1939 205
Studies on the Chromosome Numbers in Higher Plants III* By T. Sugiura Osaka Higher School, Osaka
Received January 27, 1939 Materials Materials used here were 42 species belonging to 22 families, raised from seeds. Some of them were sent from the chief botanical gardens in Europe, to the authorities of which the writer wishes to express his best thanks. The technique used in this work has been referred to in previous papers.
The Mode of Cell Division in PMC The plants described below all show the furrowing process in the mode of the partition wall formation of the pollen mother cells (cf. Sugiura 1936b).
Numbers of Chromosomes Compositae: Cosmos sulphureus, C. diversifolius. The numbers of chromosomes formerly found in Coreopsidinae were in Bidens 12, 24, in Coreopsis 12, and in Dahlia 16, but none in Cosmos. The writer formerly counted 24 somatic chromosomes in C. bipinnatus (1931). Now he has also counted 12 meiotic chromo somes in each of the above two species. The diversifolius species has somewhat larger meiotic chromo somes than those of the sulphureus at the same stage, although the outer appearance of the former was much smaller. As there is no secondary pairing of chromosomes to be seen in the meiotic division in these species, the basic number of chromosomes in Cosmos is probably 12. Campanulaceae (Lobelioideae): Lobelia Cliffortiana, L. inflata, L. Richardsonii, L. tenuior. The reported chromosome numbers in the genus Lobelia are shown in the Table 1.
* The studies were made under the subsidy from the Japan Society for the Promotion of Scientific Research. 206 T. SUGIURA Cytologia 10
Table 1
The writer having already counted the meiotic numbers of chromosomes in three species, now studied the above four species , fi nding 7,7 and 8, 9 and 21 meiotic chromosomes . It was very interesting to find these two meiotic numbers in L . inflata, namely 7 and 8. The latter number 8 has already been noticed '37) . (Sugiura . In the second metaphasic figures there are 8, almost equal, chromosomes and 7, one of which a little larger , chromosomes in the same anther. It may be conjectured that L. erinus, wrens and Dortmanna may also have 8 chromosomes in addition to the normal 7 ones , j udging from the above and from the results of Armand's investiga tion. In this case the 7 chromosome group is probably derived from the 8 chromosome group by fusing two of them . Multiple numbers of 8 and 9 have not been found yet , although those of 7 have already been found, namely 14 and 21. Thus we now conclude that 8 is the basic chromosome number in Lobelia and 7 and 9 are derived from it. Dowwningia pulchella. The genus Downingia has not been studied karyologically yet. There are 11 meiotic chromosomes , one of which is very large like a nucleolus .
Rubiaceae: Crucianella stylosa . The meiotic chromosome numbers in the genus Crucianella were ascertained by Lloyd (1920) to be about 10 in C . macrostachya and gilanica, by Fagerlind and Homeyer (1932, 34) to be 11 and 22 in other species. Thus there are two different basic numbers i n the genus, namely 10 and 11. We now know that the meiotic number of chromosomes in C . 1939 Studies on the chromosome numbers in higher plants III 207
stylosa is 11 and the former count should be corrected. Quite recent ly Fagerlind has counted 11 meiotic chromosomes in 9 species of
Crucianella and 22 in another.
Acanthaceae: Acanthus spinosus, Dicliptera resupinata, Ruellia
amoena, R. dipteracanthus.
The writer previously counted 28 meiotic chromosomes in A. lusitanicus and has now found 56 in A. spinosus. It is interesting to note that the outer appearances of A. spinosa is very much smaller than that of A. lusitanicus in spite of the fact that the chromosome number of the former is twice that of the latter. The pollen mother cells are very large, measuring about 21.5ƒÊ in diameter.
Dicliptera resupinata. This has 20 meiotic chromosomes. The
pollen mother cells are about 15ƒÊ in diameter. Ruellia amoena R. dipteracanthus. These two Ruelliae both
have 18 meiotic chromosomes. Combining the results of my former count with the present results, we now know that there are 16 and 18 meiotic chromosomes in Ruellia. Putting together these studies
on Acanthus, Ruellia, Thunbergia etc., we are able to say that pollen
mother cells of Acanthaceae are much larger than those of other families, while the chromosomes they contain are much smaller in comparison.
scrophulariaceae: Hebenstreitia dentata. Hebenstreitia belonging to Selagineae, has not been investigated karyologically yet. Formerly the writer found 7 meiotic chromo somes in H. comosa and recently also found the same number of chromosomes in dentata.
