Thalictrum Species Research Articles

Alkaloids of far-eastern species ofThalictrum. IV

The alkaloid composition of four far-eastern species ofThalictrum — Th. amurense, Th. contortum, Th. filamentosum, andTh. minus — have been studied, for the first time in the case of the first three species.Th. amurense contains β-allocryptopine and thalictrisine, andTh. contortum contains β-allocryptopine. Glaucine and thalicsimidine have been found inTh. filamentosum, and argemonine has been isolated fromTh. minus for the first time.

Flavon- C- und O-glykoside in Thalictrum-arten

From the aerial parts of three Thalictrum species the flavone- C-glycosides vitexin, saponaretin, orientin and Iso-orientin and the flavone- O-glycosides quercetin-3-rutinoside and kaempferol-3-rhamnoglucoside were isolated or identified chromatographically.

Thin-layer chromatography of thalictrum species alkaloids

Thin-layer chromatography of thalictrum species alkaloids

A new octadecenoic acid

It has been shown that the fatty oils of five species of Thalictrum contain trans-octadec-5-enoic acid. This acid may be regarded as a chemicophysiological classification index of plants of the genus Thalictrum.

Pharmacological Screening of Various Species of Thalictrum III

Eleven different species of Thalictrum have been examined for hypotensive and smooth muscle relaxing effects. Thalictrum minus race B, T. rochebrunianum , and T. rugosum appeared to be the most promising and worthy of further investigation.

Thalictrum cooleyi Sp. Nov.

Planta 38-73 cm alta. Folia inferiora semper fere 2-ternata, raro 1-ternata aut 3-ternata. Foliola inferne glauca, margine revoluto, valde angusta, raro lobata. Planttae dioicae. Inflorescentita paniculata. Pedicelli 2-20 mm longi. Flores masculi flavi pallidi. Filamenta clavata, purpurea pallida, 2-3 mm longa. Antherae oblongo-lanceolatae, obtusae, flavae. Carpella matura 4.5-6 mm longa et 1.5-2.5 mm lata, ellipsoidea, glabra, sessilia vel subsessilia, 8-10 nervis conspicuis. This new species of Thalictrum was collected in the late spring and early summer of 1957 during extensive field work for "The Flora of the Carolinas," a project undertaken by a number of members of the Botany Department of the University of North Carolina. It is named in honor of George R. Cooley, a retired New York businessman, who is much interested in the flora of the southeastern United States. He has been and is actively supporting much research in this field. Thalictrtum cooleyi belongs to the section Leucocoma (Greene) Boivin. To this section belong T. dasycarpum, T. revoluturm, T. p,olygawmumn, T. macrostylum, and T. s'ubrotundum. It differs from all of these in having lavender instead of white filaments, narrowly lanceolate instead of oblong to ovate leaflets, and fewer leaf-divisions. Thalictrum cooleyi is a very slender-stemmed, glabrous plant averaging 47 cm in height with an infloreseence averaging 7 cm in length. The very lax stems are usually supported by surrounding vegetation. The caudex is short with a fibrous root system. The 3-5 basal leaves are mostly 2-ternate, rarely 3or 1-ternate. The three or foPr, rarely five, cauline leaves decrease rapidly upward both in size and in number of divisions, and are separated from one another by long internodes. The upper leaves, usually 1-ternate, are frequently sessile, occasionally subsessile or on short petioles up to 1 cm long. The leaflets, glaucous beneath, have revolute margins and are quite different from those of most other Thalictra in being very strikingly narrow and only occasionally lobed, particularly on the cauline leaves. The terminal leaflet of each division averages 15 mm in length and 7 mm in width on basal leaves, 20.5 mm in length and 4 mm in width on cauline leaves. Of the 58 terminal leaflets from which the above measurements were made, 15 were 3-lobed, 4 were 2-lobed and the remaining 39 were unlobed. The lateral leaflets of each division average 12 mm in length and 6 mm in width on basal leaves, and 16 mm in length and 4 mm in width on the cauline leaves. Of the 111 lateral leaflets measured, 10 were 3-lobed, 11 were 2-lobed and 90 were unlobed. The flowers are borne in an open panicle on pedicels up to 2 cm long. The sepals of staminate flowers, pale yellowish to white in color, are about 1.5 mm long and are very early deciduous. The filaments, slightly clavate, are pale lavender, 2-3 mm long. The lance-oblong anthers are obtuse, 1.5 mm long, and bright yellow. The pistillate flowers are greenish, with smaller sepals and pubescent stigmas, 1.5-2 mm long, as long as or longer than the glabrous ovary. The achenes

STUDIES ON VARIATION IN PATHOGENICITY IN LEAF RUST OF WHEAT, PUCCINIA TRITICINA ERIKSS.

