seed transmitted foliar diseases can be managed by applying fungicide seed treatments table iii. Sheppard abstract recognition of the importance of seed borne diseases in vegetable and flower seeds is often overlooked, particularly in the case of flower seeds.
The disease can reduce seed yield and seed quality. Seed treatment induces early germination and prevents seedborne pathogens and pests. Maximum germination failure was recorded in okra 50. Vegetable seed sanitation louisiana state university. However, not every fungus causes plant problems and while the vast majority do not, over 8,000 fungi species do. The rate of contamination among the different varieties was calculated by counting seed coats with fungal colonies. It is a persistent issue worldwide that an enormous number of plant pathogens, varying from the smallest viroid consisting solely of a single strand of rna, to more complex pathogens such as viruses, bacteria, fungi, oomycetes and nematodes, cause many important plant diseases and are responsible for major crop losses. Soil borne inoculum alternaria radicina 8 years infected adjacent or overwintering crops or related weed hosts x. Alternative inoculum sources for seed borne carrot diseases infested residues alternaria dauciin ca gilbertson et al. Issn 14016249, isbn 915766496x treatment of cereal seed using hot, humid air, or aerated steam, was investigated as a method for control of seedborne diseases. There is a serious scientific concern about the transmission of plant viruses sexually. Epidemiology of plant diseases spring 2015 ariena van bruggen lecture 5. Dynamics of seedborne rice endophytes on early plant growth stages. Seeds provide an efficient means in disseminating plant virus and viroid diseases.
The success of modern agriculture depends on pathogen free seed with high yielding character and in turn disease management. Examples are given to illustrate the importance of contaminated and infected seeds in the dissemination of diseases. In view of the seed borne pathogens, causing substantial damage and to study the different aspects of the fungal pathogens and their effects on seed the following objectives were formulated. Foliar fungicides table ii control diseases such as tan spot, septoria tritici blotch, and eyespot. Seedborne viruses distributed to most cowpea producing regions of the worldexchange of seed legume seeds infected by viral pathogensprimary source of infection, resulting infection up to 100% economically significant and cosmopolitan. The highest total seed borne fungal infection was found in okra 26. A basic need in epidemiology is the availability of a reliable diagnostic system and information on the pathogen genomics. Sheppard abstract recognition of the importance of seedborne diseases in vegetable and flower seeds is often overlooked, particularly in the case of flower seeds.
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