Grafting is a method of asexual propagation where two living plant parts (the rootstock and scion) are united together to grow as a single plant. Although grafting in fruits and nuts is an ancient technique, vegetable grafting is relatively a recent innovation and has emerged as one of the most important integrated pest management strategy to manage soil borne pathogens and insect pests of solanaceous and cucurbitaceous vegetable crops at the turn of 20th century. The earliest reports from Japan included the use of Cucurbita moschata to confer Fusarium wilt resistance in watermelon production (Oda 2002; Sakata et al 2007, 2008). Grafting as a disease management tactic has rapidly expanded to solanaceous and cucurbitaceous vegetables due to the factors viz. increased pathogen inoculum densities due to intensification of production practices, reliance on susceptible cultivars to meet specific market demands , global movement and local invasion of novel pathogens, increased use of organic practices, the rapid adoption of high tunnel production systems, use of appropriate technologies for resource-limited farmers and the ban on methyl bromide via Montreal Protocol (Sakata et al 2007). The recent use of semi-automated grafting machines and grafting robots ensures higher grafting speed, higher survival rate of grafted plants, reduces the higher price of grafted seedlings, and thus encourages the cultivation of grafted plants among small-scale farmers. In addition, grafting provides advantages to manage abiotic stress, to reduce reliance on chemical and fertilizer inputs, and to enhance fruit quality and yield (Colla et al 2010a, b; Proietti et al 2008; Rouphael et al 2008a, b).
Table of Contents
1. Introduction
2. History of Grafting in Vegetables
3. Current Status of Vegetable Grafting
4. Diseases controlled by Grafting in Vegetable production
5. Approaches to combat biotic stress in vegetable grafting
5.1 Intraspecific grafting
5.2 Interspecific grafting
6. Basic Prerequisites of Grafting
7. Grafting methods in Vegetables
8. Defense mechanisms in disease resistance of grafted vegetables
9. Success Stories of Grafting as an effective approach against soil borne pathogens in vegetable production
10. Dangers of Grafting
11. Future Prospects
12. Conclusions
13. References
Objectives & Core Topics
This review aims to explore the utilization of vegetable grafting as a strategic integrated pest management (IPM) tool for the mitigation of soil-borne diseases and the enhancement of vegetable productivity. The study investigates how grafting facilitates the management of various pathogens in solanaceous and cucurbitaceous crops, improves tolerance to abiotic stressors, and optimizes fruit yield and quality, while also addressing the potential risks and future directions of this agricultural technique.
- Mechanisms of disease resistance in grafted vegetable plants.
- Methods and prerequisites for successful vegetable grafting.
- Management of soil-borne fungal, bacterial, and nematode pathogens through specific rootstocks.
- Impact of grafting on plant vigor, nutrient uptake, and stress tolerance.
- Protective role of the rhizosphere and systemic defense induction.
Excerpt from the Book
1.1 What is Grafting?
Grafting is a method of asexual propagation where two living plant parts (the rootstock and scion) are united together to grow as a single plant. Grafting is a fusion of plant parts so that vascular continuity is established between them and the resulting genetically composite organism functions as a single plant (Mudge et al 2009). In grafting, one plant is selected for its roots which is generally meant for disease resistance against soilborne pathogens and plant vigour benefits and this is called the rootstock. The other plant is selected for its stems, leaves, flowers, or fruits which is commonly meant for qualitative and quantitative horticultural traits and is called the scion.
The graft union is initially formed by rapidly dividing callus cells, originating from the scion and rootstock, which later differentiate to form the vascular cambium (a lateral meristem) and the associated vascular system. The development of a compatible graft is typically comprised of several major events: adhesion of the rootstock and scion, proliferation of callus cells at the graft interface or callus bridge, and vascular differentiation across the graft interface.
Summary of Chapters
1. Introduction: Discusses the prevalence of soil-borne pathogens in vegetable production and introduces grafting as a sustainable, integrated management strategy.
2. History of Grafting in Vegetables: Outlines the origins of vegetable grafting in Japan and Korea during the 1920s and its subsequent global expansion.
3. Current Status of Vegetable Grafting: Provides statistical data on the adoption of grafting techniques across various countries for cucurbitaceous and solanaceous crops.