In experiments designed to clarify the causes of the pathogenic changes that have recently been encountered in leaf rust of wheat, two factors were given consideration, (1) the possibility that nuclear exchanges might occur between the mycelia of different races in the uredial stage, and (2) the possible role of Thalictrum species in originating new rust strains. Infection studies with mixtures of races 9 and 15 and mixtures of races 5 and 9 did not produce any evidence that these races could interchange nuclei and thus initiate new pathogenic strains of leaf rust.In greenhouse infection tests with native Thalictrum spp., aecia were produced on T. dasycarpum, pycnia only on T. dioicum and T. polygamum, while no infection of T. venulosum took place. In similar tests with the introduced species T. glaucum and T. dipterocarpum, abundant production of aecia occurred on both species. In out-of-doors inoculation tests with T. dasycarpum and T. venulosum, no infection of these two species took place, whereas, under the same conditions, heavy aecial production occurred on the introduced species T. glaucum.Selfing studies in which Thalictrum glaucum was infected with known physiologic races have indicated that some races of leaf rust are homozygous, and others heterozygous for pathogenic characters. A culture of race 5 appeared to be homozygous, whereas a culture of race 3 was heterozygous, giving rise to races 3, 15, 32, 68, and three undescribed races. A culture of race 76 was heterozygous for both pathogenicity and urediospore color. Aeciospores of this race produced uredia of two different shades of yellow in addition to uredia of normal color. Aeciospores derived from teliospores collected in the field also gave rise to uredial strains of yellow spore color. Most of the yellow rust strains were decidedly low in pathogenic vigor.

Notes on Some Chinese and Korean Species of Thalictrum

Notes on Some Chinese and Korean Species of Thalictrum

Um estudo citológico comparativo de Thalictrum e Ilex

1. New chromosome numbers have been determined tor the following species from material collected in various counties of North Carolina, U . S . A. Thalictrum clavatum n = 7 Th. dioicum n = 14 Th. polygamum n = 42 Th. coriaceum n = 70 Ilex decidua n = 20 I. monticola n = 20 I. vomitoria n = 20 I. opaca n = 18 I. verticillata n = 11. New chromosome numbers have been determined tor the following species from material collected in various counties of North Carolina, U.S.A. Thalictrum clavatum n = 7 Th. dioicum n = 14 Th. polygamum n = 42 Th. coriaceum n = 70 Ilex decidua n = 20 I. monticola n = 20 I. vomitoria n = 20 I. opaca n = 18 I. verticillata n = 18 2. The genus Thalictrum has been rather well investigated cytologically but the genus Ilex has not yet received the attention it merits, and offers cytologists in North, Central, and South America an opportunity ro study an extensive genus which has been, and probably is, undergoing interespecific hybridization while a shift from the hermaphroditic to the unisexual habit is also well established. These two great evolutionary factors, hybridization and the advent of the dioecious condition, appear to stimulate divergent lines of meiotic behavior depending upon whether or not they appear in the phylogeny of a race simultaneously or successively, and in the case of the latter, which came first. The genus Thalictrum was used as a basis for comparison with the situation as found in the eastern North American forms of Hex with the following conclusions. a. The genus Thalictrum is vastly polyploid and meiotically regular. This condition is thought to be the result of previous hybridization of the species before the advent of the dioecious habit. b. The genus Ilex is, as far as research has gone, negatively aneuploid and frequently irregular meiotically. This condition is thought to be the result of previous hybridization of the species after , or no more than simultaneously with, the advent oi the dioecious habit. Heterochromosome Complex Division in first seen Choromatin ejected Other diagnostic hybrid characteristics Species Type of Chromosome I.. decidua Medium Homeotypic One choromatid during second anaphase Laggards anaphase bridges I. monticola. Smallest member of complement Heterotypic One chormatid during first anaphase. Left in cytoplasm Lagging Precocious chorm I. opaca Medium Heterotypic Whole chorm. One chromatid sometimes accepted by complement in second div. Lagging chrom I. verticillata Two types. One tripartite X-- X1Y2 small Other medium Heterotypic Yes. Degenerates during first telophase. Yes Degenerates during first telophase. I. vomitoria Medium sized tripartite complex Heterotypic None found A number of laggards dur-first division 3. Heterochromosomes were found in microsporogenesis of all five species of Ilex, along with other meiotic peculiarities of suggested hybrid origin, but no two were alike. Behavior of the heterochromosomes was not found to be consistent and in approximately 5 0% of the PMCs. meiosis was normal. Findings are summarized in following table.8 4. In view of the generally irabie chromosome number for the five species of Ilex investigated, only such pollen as arises from PMCs. which possess the normal meiosis may produce the gametes which effect fertilization. This presents the problem of explaining how the ability to produce meiotic abnormalities is inherited through cells which dcnot exhibit it or through the female side and its significance on the whole question of the evolution of sex chromosomes from various types of heterochromosomes. 5. A comparison of the cytology or species of Thalictrum and Ilex adds support to the author's earlier contention that so-called sex chromosomes in higher plants have their origin in special types of heterochromosomes which in turn owe their appearance to meiotic disturbances induced by previous hybridization of the species and preserved through the more or less simultaneous advent of the dioecious habit. In the author'- opinion, the genus Ilex offers an opportunity to increase our knowledge of what occur? during the stage intermediate between autosome and the specialized types of sex-linked heterochromosomes.

Sex-Distribution in Thalictrum

DR. ECKHARD KUHN gives an interesting summary of his recent observations upon the occurrence and behaviour of flowers of different sexes in two North American species of Thalictrum in Die Naturwissenschaften of May 12, 1933.