Resumo
1) The first part deals with the different processes which may complicate Mendelian segregation and which may be classified into three groups, according to BRIEGER (1937b) : a) Instability of genes, b) Abnormal segregation due to distur- bances during the meiotic divisions, c) obscured segregation, after a perfectly normal meiosis, caused by elimination or during the gonophase (gametophyte in higher plants), or during zygophase (sporophyte). Without entering into detail, it is emphasized that all the above mentioned complications in the segregation of some genes may be caused by the action of other genes. Thus in maize, the instability of the Al factor is observed only when the gene dt is presente in the homozygous conditions (RHOADES 1938). In another case, still under observation in Piracicaba, an instability is observed in Mirabilis with regard to two pairs of alleles both controlling flower color. Several cases are known, especially in corn, where recessive genes, when homozigous, affect the course of meiosis, causing asynapsis (asyndesis) (BEADLE AND MC CLINTOCK 1928, BEADLE 1930), sticky chromosomes (BEADLE 1932), supermunmerary divisions (BEADLE 1931). The most extreme case of an obscured segregatiou is represented by the action of the S factors in self stetrile plants. An additional proof of EAST AND MANGELSDORF (1925) genetic formula of self sterility has been contributed by the studies on Jinked factors in Nicotina (BRIEGER AND MANGELSDORF (1926) and Antirrhinum (BRIEGER 1930, 1935), In cases of a incomplete competition and selection between pollen tubes, studies of linked indicator-genes are indispensable in the genetic analysis, since it is impossible to analyse the factors for gametophyte competition by direct aproach. 2) The flower structure of corn is explained, and stated that the particularites of floral biology make maize an excellent object for the study of gametophyte factors. Since only one pollen tube per ovule may accomplish fertilization, the competition is always extremely strong, as compared with other species possessing multi-ovulate ovaries. The lenght of the silk permitts the study of pollen tube competitions over a varying distance. Finally the genetic analysis of grains characters (endosperm and aleoron) simpliflen the experimental work considerably, by allowing the accumulation of large numbers for statistical treatment. 3) The four methods for analyzing the naturing of pollen tube competition are discussed, following BRIEGER (1930). Of these the first three are: a) polinization with a small number of pollen grains, b) polinization at different times and c) cut- ting the style after the faster tubes have passe dand before the slower tubes have reached the point where the stigma will be cut. d) The fourth method, alteration of the distatice over which competition takes place, has been applied largely in corn. The basic conceptions underlying this process, are illustrated in Fig. 3. While BRINK (1925) and MANGELSDORF (1929) applied pollen at different levels on the silks, the remaining authors (JONES, 1922, MANGELSDORF 1929, BRIEGER, at al. 1938) have used a different process. The pollen was applied as usual, after removing the main part of the silks, but the ears were divided transversally into halves or quarters before counting. The experiments showed generally an increase in the intensity of competition when there was increase of the distance over which they had to travel. Only MANGELSDORF found an interesting exception. When the distance became extreme, the initially slower tubes seemed to become finally the faster ones. 4) Methods of genetic and statistical analysis are discussed, following chiefly BRIEGER (1937a and 1937b). A formula is given to determine the intensity of ellimination in three point experiments. 5) The few facts are cited which give some indication about the physiological mechanism of gametophyte competition. They are four in number a) the growth rate depends-only on the action of gametophyte factors; b) there is an interaction between the conductive tissue of the stigma or style and the pollen tubes, mainly in self-sterile plants; c) after self-pollination necrosis starts in the tissue of the stigma, in some orchids after F. MÜLLER (1867); d) in pollon mixtures there is an inhibitory interaction between two types of pollen and the female tissue; Gossypium according to BALLS (1911), KEARNEY 1923, 1928, KEARNEY AND HARRISON (1924). A more complete discussion is found in BRIEGER 1930). 