Annals Of Botany Research Articles

Use of Statistical Tests of Equivalence (Bioequivalence Tests) in Plant Pathology

Hypothesis tests currently used in plant pathology are almost always based on a null hypothesis of equal means. In this framework, the experimenter determines whether or not there is evidence that the means are, in fact, different. This framework makes sense for many common questions such as whether a new management technique gives an increase in yield over existing management techniques. But suppose, for example, that a disease management technique is so effective that an experimenter is interested in whether its use in the presence of disease achieves the same yield as in the absence of disease. In this case, a more appropriate null hypothesis would be that mean yields are different. Examples of questions in plant pathology for which a null hypothesis of equal treatment means is not suitable include (corresponding phrasing for one-sided questions is in parentheses as appropriate):

Microsatellite Libraries Enriched for Several Microsatellite Sequences in Plants

Microsatellite Libraries Enriched for Several Microsatellite Sequences in Plants

Identification of breakpoints in intergenotypic recombinants of HIV type 1 by bootscanning.

Identification of breakpoints in intergenotypic recombinants of HIV type 1 by bootscanning.

Will the Real Self‐Thinning Rule Please Stand Up?‐‐A Reply to Osawa and Sugita

Causton, D. R., and J. C. Venus. 1981. The biometry of plant growth. Edward Arnold, London, England. Chester, A. L., and J. B. McGraw. 1983. Effects of nitrogen addition on the growth of Vaccinium uliginosum and Vaccinium vitis-idaea. Canadian Journal of Botany 61:23162322. Chiariello, N. R. 1989. Plant populations and ecophysiology. Bulletin of the Ecological Society of America 70:6263. Fetcher, N., and G. R. Shaver. 1983. Life histories of tillers of Eriophorum vaginatum in relation to disturbance. Journal of Ecology 71:131-148. Garbutt, K., and F. A. Bazzaz. 1983. Leaf demography, flower production and biomass of diploid and tetraploid populations of Phlox drummondii Hook. on a soil moisture gradient. New Phytologist 93:129-141. Harper, J. L. 1980. Plant demography and ecological theory. Oikos 35:244-253. Hunt, R. 1978. Demography versus plant growth analysis. New Phytologist 80:269-272. 1982. Plant growth curves: an introduction to the functional approach to plant growth analysis. Edward Arnold, London, England. Hunt, R., and F. A. Bazzaz. 1980. The Biology of Ambrosia trifida L. V. Response to fertilizer with growth analysis at the organismal and sub-organismal levels. New Phytologist 84:113-121. Kauffman, K. W. 1981. Fitting and using growth curves. Oecologia (Berlin) 49:293-299. Maillette, L. 1982. Structural dynamics of silver birch. II. A matrix model of the bud population. Journal of Applied Ecology 19:219-238. McGraw, J. B. 1989. Effects of age and size on life histories and population growth of Rhododendron maximum shoots. American Journal of Botany 76:113-123. McGraw, J. B., and J. Antonovics. 1983. Experimental ecology of Dryas octopetala ecotypes. II. A demographic model of growth, branching and fecundity. Journal of Ecology 71: 899-912. Ondok, J. P. 1971. Indirect estimation of primary values used in growth analysis. Pages 343-391 in Z. Sestak, J. Catsky, and P. G. Jarvis, editors. Plant photosynthetic production. Manual of methods. Dr. W. Junk, The Hague, The Netherlands. Parsons, I. T., and R. Hunt. 1981. Plant growth analysis: a curve-fitting program using the method of B-splines. Annals of Botany 48:341-352. Porter, J. K. 1 983a. A modular approach to analysis of plant growth. I. Theory and principles. New Phytologist 94:183190. 1983b. A modular approach to analysis of plant growth. II. Methods and results. New Phytologist 94:183190. SAS (Statistical Analysis Systems). 1985. SAS user's guide: statistics. SAS Institute, Cary, North Carolina, USA. Schmitt, J., J. Eccleston, and D. W. Ehrhardt. 1987. Dominance and suppression, size-dependent growth and selfthinning in a natural Impatiens capensis population. Journal of Ecology 75:651-666. Shaver, G. R. 1981. Mineral nutrition and leaf longevity in an evergreen shrub, Ledum palustre ssp. decumbens. Oecologia (Berlin) 49:362-365.

The Centenary of the Annals of Botany

The Centenary of the Annals of Botany

Fixation of elemental nitrogen by marine blue-green algae : Stewart, W.D.P. 1962. Annals of Botany, 26(103): 439–446.

