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$WI LD R LATI\IES CROP PLANTS IN INDIA$

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gQ THE BRITISH SMUT FUNGI flood with a saturated solution of Bismarck brown in 70 per cent, alcohol. After seven minutes wash with 70 per cent, alcohol until only a faint brown colour remains. Flood with aniline gentian violet and leave fpr ten minutes. This stain should be freshly prepared, and for this reason the Isoloid' stains supplied by Messrs. Burroughs & Welcome Co. are useful. Drain off the violet stain and leave the slide in Gram's iodine solution for five to ten minutes. Remove surplus stain with absolute alcohol and wash in clove oil until violet is left only in the nuclei of the host and in myceHum. Wash in xylol and mount in Canada balsam. Mycelium stained deeply by this method shows up well in microphotographs. The staining capacity of hyphae varies with their age and it is not possible to get the optimum staining of old and young mycelium in the same section. Woolman (1930) found the mycelium of bunt to be Gram negative at the point of entry, Gram positive in later phases of growth. A quick method for the detection of mycelium in embryos of barley and wheat. Embryos, previously separated from the endosperm, are treated for several hours in a solution of hydrochloric acid (one part concentrated acid to three parts of water) containing 5 per cent, potassium chlorate, and then transferred to alcoholic caustic potash (20 per cent.). This bleaches and softens the tissue. After rapid neutrahzation with acetic acid the embryos are stained with aniline blue and crushed under the cover sHp. The myceHum can be seen among the dissociated cells of the host (Larose & Vanderwalle, 1939). Simmonds (1946) gives full details for separating and microtoming (10 [i) large numbers of embryos in order to compute percentage infection in a sample of seed. From 50 per cent, alcohol the slides are placed in Harris's haematoxylon for half an hour, washed in 50 per cent, alcohol, taken down to water, and stained in 5 per cent, aqueous solution of Congo red for three hours. Bismarck brown can be used to impart a golden-brown colour to hyaline promycelia and sporidia destined to be photographed. AUow most of the water to evaporate before adding absolute alcohol as a fixative. After drying leave for 20 minutes in the stain, drain off excess, and mount in 50 per cent, glycerine (McAlpine, 1910). The development of spines on the chlamydospores of U. maydis was studied by Hutchins & Lutman (1938). Sections of material fixed in Allen's modification of Bouin's fixative are transferred to water and then to a satui-ated solution of orseiUine BB solution (about 1 gm. of orseilline in 30 ml. of 3 per cent, acetic acid) for 24 hours. Alcohol (50 per cent.) is then run quickly over the shde to remove the excess stain and the sections are placed in a saturated solution (1 gm. of aniline blue in 100 ml. of 3 per cent, acetic acid) for 24 hours. The sections are dehydrated quickly by flushing with absolute alcohol, immersed in xylol, and mounted in balsam. The exospore of young spores is dark red, while the minute spines are a brilhant red in contrast to the blue gelatinous covering of the spore Anlagen. In older spores the spines are grey and finally brown.
CLASSIFICATION THE morphological characters, on which descriptions of the Ustilaginales are based, are few and relatively simple. The size and ornamentation of the spores (chlamydospores) and the structure of the sorus are of paramount importance for differentiating species on morphological grounds, and from this standpoint smuts are among the most, convenient fungi with which to work. The usefulness of herbarium material, when carefully preserved, does not deteriorate, and so the identity of successive collections is easUy checked and the exchange of material between different workers greatly faciUtated. Final proof that a species belongs to the Ustilaginales, and the determination of which of the two families (and frequently also the genus) in which a specimen should be classified depends, however, on the course of events at spore germination. The spores of herbarium specimens, after a longer or shorter time, lose their abUity to germinate and the spores of fresh material may germinate with difficulty, so that many species have been proposed, and often correctly proposed, by analogy. One object of giving, whenever possible, details of the behaviour at germination and the conditions under which this event occurs after the usual specific descriptions in the systematic treatment of the British smuts is to draw attention to the need for further studies on this phenomenon. What constitutes sufficient grounds for the differentiation of a species varies from one group of organisms to another. In general, two tendencies may be observed among students of fungi. Morphological or biological characters may be emphasized. Among smuts, as in other groups of parasitic fungi, the second attitude has been commonly adopted, and many species have been proposed from a consideration of differences in parasitic abUity towards a series of plants. Hence the identity of the host becomes of primary importance for the identification of the parasite, although not infrequently biometrical studies reveal small differences in spore-size of other characters between morphologically similar 'species' from different host plants. Butler (1929) reviewed with pertinent illustrations the criteria for the definition of species among fungi, and Ciferri (1932) expressed his views on the same subject with special reference to the smuts. Both these authors agreed that, in general, the most useful course is to defiiie-species by morphological characters and to reserve physiological and biological characters for the definition of groupings of subspecific rank, and this has been adopted as a guiding principle for the present work. Our attitude to the taxonomy of the British smuts has been conservative. We have made as few alterations as possible in both groupings and names, and whenever there is any doubt or the evidence appears to be inadequate no change has been made. Certain of the changes advocated call for comment as they affect smuts of economic importance. Cunningham (1924) and Rodenhiser (1926) each proposed the consohdation of the loose smut of wheat {Ustilago tritici) and the loose smut of barley {U. nvda) as a single species, and more recently this view has been supported by Fischer (1943). These two smuts are morphologically aUke and only differ in their pathogenicity. They may be compared with the specialized races of black rust (Puccinia graminis) which attack wheat and oats, and they should, it is felt. |V»-EG^
Page 1 and 2: THE BRITISH SMUT FUNGI ^ (USTILAGIN
Page 3: FOREWORD THIS volume was started wh
Page 6 and 7: 6 PBEFACE We also acknowledge the b
Page 9 and 10: INTRODUCTION THE smut fungi, which
Page 11 and 12: INTRODUCTION H of bushels of wheat
Page 14 and 15: FIG. 1. Vstilago avenae on Arrhenat
Page 16: ^^ THE BBITISH SMUT FUNGI Young hea
Page 19 and 20: BIOLOGY 15 less than the normal, in
Page 21 and 22: BIOLOGy 17 and united with it, fina
Page 23 and 24: BIOLOGY 19 eermination in a collect
Page 25 and 26: BIOLOGY 21 genus, and the manner of
Page 27 and 28: BIOLOGY 23 species of Entyloma, and
Page 29 and 30: 3036^ BIOLOGY 25 in others. Dickins
Page 31 and 32: CYTOLOGY THE discovery of nuclei in
Page 33 and 34: GENETICS INCOMPATIBILITY KNIEP'S di
Page 35 and 36: GENETICS • 31 direction of growth
Page 37 and 38: GENETICS 35 when a few sporidia fro
Page 39 and 40: GENETICS 37 lines retained their di
Page 41 and 42: TECHNIQUE COLLECTION AND EXAMINATIO
Page 43 and 44: TECHNIQUE 41 be undesirable. Weak a
Page 45 and 46: TECHNIQUE 43 in one season (see p.