4. Diseases controlled by Grafting in Vegetable production: Lists major fungal, oomycete, bacterial, and nematode pathogens that are effectively suppressed by grafting.
5. Approaches to combat biotic stress in vegetable grafting: Details the differences between intraspecific and interspecific grafting strategies for combating biotic stress.
6. Basic Prerequisites of Grafting: Defines the essential requirements, including rootstock selection, scion traits, and necessary environmental infrastructure for grafting success.
7. Grafting methods in Vegetables: Describes technical grafting procedures such as cleft grafting, tongue approach grafting, tube grafting, and hole insertion grafting.
8. Defense mechanisms in disease resistance of grafted vegetables: Explains biological mechanisms, including inherent rootstock resistance, microbial shifts in the rhizosphere, and induced systemic defense.
9. Success Stories of Grafting as an effective approach against soil borne pathogens in vegetable production: Presents specific case studies on managing diseases like Verticillium wilt, Fusarium wilt, and root-knot nematodes.
10. Dangers of Grafting: Addresses risks such as the transmission of seed-borne pathogens and the potential for pathogen populations to shift or evolve due to rootstock reliance.
11. Future Prospects: Analyzes the potential for improved multi-disease resistant rootstocks and automated grafting technology to enhance sustainable horticulture.
12. Conclusions: Reaffirms grafting as a vital alternative to traditional breeding and soil disinfection for achieving sustainable vegetable production.
Keywords
Vegetable grafting, Rootstock, Scion, Soil-borne pathogens, Integrated pest management, Fusarium wilt, Verticillium wilt, Bacterial wilt, Root-knot nematodes, Abiotic stress, Systemic acquired resistance, Callus bridge, Sustainable horticulture, Disease resistance, Rhizosphere microbial diversity.
Frequently Asked Questions
What is the core focus of this research paper?
This work fundamentally examines the application of vegetable grafting as an integrated pest management tool to mitigate soil-borne diseases and improve overall crop health and productivity in vegetable farming.
What are the primary thematic areas covered?
The paper covers the history of grafting, the technical prerequisites and methods of grafting, the underlying biological defense mechanisms, successful control of specific pathogens, and the potential future advancements in grafting technology.
What is the primary objective of this review?
The primary objective is to evaluate how grafting enhances resistance to biotic and abiotic stresses, thereby reducing reliance on chemical pesticides and methyl bromide, and providing a sustainable pathway for vegetable production.
Which scientific methods are analyzed?
The paper analyzes diverse grafting techniques including cleft, tongue approach, tube, and hole insertion grafting, alongside studies on gene expression, proteomics, and soil microbiology in the rhizosphere of grafted plants.
What is discussed in the main body of the text?
The main body details the biological mechanisms of graft-induced disease resistance, evaluates specific success stories across various vegetable crops, and addresses the critical risks associated with grafting, such as seed-borne pathogen transmission.
How can one define the most important keywords for this work?
The key terms center on the practice itself (vegetable grafting), its main components (rootstock, scion), the problems it solves (soil-borne pathogens, Fusarium, Verticillium), and its benefits (sustainable horticulture, systemic resistance).
How does grafting facilitate systemic defense in plants?
Grafting induces systemic defense through the activation of plant-pathogen recognition pathways, the production of defense-related enzymes (such as PAL), and long-distance signaling of mobile molecules like proteins and RNA across the graft union.
What impact does rootstock selection have on managing soil-borne diseases?
Rootstock selection is crucial because it provides the first line of defense through inherent genetic resistance, improves plant nutrient uptake, and modulates the rhizosphere microbial population to suppress the growth of pathogens.
Are there any specific risks associated with the practice of grafting?
Yes, significant risks include the potential for mechanical transmission of seed-borne pathogens during the grafting process and the risk of emerging or virulent pathogen strains developing due to the heavy reliance on specific, narrow-spectrum rootstocks.
- Citation du texte
- Ritesh Yadav (Auteur), 2018, A comprehensive review on management of soil borne diseases through vegetables grafting, Munich, GRIN Verlag, https://www.grin.com/document/444420