Fixation of elemental nitrogen by marine blue-green algae : Stewart, W.D.P. 1962. Annals of Botany, 26(103): 439–446.

Structure of the male gametophyte in gymnosperms.

Structure of the male gametophyte in gymnosperms.

Electrodes for blood pO2 and pCO2 determination.

Electrodes for blood pO2 and pCO2 determination.

Experimental and Analytical Studies of Pteridophytes

IN our this knowledge paper experimental of phyllotaxis observations in ferns; but are a full set consideration out which contribute of this comto our knowledg of phyl taxi in ferns but a full consideration of this omplex subject must be reserved until later. These observations relate to the induction of tangential tensile stress in the shoot apex as a result of the growth of the young leaf-primordia. The view is advanced that such stresses constitute one of the factors which determine the position of new leaf-primordia. During the formation of the individual leaf-primordium in a fern such as Dryopteris aristata, a conspicuous enlargement of the basal region takes place, particularly in the tangential direction. This is mainly due to the development of parenchyma in the pith and cortex. In a very young primordium, as seen in transverse section, the incipient vascular tissue consists of an uninterrupted crescent of small-celled tissue. The growth of this tissue does not keep pace with the growth of the pith, and it becorties broken up into a number of separate strands or meristeles, i.e. apparently as a result of the tangential stress imposed by the pith or jointly by the pith and cortex (Wardlaw, 1944, 1945). The incipient vascular tissue in the regions of disruption undergoes a parenchymatous development; in other words, potential phloem and xylem are transformed into parenchyma. Experimental evidence of this phenomenon has also been obtained (Wardlaw, 1947). In relation to these developments in the leaf-primordia, the incipient shoot-stele, which initially consists of an uninterrupted cylinder, is also subjected to tensile stress in the regions of insertion of the leaf-traces, and parenchymatous leaf-gaps develop. The adult stele thus consists of an open vascular meshwork or dictyostele. These conceptions of stelar morphology in ferns were based on anatomical studies of development at the shoot apex. Experimental proof that leaf-gaps are due to the enlargement of the leaf-bases was sought by destroying leaf-primordia at a very early stage: by this procedure the development of local stresses would be avoided and the vascular cylinder would remain uninterrupted, i.e. solenostelic. When the appropriate experiment was carried out the result predicted was obtained (Wardlaw, 1944). Such observations suggest that at the apical meristem of ferns a conical [Annals of Botany, N.S. Vol. XII, No. 46, April, 1948.] 966.46 H

Spontaneous Hybrids between Sonchus asper and S. oleraceus

CļONCHUS OLERACEUS L. and S. asper Hill are closely related in morO phology. S. asper differs from S . oleraceus in its more spiny, thicker, and often darker green leaves. It is usually a stouter and more compact plant than S . oleraceus. But the most important differences are in the shape of the auricles and the structure of the fruit. In asper the auricles are nearly circular, with a spiny margin and closely appressed to the stem (Fig. i). In oleraceus the auricles are spreading, arrow-shaped and often deeply toothed (Fig. 3). The fruit in asper is without the transverse ribs of oleraceus. In most of the recent floras the species are separated, although in some of the earlier ones (e.g. Bentham and Hooker) asper is considered as being only a 'marked variety'. Both species are annual and very common weeds of arable land in all temperate regions of the world. Hybrids between the two have been reported previously by Hegi and in the London Catalogue. They are said to be rare. Both species are self-fertile. S. oleraceus occurs in two forms distinguished by chromosome number. A diploid has been reported by Marchai (1920) with zn = 16 chromosomes, and a tetraploid with zn = 32 by Ishikawa (191 1) and by Cooper and Mahony (I935)The Merton plants were of the tetraploid type (see Fig. 6), which seems therefore to be the more widely distributed. The chromosome number of S. asper has not previously been determined. Two families, consisting of 12 and 23 plants, were raised at Merton from open pollination of two typical plants of S. asper . The seedlings in the larger family were all likewise typical S. asper and fertile. The somatic chromosome number was 18 (Fig. 4). Evidently they were diploid, with a basic number of 9. In the smaller family there were three typical S. asper plants, which were also fertile. The chromosome number was again 18. The remainder showed some resemblance to S. oleraceus. Their habit was looser and more branched, and the leaves were hardly more spiny than the typical S. oleraceus. The auricles of the later leaves, however, were more like those of S . asper , except that one tooth was much bigger than the others and projected backwards (see Fig. 2). [Annals of Botany, N.S. Vol. V, No. 18, April 1941.]

