Chromosome numbers of 442 clones of Saccharum spontaneum from various parts of the eastern hemisphere are presented. About 31 numbers ranging from 40 to 128 are so far known to occur in Saccharum spontaneum, of which about nine occur with markedly higher frequencies than the rest. Groups with chromosome numbers which are multiples of eight seem to have a higher survival value than those with others. The distribution area is divisible into three Sectors: the Western with a chromosome number range of 112-128, the Eastern with a range of 80-112, and Central with 40-80. The Central Sector appears to have had a higher evolutionary activity in the species than the other two sectors. The lowest numbers 40 and 48 occur in India, in the Gangetic valley sub-montane to the Central Himalayas, and also in the four south-eastern deltaic areas, Since the area encompassing the locations of low chromosome number groups has also the largest concentration of chromosome numbers, it is of cytogeographic interest. The 54-chromosome group is believed to extend along various river basins from the Aral Sea to the Bay of Bengal. The 64-group is somewhat ubiquitous in India, dominant in the peninsula; Central India has mostly 62 to 72-chromosome clones to the exclusion of other numbers. The 80-chromosome forms occur restrictedly in Nepal, Assam and the Western Ghats. The number 112 occurs both in the Western and Eastern Sectors, but the two groups are probably distinct. 80 and 96 are conspicuously absent from the area between India and Africa. The forms of the Western Sector have many distinctive characters in common. They are probably of autopolyploid origin. In the Eastern Sector, the typical numbers are 80, 96 and 112. In most of the areas, 80 and/or 96 occur to the exclusion of other major numbers, whereas Java, Sumatra and Borneo have almost exclusively 112-chromosome forms. The 80-chromosome forms form a continuous chain from Nepal to Fiji, by-passing the major part of Indonesia. 64-chromosomes occur exceptionally in Burma, Malay and Mauritius. These are believed to be accidental introductions from India. By analogy, the presence of the 112-chromosome forms in the China-Japan area may be attributed to Chinese trade activity with Indonesia.
1. The male diploid chromosome complement of B. caeruleus shows 44 chromosomes which consist of 2 V-shaped, 22 rod-shaped and 20 dotshaped elements. 2. The fundamental chromosome number is 46. 3. This karyotype differs markedly from the karyotype of B. multicinctus described by Nakamura (1935). 4. Meiosis is normal and the male is the homogametic sex.
1. The cytology of Polygonatum Miller, Disporum Salisb. ex D. Don, and Smilacina Desf., the three common genera of the tribe Polygonateae occurring in the Western Himalayas, has been worked out. 2. Polygonatum multiflorum All. has 2n=22 and n=11 chromosomes. The karyotype is symmetrical and agrees in certain respects with that of the European P. multiflorum worked out by Therman which has 2n=18. 3. Polygonatum verticillatum All. has 2n=66 chromosomes, differing from the numbers previously reported for the species. The karyotype is of the symmetrical type. Meiosis is highly irregular. It is suggested to be an autoallopolyploid. 4. Polygonatum sibiricum Red. (=P. cirrhifolium Royle) has 2n=36 and n=18 chromosomes. The karyotype is highly asymmetrical. 5. In the Polygonatums studied the numbers are new records not only for the species concerned but also for the genus. 6. Disporum cantoniense (Lour.) Merr. (=D. pullum Salisb.) has 2n=16 chromosomes. Its karyotype is different from the Japanese form which however has the same chromosome number. 7. Smilacina purpurea Wall. (=S. pallida Royle) has n=18 chromosomes.