Loganiaceae: Buddlea asiatica, B. eurviflora var. venenifera. So far as the writer knows, the chromosome numbers in this family have not been ascertained. The present karyological investi gation shows that the meiotic chromosome numbers in these species are all 15.
Primulaceae: Lysimachia clethroides. Lewitsky has counted 24 somatic chromosomes in Lysimachia vulgaris, 34-36 in L. nummularia. The meiotic chromosomes counted here in the above species are 12. Quite recently Wulff counted 9 meiotic chromosomes in L. nemorum.
Dispensiaceae: Dispensia obovata. Hagerup (1928) counted 6 meiotic chromosomes in D. lap ponica. The writer also found the same number in this species. 208 T. SUGIURA Cytologia 10
Figs. 1-38. •~3330. 1, Cosmos sulphureus. IM. 2, C. diversiculatum. IM. 3, Lobelia Cliffortiana. IIM. 4 a, b, L. inflata. IIM. 5, L. Richardsonii. IIM. 6, L. tenuior. IIM. 7, Downingia pulchella. IA. 8, Crucianella stylosa. IIM. 9, Acanthus spinosus. IM. 10, Dicliptera resupinata. IIM. 11, Ruellia amoena. IIM. 12, R. dipteracanthus. IA. 13, Hebenstreitia dentata. IA. 14, Buddlea asiatica. IM. 15, Lysimachia clethroides. IIM. 16, Dispensia obovata. IIM. 17, Cuphea cyavea. IM. 1939 Studies on the chromosome numbers in higher plants III 209
The second meiotic chromosomes are rod-shaped. The pollen mother cells are large in comparison with external appearances.
Lythraceae: Cuphea cyanea, C. petiolata, C. lanceolata. So far as I am aware, the only chromosome numbers known in this family are those of the genus Lythrum. Former studies showed that the meiotic chromosome numbers in the Lythrum species were multiples of five. In spite of that, Cuphea and Lythrum belong to the same section the Lythreae, the meiotic number of chromosomes, of the former differing from that of -the latter, the former being 6 while the latter 5, although multiples of 5 are only found. The same thing was also found in Heitz's Antirrhinum and also in my studies on Armeria and Statice etc.
Loasaceae: Loasa hispi ia, L. triphylla, L. vulcanica. Formerly the writer counted 12 meiotic chromosomes in the pollen mother cells of L. aurantiaca. Three other species were examined, but these have different numbers of meiotic chromosomes; the former has 15, while the latter two has 14 each. Among the meiotic chromosomes of the Loasa, those of L. triphylla were the largest of all.
Frankeniaceae: Frankenia pulverulenta. So far as I know there has been no karyological description of this family. The pollen mother cells are large in comparison with external appearances. There are found 10 meiotic chromosomes.
Guttiterae: Hypericum polyphyllum. Nielson (1924) counted 9 meiotic chromosomes in this plant which has been confirmed by the writer. In the pollen mother cell it was found that the first meiotic chromosomes were spherical while the second ones slender and rod-shaped like those of the somatic cells. The chromosome numbers hitherto counted in this genus are 7, 8, 9, 10, 16, 18 and 20 (cf. Winge 1925, Chattaway 1926).
18, C. petiolata. IIM. 19, C. lanceolata. IA. 20, Loasa hispida. IM. 21. L. tri phylla. IM. 22, L. vulcanica. IM. 23, Frankenia pulverulenta. IM. 24, Hypericum polyphyllum. IIM. 25, Limnanthes albs. IM. 26, Cleome trachysperma. IA. 27, Cimicifuga a.cerina var. obtusiloba. IA. 28, Lychnis chalcedonicia. IIM. 29, Corri giola littoralis. IIM. 30, Delosperma herbeum. IIM. 31, D. Steytlerae. IA. 32, Mesembrianthemum multiflorum. IIM. 33, Emex spinosa. IM. 34, Phytolacca octan dra. IIM. 35, Ph. sessiliflora. IIM. 36, Petiveria alliacea. IIM. 37, Cymbidium sinense. IM. 38, Aerides japonicum. IM.