6) A list of the gametophyte factors so far localized in corn is given. CHROMOSOME IV Ga 1 : MANGELSDORF AND JONES (1925), EMERSON 1934). Ga 4 : BRIEGER (1945b). Sp 1 : MANGELSDORF (1931), SINGLETON AND MANGELSDORF (1940), BRIEGER (1945a). CHROMOSOME V Ga 2 : BRIEGER (1937a). CHROMOSOME VI BRIEGER, TIDBURY AND TSENG (1938) found indications of a gametophyte factor altering the segregation of yellow endosperm y1. CHROMOSOME IX Ga 3 : BRIEGER, TIDBURY AND TSENG (1938). While the competition in these six cases is essentially determined by one pair of factors, the degree of elimination may be variable, as shown for Ga2 (BRIEGER, 1937), for Ga4 (BRIEGER 1945a) and for Spl (SINGLETON AND MANGELSDORF 1940, BRIEGER 1945b). The action of a gametophyte factor altering the segregation of waxy (perhaps Ga3) is increased by the presence of the sul factor which thus acts as a modifier (BRINCK AND BURNHAM 1927). A polyfactorial case of gametophyte competition has been found by JONES (1922) and analysed by DEMEREC (1929) in rice pop corn which rejects the pollen tubes of other types of corn. Preference for selfing or for brothers-sister mating and partial elimination of other pollen tubes has been described by BRIEGER (1936). 7) HARLAND'S (1943) very ingenious idea is discussed to use pollen tube factors in applied genetics in order to build up an obstacle to natural crossing as a consequence of the rapid pollen tube growth after selfing. Unfortunately, HARLAND could not obtain the experimental proof of the praticability of his idea, during his experiments on selection for minor modifiers for pollen tube grouth in cotton. In maize it should be possible to employ gametophyte factors to build up lines with preference for crossing, though the method should hardly be of any practical advantage.
A ação dos gens gametofíticos com referência especial ao milho
F. G. Brieger
Escola Superior de Agricultura "Luiz de Queiroz", Universidade de S. Paulo
ABSTRACT
1) The first part deals with the different processes which may complicate Mendelian segregation and which may be classified into three groups, according to BRIEGER (1937b) : a) Instability of genes, b) Abnormal segregation due to distur- bances during the meiotic divisions, c) obscured segregation, after a perfectly normal meiosis, caused by elimination or during the gonophase (gametophyte in higher plants), or during zygophase (sporophyte).
Without entering into detail, it is emphasized that all the above mentioned complications in the segregation of some genes may be caused by the action of other genes. Thus in maize, the instability of the Al factor is observed only when the gene dt is presente in the homozygous conditions (RHOADES 1938). In another case, still under observation in Piracicaba, an instability is observed in Mirabilis with regard to two pairs of alleles both controlling flower color.
Several cases are known, especially in corn, where recessive genes, when homozigous, affect the course of meiosis, causing asynapsis (asyndesis) (BEADLE AND MC CLINTOCK 1928, BEADLE 1930), sticky chromosomes (BEADLE 1932), supermunmerary divisions (BEADLE 1931).
The most extreme case of an obscured segregatiou is represented by the action of the S factors in self stetrile plants. An additional proof of EAST AND MANGELSDORF (1925) genetic formula of self sterility has been contributed by the studies on Jinked factors in Nicotina (BRIEGER AND MANGELSDORF (1926) and Antirrhinum (BRIEGER 1930, 1935), In cases of a incomplete competition and selection between pollen tubes, studies of linked indicator-genes are indispensable in the genetic analysis, since it is impossible to analyse the factors for gametophyte competition by direct aproach.
2) The flower structure of corn is explained, and stated that the particularites of floral biology make maize an excellent object for the study of gametophyte factors. Since only one pollen tube per ovule may accomplish fertilization, the competition is always extremely strong, as compared with other species possessing multi-ovulate ovaries. The lenght of the silk permitts the study of pollen tube competitions over a varying distance. Finally the genetic analysis of grains characters (endosperm and aleoron) simpliflen the experimental work considerably, by allowing the accumulation of large numbers for statistical treatment.