1. The eleven wild species of Vigna studied can be classified into four groups on the basis of their morphological affinities. i) In the first group comprising of the species viz. V. parviflora Welw., V. wilmsii Burtt Davy., V. oblongifolia A. Rich., and V. gracilis Hook. flowers are small zygomorphic, keel and style are not twisted, the posterior two sepals are fused and seeds are small oblong with caruncle. ii) The second group consisting of the three species viz. V. luteola Benth., V. marina (Burm) Merr. and V. schimperi Baker differs from the first group in having larger flowers and reniform seeds without caruncle. iii) The plants of the third group consisting of the species V. vexillata (Linn.) Benth. and V. davyi Bolus. have conspicuously large irregular flowers in which the posterior two sepals are not fused, keel slightly twisted with one sided pouch, style slightly twisted tuberous root and seeds reniform without caruncle. iv) V. membranacea A. Rich. is the lone member of the fourth group having several common features of both the second and third groups. 2. The plants of the third group in having slightly twisted keel with one sided pouch also show their affinity to the genus Phaseolus. 3. The karyotypic study of the Vigna species has shown the presence of two chromosome numbers 2n=22 and 2n=20. V. parviflora, V. wilmsii, V. oblongifolia, V. gracilis, V. sehimperi, V. luleola, V. marina, V. vexillata and V. davyi and the cultivated species V. catjang, V. sinensis and V. sesquipedalis have 2n=22 chromosomes. Only two species viz. V. heterophylla and V. membranacea have 2n=20 chromosomes. 4. The chromosome number 2n=24 reported for V. catjang, V. sinensis and V. sesquipedalis by some workers has not been observed in any of the six varieties, two from each group, studied. 5. The chromosome complements of the fourteen species are more or less similar in the number of long, medium and short chromosomes and in their gross morphology. 6. The chromosmes of all the species are very small, ranging from 1.6 to 3.7μ in length and have submedian primary constriction. Long chromosomes in the different species vary from 3.0 to 3.7μ and the short chromosomes from 1.6 to 2.0μ. 7. Meiotic studies have shown regular pairing of the homologous chromosomes forming bivalents in diakinesis and metaphase, and normal subsequent meiotic stages. 8. The possibility of eleven as the basic chromosome number of Vigna has been indicated. It has been assumed that the 2n=20 chromosomes type V. heterophylla has been derived from the first group of species and the V. membranacea from a 2n=22 chromosome group intermediate between the second and the third groups. 9. The three cultivated types V. catjang, V. sinensis and V. sesquipedalis need not be considered as distinct species but should be regarded as members of a polymorphic species, V. sinensis with three subspecies viz, V. sinensis, V. sinensis subspecies catjang and V. sinensis subspecies sesquipedalis. 10. They resemble the plants of the second group and are likely to have been derived from them. V. luteola of that group is most closely related to the cultivated species and is the only species that gave a few pods in crosses with them. It seems that V. catjang and V. sinensis have been gradually differentiated from a common ancestral stock and V. sesquipedalis is a later selection from V. sinensis.
1. In the present research, karyogenetical studies on the F1plant raised from T. turgidum (n=14)×H. hordeacea (n=7) were carried out. 2. In general, the external characteristics of the F1 plant resembled the parents, but very closely resembled H. hordeacea, the pollen plant (Figs. 12). 3. The somatic number of chromosomes of the F1 plant was 28. This number has 7 in excess to the usual number which corresponds to the sum of the gametic numbers of both parents, viz., 14+7=21. The surplus 7 chromosomes may have been derived from duplication of the 7 chromosomes of H. hordeacea, the pollen plant. 4. At the heterotypic metaphase in meiosis of PMC's of the F1 plant, 512 bivalents or 418 univalents were observed (Table 4). 6 or 7 of the 12 bivalents might have been formed by the autosyndesis among the chromosomes of H. hordeacea, and the remaining 5 or 6 bivalents probably were made by autosyndesis between the chromosomes of AB genomes of T. turgidum. 5. The F1 plant shows to be completely sterile in natural selfing, however, it is perennial.