Cytologia10. 1939 14 210 T. SUGIURA Cytologia 10
I believe that 4 is the probable basic number in this genus as Winge stated (1925). Limnanthaceae: Limnanthes alba. The writer previously counted 5 meiotic chromosomes in L. Douglasii, and recently also found the same number in the above species. Their size and shape are very similar to those of the former.
Capparidaceae: Cleome trachysperma. It has 10 meiotic chromosomes. As to the chromosome numbers in the genus Cleome it has been known that they vary; viz. 10, 11, 12, 16, 19, 70, and 140. Even in the same species, for example, C. spinosa, three numbers have been found, 10, 12, and 19. As it is, the basic number cannot be determined at present. Ranunculaceae: Cimicifuga acerina var. obtusiloba. The genus Cirmm.icifuga has been studied karyologically by Lewitsky, Nakajima and Langlet. These writers, however, have only studied somatic chromosomes, their counts being 16. The writer studying the pollen mother cells, found 8 chromosomes which were as large as those of Adonis (Sugiura 1936).
Caryophyllaceae: Lichnis chalcedonica. Blackburn (1928) and Sokolowa (1931) have studied this and counted 12 meiotic chromosomes. My own count was the same. The second meiotic chromosomes are V shaped. Corrigiola littoralis. Rocen (1927) counted about 8 meiotic chromosomes in this species and Blackburn (1934) 18 somatic. The writer, however, has counted 8 meiotic ones which are very small together with the pollen mother cells. Aizoaceae: Delosperma herbeum, P. multiflorum, P. Steytlerae. There have been no karyological studies on the genus Delo sperm.a yet. They have 9 spherical chromosomes each. The meiotic chromo somes are generally much smaller than those of Mesembryanthemum.
Polygonaceae: Em.e.r spinosa. This plant has been already studied by Jaretzky (1927) and Edman (1929), both having counted 10 meiotic chromosomes. The writer's count was the same.
Phytoiaccaceae: Phytolacca octandra, P. sessiliflora. We have studied the above two plants and found 18 meiotic chromosomes in the former and 9 in the latter. The latter plant 1939 Studies on the chromosome numbers in higher plants III 211
Table 2
14* 212 T. SUGIURA Cytologia 10
being as tall as P acinosa, the meiotic chromosomes are twice as
large as the former, the epidermal cells of the leaves in the latter
are also larger than those of Phytolacca decandra (n=18). The basic chromosome number in the genus Phytolacca has therefore
been definitely determined to be 9. Petiveria alliacea. There have been no karyological studies on
this genus. The meiotic chromosomes, being 36 in number, are rather big in spite of the large number of chromosomes.
Orchidaceae: Cymbidium sinense.
Suessenguth (1920) counted 9-10 meiotic chromosomes in C. Lowianum but afterwards Hoffmann (1920-30) found 20 in the
same plant.
Aerides japonicum. No karyological descriptions of the chro mosome numbers are known for Aerides. We have now found 19
meiotic chromosomes in this species, while Sarcanthus rostratus,
belonging also to the Sarcantheae, has 18 meiotic chromosomes.
The results of the present investigation are summarized in
Table 2.
Literature
Okuno, ., 1937, Karyological Studies on Some Species of Lobelia. Cytologia (Fujii Jub. Vol.) Sugiura, T., 1936, Studies on the Chromosome Numbers in Higher Plants with Special Reference to Cytokinesis, I. Cytologia 7. - 1937, Do. II. Cytologia (Fujii Jub. Vol.) - 1937, A List of Chromosome Numbers in Angiospermous Plants, III. Bot. Mag. (Tokyo), 51. Tischler, G., 1927, Pflanzliche Chromosomenzahlen. Tab. Biol. 4. - 1931, •V (Nachtrag Nr. 1.) •V 7. - 1936, •V (Nachtrag Nr. 2.) •V 12. - 1938, .. •V (Nachtrag Nr. 3.) •V 16. Winge, O., 1925, Contributions to the knowledge of the chromosome numbers of plants. La Cellule 35.