3) The four methods for analyzing the naturing of pollen tube competition are discussed, following BRIEGER (1930). Of these the first three are: a) polinization with a small number of pollen grains, b) polinization at different times and c) cut- ting the style after the faster tubes have passe dand before the slower tubes have reached the point where the stigma will be cut. d) The fourth method, alteration of the distatice over which competition takes place, has been applied largely in corn. The basic conceptions underlying this process, are illustrated in Fig. 3. While BRINK (1925) and MANGELSDORF (1929) applied pollen at different levels on the silks, the remaining authors (JONES, 1922, MANGELSDORF 1929, BRIEGER, at al. 1938) have used a different process. The pollen was applied as usual, after removing the main part of the silks, but the ears were divided transversally into halves or quarters before counting. The experiments showed generally an increase in the intensity of competition when there was increase of the distance over which they had to travel. Only MANGELSDORF found an interesting exception. When the distance became extreme, the initially slower tubes seemed to become finally the faster ones.
4) Methods of genetic and statistical analysis are discussed, following chiefly BRIEGER (1937a and 1937b). A formula is given to determine the intensity of ellimination in three point experiments.
5) The few facts are cited which give some indication about the physiological mechanism of gametophyte competition. They are four in number a) the growth rate depends-only on the action of gametophyte factors; b) there is an interaction between the conductive tissue of the stigma or style and the pollen tubes, mainly in self-sterile plants; c) after self-pollination necrosis starts in the tissue of the stigma, in some orchids after F. MÜLLER (1867); d) in pollon mixtures there is an inhibitory interaction between two types of pollen and the female tissue; Gossypium according to BALLS (1911), KEARNEY 1923, 1928, KEARNEY AND HARRISON (1924). A more complete discussion is found in BRIEGER 1930).
6) A list of the gametophyte factors so far localized in corn is given.
CHROMOSOME IV
Ga 1 : MANGELSDORF AND JONES (1925), EMERSON 1934).
Ga 4 : BRIEGER (1945b).
Sp 1 : MANGELSDORF (1931), SINGLETON AND MANGELSDORF (1940), BRIEGER (1945a).
CHROMOSOME V Ga 2 : BRIEGER (1937a).
CHROMOSOME VI
BRIEGER, TIDBURY AND TSENG (1938) found indications of a gametophyte factor altering the segregation of yellow endosperm y1.
CHROMOSOME IX Ga 3 : BRIEGER, TIDBURY AND TSENG (1938).
While the competition in these six cases is essentially determined by one pair of factors, the degree of elimination may be variable, as shown for Ga2 (BRIEGER, 1937), for Ga4 (BRIEGER 1945a) and for Spl (SINGLETON AND MANGELSDORF 1940, BRIEGER 1945b). The action of a gametophyte factor altering the segregation of waxy (perhaps Ga3) is increased by the presence of the sul factor which thus acts as a modifier (BRINCK AND BURNHAM 1927).
A polyfactorial case of gametophyte competition has been found by JONES (1922) and analysed by DEMEREC (1929) in rice pop corn which rejects the pollen tubes of other types of corn. Preference for selfing or for brothers-sister mating and partial elimination of other pollen tubes has been described by BRIEGER (1936).
7) HARLAND'S (1943) very ingenious idea is discussed to use pollen tube factors in applied genetics in order to build up an obstacle to natural crossing as a consequence of the rapid pollen tube growth after selfing. Unfortunately, HARLAND could not obtain the experimental proof of the praticability of his idea, during his experiments on selection for minor modifiers for pollen tube grouth in cotton. In maize it should be possible to employ gametophyte factors to build up lines with preference for crossing, though the method should hardly be of any practical advantage.
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LITERATURA
1 - BALLS, w. L. 1911 - Cotton investigations in 1909 and 1910. Cairo Sci. J. 5.