1. In der vorliegenden Arbeit wurden die 3 Spezies der Oxymitra-, Corsinia- und Lunulariaceae untersucht, um these neuen 3 Familien der Marchantiales zu meinen vorhergehenden karyologischen Untersuchungen der Marchantiales (1956, 1957) hinzuzufügen. Ebenso wurden auch 3 Asterella-Arten der Rebouliaceae karyologisch studiert. 2. Unter den untersuchten 6 Arten haben 4, nämlich Oxymitra paleacea, Asterella Lindenbergiana, A. Stahlii und Lunularia cruciata, übereinstimmend die Chromosomenzahl n=9: 4V, 4J und ein m. Die anderen beiden Arten: Corsinia coriandrina und Asterella Ludwigii, sind diploid mit n=18: 8V, 8J and 2m, und zwar wurde die Chromosomenzahl dieser beiden diploiden Arten von mir zuerst festgestellt. 3. Die h-Chromosomen, die sich bei allen untersuchten Arten befinden, sowie die Satelliten-Chromosomen von Oxymitra paleacea sind immer Nukleolinus-Chromosomen, weil ein heterochromatischer Schenkel der h und der heterochromatische Satellit der Satelliten-Chromosomen die Nukleolini in den Nukleolen bilden. 4. Die h-Chromosomen von Oxymitra paleacea und Corsinia coriandrina weisen in der Metaphase die negative Heterochromasie auf. 5. Im allgemeinen kommt die Heterochromasie der Chromosomen der Marchantiales bei den folgenden sechs Einheiten vor, beim H-, h- and Jt, ebenso bei der 3V-, 4J- und der 3J-Gruppe. Die Arten, die phylogenetisch als höhere anzusehen sind, haben mehr heterochromatische Einheiten als die primitiven. Diese gleitende Entwicklung der Heterochromasie dürfte darauf hindeuten, daß das bestimmte euchromatische Segment des Chromosoms der primitiven Arten mit der Entwicklung der Moose zusammengeht, und sich durch das Heterochromatin ersetzen läßt.
In this report, is presented a new method for the microscopic observation of colored particles in tissues or cells, in which opal glass is placed in a position directly under a slide glass to illuminate a sample with completely diffuse light. It was demonstrated that, under diffuse-light illumination, we have practically no image due to the difference of refractive index such as those of colorless boundaries, so that we can observe only the images of colored particles with no interference of the images of the boundaries. Furthermore, the images of colored particles are sharply defined with no deformation under diffuse-light illumination, whereas they are obscure and more or less deformed under normal illumination. The principle of the new technique is described together with the characteristics in the microscopic observations of colored particles.
Eleven species of Collinsia Nutt. (Scrophulariaceae) have been involved in interspecific hybridizations. Data were presented on the yield of germinating seed from these hybridizations, on the mean number of chiasmata at metaphase I, on chromosome associations at metaphase I, on the number of detectable, heterozygous paracentric inversions, and on the fertility of the interspecific hybrids. Many hybrids had one or two interchange complexes at metaphase I, involving four, six, eight, or ten chromosomes. It was possible to construct a scheme for the organization of the chromosomes of ten species which was consistent with the observations on the chromosome associations at metaphase I in the hybrids. The genomes of the ten species appear to be homologous but have undergone extensive repatterning. The fertility or sterility of certain interspecific hybrids was related to the presence of chromosome aberrations. Extensive repatterning of the chromosomes appears to have been a major factor in speciation; polyploidy has played a minor role.
C57 black male mice about 100 days of age were exposed to elevated temperature of 35°C and 70% humidity in four exposure periods totaling 61 hours distributed over 4 days. Animals were sacrificed at 3, 5, 7 and 10 days after the end of the heat treatment. Results of the heat treatment were compared with those following 1000 r X-irradiation. The damage inflicted on the mouse testis by this heat treatment differed fundamentally from that induced by 1000 r acute localized X-irradiation. Comparison at 10 days after treatment was especially revealing. Elevated temperature induced the formation of giant cells, originating either, from karyokinesis without cytokinesis or from agglomeration. The latter condition was most predominant when spermatozoal heads with indistinct tails were involved. No giant cells were seen after X-irradiation. Spermatogonia survived the heat treatment so that after 10 days, recovery was in full swing. X-Rays killed spermatogonia with the exception of occasional type A cells. Recovery had not started after 10 days. Late spermatocytes became pycnotic as a result of heat treatment; of these, some regressed, and a few underwent restitution or C-division. Normal spermatids were not formed. Late spermatocytes were blocked by 1000 r X-irradiation; the block was so persistent and so severe that 76% of the tubular cross sections seen at 10 days contained some form of restituted or regressed spermatocytes. Ten days after heat treatment no restituted or regressed spermatocytes were seen. This may be related to the fact that heat seems to be less damaging than X-rays to the emptying mechanism of tubules. Spermatids appear equally damaged by heat and by X-rays. Spermatozoal heads are more common at 10 days after X-rays than after heat treatment; this may result from the lesser effect of heat on the emptying mechanism as well as from a qualitative difference in the damage inflicted.