NOTICES

Journal Article NOTICES Get access The Occlusion of Pruning Wounds in Norway Spruce (Picea excelsa) . By A. PATERSON . Annals of Botany , New Series vol. ii (7). 1938 . Forestry: An International Journal of Forest Research, Volume 13, Issue 1, 1939, Page 98, https://doi.org/10.1093/oxfordjournals.forestry.a062803 Published: 01 April 1939

The Development of the Flowers from the Curd of Broccoli (Brassica oleracea botrytis)

THE oleracea structure botrytis) of the appears head or in curd the literature of the broccoli to have and been cauliflower misunderstood. {Brassica oleracea botrytis) appears in th literature have been misu derstood. Masters (1849) says: 'The cauliflower and broccoli afford familiar illustrations of the hypertrophy of the flower stalk accompanied by a corresponding defective development of the flowers' (p. 421). According to Worsdell (1915), ' . . the whole inflorescence becomes greatly hypertrophied, involving very copious branching of the pedicellar system, and in which the flowers are completely suppressed, has given rise to the variety of the cabbage known as the cauliflower . . .' (vol. ii, p. 40), and 'Examples are afforded by the cauliflower and broccoli, in which, owing to excessive hypertrophy of the pedicels, the flowers are not developed, or only a vestigial calyx' (p. 248). From this it would appear that the curd has developed into a purely vegetative organ. Actually the whole inflorescence is hypertrophied, but the flowers are not defective, the curd being merely an intermediate stage in the development of the flowers and seed. After the curd has developed it is rapidly disrupted by the elongation of the main stalks to varying degrees. Plate XXIX, Figs 1-6, show successive stages in the further development of one of these pieces of the disrupted curd. Fig. i. ist day, the masses of white hypertrophied flowers are separating by the elongation of the secondary stalks. Fig. 2. 3rd day, the stalks are elongating further and losing their fleshy character. The white curd is developing pigment (in the centre at 2 o'clock), while (at 10 o'clock) pigment has been developed and the hypertrophied bud tissue has begun growing out into buds. Fig. 3. 6th day, the same processes are continuing and the buds in the centre mass have now differentiated their sepals. Fig. 4. 8th day, the minor branches are continuing to elongate and the pedicels of the buds are lengthening. At the right-hand side is a partially differentiated mass of buds that is beginning to abort; probably due to starvation, as it did not appear to have suffered any injury. Fig. 5. 17th day, here the buds are nearly ready to burst-. The aborted [Annals of Botany, N.S. Vol. II, No. 7, July 1938.]

Prof. Frank Cavers

PROF. FRANK CAVERS, whose premature death occurred on May 26, was educated as a botanist at the University of Leeds, under the stimulating influence of the late Prof. Miall, whose heuristic methods attracted much attention in the early years of the century. After leaving the University, Cavers held teaching posts in botany at Hartley College, Southampton, and later at the Goldsmiths' College in London. He was not, however, in all respects well fitted for such work, though he was an excellent botanist and a most lucid expositor of his subject, as was shown by a number of elementary text-books models of their kindwritten for the University Correspondence College. He made a special study of the Bryophyta, publishing the results of his admirable researches in the Annals of Botany, the New Phyto-logist, and elsewhere, and obtaining the D.Sc. degree of the University of London.

Further Studies on Transport in the Cotton Plant IV. On the Simultaneous Movement of Solutes in Opposite Directions through the Phloem1

IT type would of mechanism appear that involved plant physiologists in the longitudinal are not transport yet agreed of as materials to the type of mechanism involved n the lon itudinal ransport of m terials through the sieve-tube. Munch (8) has elaborated a theory involving a directed mass flow of solution, while others (1, 4) favour a movement of solute rather than solution and stress (2) the resemblance between the gross phenomena of transport and diffusion. The Druckstrom theory possesses a completeness and simplicity that has much to recommend it, while the theory of activated diffusion is rather vague concerning the method whereby diffusion through the sieve-tube is accelerated. As protoplasmic streaming has apparently to be rejected as a method of accelerating diffusion, and as respiration appears to be a factor in transport, the suggestion (7) has been 1 Paper No. 13 from the Physiological Department of the Cotton Research Station, Trinidad. [Annals of Botany, Vol. L. No. CXCVII, January, 1936.] M

