Ustilago tritici by sohail mycology

Classification
Introduction
Infection
Symptoms
Reproduction
Life cycle
Clamp connection

1. USTILAGO TRITICI

2. Presented by: Muhammad Sohail Riaz Presented to: DR Umair Ahmad Awan

3. Table of Contents Classification Introduction Infection Symptoms Reproduction Life cycle Clamp connection

4. Cont …. Differ between covered & loose smut Ways to control the disease

5. Classification Kingdom: Fungi Phylum: Basidiomycota Class: Ustilaginomycetes Subclass: Ustilaginomycetidae Order: Ustilaginales Family: Ustilaginaceae Genus: Ustilago Species: U. tritici

6. Introduction It is also called as loose smut of wheat Seed borne systemic disease Causes heavy damages to barley, rye , specially wheat Cool and moist environments are most suitable for the fungus growth

7. Infection Embryo mode of infection Seed borne Active at time of seed germination Very difficult to identify effected seed and healthy one

8. Symptoms Symptom appear on emergence of inflorescence Deformed spikelet are produced on plants Soon the part of inflorescence is replaced by smut spores and black powdery mass Effected kernals emerge slightly healthier one

9. S mut spores

10. Plant body: Mycelium Primary mycelium: It is monokaryotic , produced by germination of basidiospores Slender hyphae, hyaline, septate, each contain single haploid nucleus They are short lived

11. Cont ….. Secondary mycelium: It is dikaryotic , produced by plasmogamy through sexual reproduction Extensive, septate, intercellular each contain binucleated They are capable of infection

12. Reproduction Ustilago reproduces by teliospores They have following characteristics Produced on dikaryotic mycelium Made up of two layers Outer thick , pigmented , sometimes ornamental with spines or reticulations At younger stage they are binucleated but at maturity it converted into diploid nucleu

13. Methods of dikaryotization in Ustilago Somatogamy Copulation of basidiospores Infection threads Fusion of germ tubes

14. From monokaryotic to dikaryotic

15. LOOSE SMUT OF WHEAT

16. Life cycle of Ustilago tritici

17. Graphic life cycle of Ustilago tritici

18. Clamp connection A clamp connection is a hook-like structure formed by growing hyphal cells of certain fungi It is created to ensure each cell, or segment of hypha separated by septa (cross walls), receives a set of differing nuclei, which are obtained through mating of hyphae of differing sexual types

19. Differ between covered & loose smut

20. Ways to control the disease Since the mycelium is internally seed-borne, external application of fungicides normally remains ineffective There are following ways to control it: Roguehing Seed selection Hot water treatment Solar treatment Anaerobic seed treatment Use of systemic fungicides Resistant varieties

21. Rogueing In this method the wheat plants with infected ears, which emerge out earlier than the healthy ones, are uprooted and burn

22. Seed selection As the disease is seed borne so careful selection of seed must be don

23. Hot Water Treatment This method was evolved by Jensin (1889) against late blight of potato. However, Swingle1892. Freeman and Johnson (1909) used this method against loose smut of wheat. It consists of two steps: Soaking the seeds in ordinary cold water (26-30°C) for four hours Duping in hot water (54°C) for 10 minutes, and finally drying the grains before sowing. The first step reduces the dormant mycelium to germinate while the second step helps in killing the germ tubes.

24. Solar Heat Treatment This method is applicable in those regions where the summer temperature is very high (42-44°C). It was suggested by Luthraand Sattar(1934). Following two steps constitute this method: The seeds are soaked in water for at least four hours (8 am to 12 noon) on a bright summer day After this stage the seeds are dried in the sun for 4 hours from 12 noon to 4 p.m. The germinating dormant mycelium is killed as a result of the action of the direct sun rays of hot summer

25. Anaerobic Seed Treatment Soaking the seeds for 2-4 hours in water between 6070°C Keeping the moist seeds in air tight containers for 6570 hours and thereafter drying them

26. Growing Resistant Varieties It is the best method for avoiding the disease. Wheat varieties NP165, Pb9D. Bansi O.P., NP797, NP824, Kalyan 227, Pv 18, WG 307 and C 302 have been found to be resistant to this disease

27. Use of Fungicides In this method seeds are treated with Benomyl and Carboxin ( vitavax , 0. 2 – 0.25%) or fungicides like Agrosan , spergon , ceresan , formaline and fine sulphur

28. Crop rotation This method has also proved satisfactory in controlling this disease to some extent