1. Diploidy is the prevailing chromosomal complement in parthenogenetically developing turkey germ discs and embryos. 2. The modal chromosomal count in normal turkey embryonic material is 72. On the basis of their size the chromosomes can be classified into macro-chromosomes and micro-chromosomes. The former can be further subdivided into two subgroups: (a) the largest eight are very conspicuous both in shape and size (because of this they have been used as markers in this study for ascertaining ploidy in the parthenogenetic material); (b) about ten middle-sized chromosomes. There are approximately 54 micro-chromosomes, with the number varying among the individual embryonic specimens, and within cells of the same specimen. 3. The available parthenogenetic material has demonstrated the presence of two small, V-shaped chromosomes in the metaphase nuclear plates. These chromosomes were classed as sex chromosomes because of sex dimorphism in their number. On the basis of this, the genetic sex of the membranous growths and of embryos was determined to be male. 4. In addition to normal diploid cells, the parthenogenetic specimens showed numerous polyploid (mostly tetraploid) plates. These were interpreted to be the product of the restitution nuclei fused into one, or of mitotic divisions in the binucleated cells. 5. Small nuclear plates, interpreted to possess the haploid chromosomal complement, also occurred frequently in the parthenogenetic material. The occurrence of such plates may be a major factor responsible (either per se or due to recessive lethals) for the abortive nature of most of the instances of parthenogenetic development in turkeys.
In the present investigation, the interrelation of the thread-like apparatus and the chloroplasts in the lacunal parenchyma of Mimosa petiole were studied from the cytophysiological view point. The experimental results obtained are summarized below. 1) Thread-like apparatus and chloroplasts in the lacunal parenchymatous cells of petiole are chiefly dealt with. 2) By Champy-Toriyama's method, the tannin vacuoles in the tissue-cells at diurnal condition were observed to be more inflated than those in nocturnal condition. Such a difference was also observable in the fresh material. 3) In the fresh material, thread-like apparatus in the diurnal condition are thicker than those in the nocturnal period. By Champy-Toriyama's method, the threads have a tendency to be fixed as a bead-like feature in the diurnal condition. On the contrary, in the nocturnal period, the threads appear having thin slender features. 4) Under the direct sunshine in August, the small black granules appear in the chloroplast in material treated with Champy's fluid. On the contrary, in the nocturnal condition, these granules do not appear in the chloroplast. 5) The morphological features of the thread-like apparatus are affected by artificial light and sugar solution. 6) By vital staining, many features of the threads which keep connection with chloroplasts are observable. 7) From the topographical relationship between these two elements and from the data of these experiments, it is probable that the thread-like apparatus play some rôle in carbohydrate metabolism. 8) A part of the thread is capable of transforming by shortening and becoming thicker in fresh material.
The damage to tumor cells following the application of Mitomycin C was studied from the viewpoints of cytology and cytochemistry in the MTK-sarcoma III of rats and EM tumor of mice. Cytological observations revealed the occurrence of abnormal mitotic figures of various types in affected tumor cells. The application of certain cytochemical methods has made it clear that the main effects of Mitomycin C is to damage the DNA in the resting nucleus and some influence to change the nature of the RNA in the nucleolus. It is apparent that these cytochemical changes may induce abnormal division in affected tumor cells.