University and Educational Intelligence

LONDON.—The degree of D.Sc. has been conferred on the following: W. Youngman, for a thesis entitled “Further Studios in the Cytology of the Hibiceæ”, with two subsidiary contributions; S. E. Hollingworth, for a thesis entitled “The Glaciation and Physiographic Development of the Eden Catchment Basin West of that River, and the Drumlins of Edenside and the Solway Basin”, with two subsidiary contributions; Lin. L. Lee (Rothamsted Experimental Station), for a thesis entitled “The Influence of Geology and Climates on Soil Types” (Jour. S.E. Agric. Coll., June 1931); A. N. Puri (Rothamsted Experimental Station), for a thesis entitled “Studies in Soil Colloids” (Memoirs of Dept. of Agriculture, 1930; Soil Science, 1930–31); A. J. Maslon (Chelsea Polytechnic), for a thesis entitled “The Structure of Mesoxylon Platypodium and Mesoxyliodes” (Annals of Botany, July 1930); L. R. Underwood (Imperial College—City and Guilds College and East London College), for a thesis entitled “The Combustion of an Oil Jet in an Engine Cylinder”.

Mrs. D. H. Scott

BY the death of Victoria Henderina Scott, which took place quite suddenly at her home at Oakley, Hants, on Jan. 18, the Linnean Society loses one of its earliest women-fellows, and botany a keen and loyal supporter. Mrs. Scott was elected a fellow of the Linnean Society in February 1905, following the grant of the supplemental charter which removed the sex distinction. Her active interest in the Society's work was illustrated by an exhibition, shortly after, of a series of animated photographs, taken by the kinematograph, showing opening and closing of flowers, and other plant movements. Until recent years she was a frequent attendant at the meetings of the Society, and in 1911 gave a lantern exhibition of a new species of the fossil genus Traquaria. Communications on plant fossils and other subjects were also contributed to the New Phytologist and the Annals of Botany. In the preface to the second edition of the “Studies in Fossil Botany”(1909), Dr. D. H. Scott acknowledges the help of his wife in the preparation of some of the illustrations; and a similar service had been rendered in his “Introduction to Structural Botany”(1894-96).

Selective Action of Polarised Light upon Starch Grains

IT was with much interest that I read the letter relating to the action of polarised light on starch hydrolysis contributed to NATURE of December 5 by Prof. Baly and Dr. Semmens. This letter, since the writers refer to a short “note” by myself in the Annals of Botany (July 1925), calls for a brief reply.

Selective Action of Polarised Light upon Starch Grains

IN a recent note (Annals of Botany, 39, 651, 1925) Prof. Neilson Jones has criticised our statement (Proc. Roy. Soc. 97 B, 250, 1924) that starch grains are selectively hydrolysed by polarised light in the presence of small quantities of diastase. Prof. Jones is under a misapprehension when he says that we accepted the frilling or serration of the grains as evidence of hydrolysis. We did not do so, for what we observed was the complete disappearance of the starch grains when illuminated with polarised light, slight serration only occurring in heterogeneous light. Further, after complete hydrolysis of the starch grains by polarised light, the solution deposited crystals which reduced Fehling's solution.

An Endotrophic Fungus in the Coniferæ

IN a communication to NATURE of December 13, Prof. F. J. Lewis directs attention to the discovery of intercellular mycelium in the shoot tissues of Picea canadensis and other conifers, and also in roots and shoots of Ledum palustre and Vaccinium Vitis-idi. Referring to the two last-named species, Prof. Lewis writes: an examination of the root and stem of Ledum palustre and Vaccinium Vitis-ida from this district has been made, and an endotropic [?endotrophic] fungus has been found similar to that described by Rayner (Annals of Botany, 1915) in European material".

The Occurrence of Urease

LETTERS on the occurrence of urease are printed in NATURE of August 11 and September 22. In the former, Prof. Werner reports that he has found urease in all the leguminous nodular growths he has tested; in the latter, Prof. Beijerinck describes how he has detected the enzyme in B. radicicola. Prof. Werner writes: “So far as we have been able to ascertain, the peculiar root nodules of leguminous plants have not hitherto been tested for urease.” I reproduce, therefore, the following passage from an article on “The Function of Hormones in regulating Metabolism,” by my son and myself, published in the Annals of Botany, vol. xxv., No. xcviii., April 1911.