2 - BEADLE, G. W. 1931 - A gene in maize for supernu- merary cell divisions following meiosis. Cornell Univ. Exp. Sta. Mem. 135: 12 pgs.
3 - BEADLE, G. W. 1930 - Genetical and cytological studies of Mendelian asynapsis in Zea Mays. Cornell Univ. Agr. Exp. Sta. Mem. 129: 23 pgs.
4 - BEADLE. G. W. 1932 - A gene for sticky chromosomes in Zea Mays. Zeitsch. f. Induct. Vererb. 63: 195-217.
5 - BEADLE, G. W. AND B. MC CLINTOCK 1928 - A genie disturbance of meiosis in Zea Mays. Science 68: 433.
6 - BRIEGER, F. G. 1930 - Sebsterilitát und Kreuzungsterilität. Berlin. Springer. 395 pgs.
7 - BRIEGER, F. G. 1935 - The inheritance of self-sterility and the peloric flower shape in Antirrhinum. Genetic 10: 359-394.
8 - BRIEGER, F. G. 1936 - Self and cross polinization in Zea Mays and Nicotiana tabacum. 6th. Internat. Cong. Bot. 51-53.
9 - BRIEGER, F, G. 1937a - Genetic control of gametophyte development in maize. I. Gametophyte factors in chromosome five, Journal of Genetics. 34: 57-80.
10 - BRIEGER, F. G. 1937b. - Methoden der Erforschung der Verebungs vorgange bei Pflanzen. Handb. Biol. Methoden (Abderhalden) IX 3: 1183-1308.
11 - BRIEGER, F. G. 1944a - Considerações sobre o meca- nismo da evolução. Anais da Escola Agr. "Luiz de Queiroz". 1: 177-211.
12 - BRIEGER, F. G. 1944b - Estudos experimentais sobre a origem do milho. Anais da Escola Agr. "Luiz de Queiroz". 2: 225-278.
13 - BRIEGER, F. G. 1945a - A hereditariedade do milho tunicata da América do Sul. Anais da Escola Agr. "Luiz de Queiroz". 2:.
14 - BRIEGER, F. G. 1945b - Competição entre megaspó- rios em milho. Anais da Escola Agr. "Luiz de Queiroz". 2:.
15 - BRIEGER, F. G G. E. TIDBURY AND H. P. TSENG, 1938 - Genetic control of gametophyte development in maize. II. The quarter test. Journal of Genetics 36: 17-38.
16 - BRIEGER, F. G. AND A. J. MANGELSDORF 1926 - Lin- kage between a flower color factor and self sterility factors. Proc. Nat. Acad. Sc. (U.S.A.). 12: 248-255.
17 - BRINK, R. A. 1925 - Mendelian ratios and the gameto- phyte generation in Angiosperms. Genetics. 10: 359-394.
18 - BRINK, R. A. AND C. R. BURNHAM, 1927 - Differen- tial action of the sugary gene in maize on two alternative classes of male gametophytes. Gentics. 12: 348-378.
19 - CORRENS, C. 1912 - Selbsterilitát und Individuals toffe. Med. Nat. Ges. Munster. 84: 186-217. (Biol. Zentralblatt. 33: 389-423).
20 - CORRENS, C. 1928 - Neue Untersuchungen an selb- sterilen Pflanzen: Tolmiea Menziesii. Biol. Centralbl. 48: 759-768.
21 - DEMEREC, M. 1929 - Cross-sterility in maize. Zeitschr. f. Indukt. Vererbl. 50: 281-291.
22 - DREYFUS, A. E MARTA ERPS BREUER 1944 - O sexo nos Himenópteros Arrenótocos. Bol. Fac. Fil. XI- 5: 103 pgs.
23 - EAST, E. M. AND A. J. MANGELSDORF 1927 - Heredi- ty and selective pollen tube growth. Genetics. 11: 466-481.
24 - EAST, E. M. AND A. J. MANGELSDORF 1925 - A new interpretation of the hereditary behavior of self-sterile plants. Proc. Nat. Acad. (U.S.A.). 11: 166-171.