Page 47 and 48: TECHNIQUE 45 barley with loose smut
Page 49 and 50: TECHNIQUE 47 (1939), Holton & Heald
Page 51: TECHNIQUE 49 Allen's, modification
Page 55 and 56: THE BRITISH SMUT FUNGI MOST of the
Page 57 and 58: FIG. 2. Spore geimination in Ustila
Page 59 and 60: THE BRITISH SMUT FUJJGI 57 from one
Page 61 and 62: THE BRITISH SMUT FUKGI 59 of exsert
Page 63 and 64: THE BRITISH SMUT FUNGI 61 noticeabl
Page 65 and 66: THE BRITISH SMUT FUNGI 63 Evidence
Page 67 and 68: THE BRITISH SMUT FUNGI 65 winter in
Page 69 and 70: THE BRITISH SMUT FUNGI 67 Ustilago
Page 71 and 72: THE BRITISH SMUT FUlJGI 69 material
Page 73 and 74: THE BRITISH SMUT FUNGI 71 results o
Page 75 and 76: THE BRITISH SMUT FUNGI 73 TTstilago
Page 77 and 78: THE BRITISH SMUT FUNGI 75 Species i
Page 79 and 80: " TJSE BRITISH SMUT FUNGI 77 Ustila
Page 81 and 82: THE BKITISH SMUT FUNGI 79 On Carex
Page 83 and 84: THE BRITISH SMUT FUNGI 81 Exsiccati
Page 85 and 86: THE BRITISH SMUT FUNGI 83 Tilletia
Page 87 and 88: THE BRITISH SMUT FUNGI 85 bunt ball
Page 89 and 90: THE BEITISH SMUT FUNGI 87 globose t
Page 91 and 92: THE BRITISH SMUT FUNGI 89 FIG. 13.
Page 93 and 94: FIG. 15. Spore geimination in Taboi
Page 95 and 96: FIG. 17. Spore germination in Urocy
Page 97 and 98: THE BRITISH SMUT FUNGI 95 separate
Page 99 and 100: THE BRITISH SMUT FUNGI 97 8ori in t
Page 101 and 102: THE BRITISH SMUT FUNGI 99 Urocystis
Page 103 and 104:
30390 THE BRITISH SMUT FUNGI 101 pr
Page 105 and 106:
FIG. 20. Spore geimination in Entyl
Page 107 and 108:
THE BRITISH SMUT FUNGI 105 Sori in
Page 109 and 110:
On Ranunculus ficariae and B. scler
Page 111 and 112:
THE BRITISH SMUT FUNGI 109 Infectio
Page 113 and 114:
THE BKITISH SMUT FUNGI 111 [Sporidi
Page 115 and 116:
THE BRITISH SMUT FUNGI 113 Ustilago
Page 117 and 118:
REFEEENCES 115 BBETT, M. A. (1940).
Page 119 and 120:
REFERENCES 117 ^ DniON WESTON, W. A
Page 121 and 122:
REFERENCES 119 GRIFFITHS, MAEIOK A.
Page 123 and 124:
REFERENCES 121 HtjTTiG, W. (1933).
Page 125 and 126:
REFEBENCES 123 LiMBOtruN, E. J. (19
Page 127 and 128:
REFERENCES 125 NOBLE, E. J. (1934).
Page 129 and 130:
REFERENCES 127 RoDENHiSEE, H. A., &
Page 131 and 132:
BEFERENCES 129 STAKMAK, E. C, XCEEN
Page 133 and 134:
EEFEEENCES 131 WAXTBE, J. M. (1934)
Page 135 and 136:
INDEX to generic and specific names
Page 137 and 138:
Muscari Ustilago vaillantii, 59 Myo
Page 139 and 140:
Ustilago ficuum Reich., 113 —flps
Page 141 and 142:
2i}:y0 ANDHRA PRADESH AGRICULTURAL
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