Introduction to seed Pathology Session1 Disease causing agents
- Slides: 6
Introduction to seed Pathology Session-1
Disease causing agents of seeds I. Biotic agents: (i). Fungi (ii). Bacteria (iii). Mycoplasma (iv). Nematode II. Meso- biotic agents: (i). Virus (ii). Viroids III. Abiotic agents: i). Nutritional disorder – Hollow heart of ground nut – B, yellow berry of wheat – N- deficiency
Why seed is considered as the more preferred destination of pathogens than other parts of plant? (i) Seed is most important & nutritionally rich part of plant (ii) Seed does not offer any resistance to the invading pathogen (iii) Seed contains lowest amount of the moisture which helps pathogen to perennate inside the seed as dormant condition. (iv) It provides longer, safe period of survival and transmission to some pathogens. (v) It offers less competition among the microorganisms than in soil. (vi) It provide suitable host and condition for infection by pathogen
Why should we study the seed pathology? (i) Seed is the most important basic input of agricultural production. (ii) Infected seeds are important foci of plant pathogen infection, responsible for disease development (iii) Disease affects seed quality. Seed is important source of long and safe mode (less competition) of perennation and dissemination/ distribution of pathogen breaking geographical barrier, germplasm exchange. (iv) If the seeds are not healthy – if it is shriveled, wrinkled, dis-coloured, rotted- affect viability, germination, plant stand, seedling vigour, yield - crop loss and economic loss.
Why should we study the seed pathology? (v) Need extra expenditure for management of seed borne disease- including quarantine, infrastructure development (vi) Seed borne pathogens are source of poisonous toxins (vii) Legal restriction is imposed on import and export of seeds. (viii) Seed industry is responsible quality seed production (ix) Diseased seed may help the introduction of new strain of physiologic races (x) Scope for employment in quality seed production, laboratory testing, quality control, certification
Important attributes of seed for seed industry (i). Physical & genetic purity. (ii). High germinability. (iii). Freedom from the seed borne diseases