25 - EMERSON. R. A. 1934 - Relation of the differential fer- tilization genes, Ga ga, to certain other genes o the Su - Tu linkage group in maize. Gentics. 19: 137-156.
26 - FJLZER, P. 1926 - Die Selbst-sterilitât von Veronica syriaca. Zeitsch. Indukt. Vererb. 41 : 137-197.
27 - GOWEN, U. S. AND G. W. GOWEN 1922 - Complete lin- kage in Drosophila melanogaster. Am. Nat. 56: 92
28 - HARLAND, S. C. 1943 - Breeding of a cotton immune from natural crossing. Nature. 151: 307.
29 - JONES, D. F. 1922 - Selective fertilization and the rate of pollen tube growth. Biol, Bull. (Woods Hole). 43: 167-174.
30 - KEARNEY, T. H. 1923 - Self-fertilization and cross-fer- tilization in Pima cotton. U. S. Dept. Agr. Bull. Nr. 1134.
31 - KEARNEY, T. H. AND G. J. HARRISON 1924 - Selecti- ve fertilization in cotton. J. Agricult. Res. 27.
32 - KNIEP, H. 1920 - über morpholosgische und physiolo- gische Geschlechtsdifferenzierung. Verh. Phys. Med. Ges. Wurzbungg. 46: 18 pgs.
33 - MANGELSDORF, P. C. 1929 - The relaction between lenght of style and Mendelian segregation in a maize cross. Am. Nat. 63: 139-150.
34 - MANGELSDORF, P. C. 1931 - Modification of Mende- lian ratios in maize by mechanical separation of gametes. Proc. Nac. Acad. Sc. (U.S.A.). 17: 698-700.
35 - MANGELSDORF, P. C. AND D. F. JONES 1925 - The expression of Mendelian factors in the gametophyte of maize. Genetics. 11: 423-455.
36 - MANGELSDORF, P. C. AND REEVES 1939 - The origin of Indian Corn and its relatives. Texas Agr. Sta. Bull. 574: 1-315.
37 - RANDOLPH, L. F. 1936 - Developmental morphology of the caryopsis in maize. Jour. Agr. Res. 53: 881-916.
38 - RHOADES, M. M. 1938 - Effect of the Dt gene on the mutability of the al allele in maize. Genetics. 23: 377-388.
39 - ROSENBERG, O. 1927 - Die Semiheterotypische Teilung und ihre Bedeutung für die Entstehung vordoppelter Chromosomenzahlen. Hereditas. 8: 305-338.
40 - SINGLETON, W. R. AND P. C. MANGELSDORF, 1940 - Gametic lethals on the fourth chromosome of maize. Genetics. 25: 366-390.
41 - TACKOLM, G. 1922 - Zytolosgische Studie iiber die Gattung Rosa. Acta. Hort. Berg. 7: 97-381.
Recebido para publicação em 13-IX-1945.
- 1 - BALLS, w. L. 1911 - Cotton investigations in 1909 and 1910. Cairo Sci. J. 5.
- 2 - BEADLE, G. W. 1931 - A gene in maize for supernu- merary cell divisions following meiosis. Cornell Univ. Exp. Sta. Mem. 135: 12 pgs.
- 3 - BEADLE, G. W. 1930 - Genetical and cytological studies of Mendelian asynapsis in Zea Mays. Cornell Univ. Agr. Exp. Sta. Mem. 129: 23 pgs.
- 4 - BEADLE. G. W. 1932 - A gene for sticky chromosomes in Zea Mays. Zeitsch. f. Induct. Vererb. 63: 195-217.
- 5 - BEADLE, G. W. AND B. MC CLINTOCK 1928 - A genie disturbance of meiosis in Zea Mays. Science 68: 433.
- 6 - BRIEGER, F. G. 1930 - Sebsterilitát und Kreuzungsterilität. Berlin. Springer. 395 pgs.
- 7 - BRIEGER, F. G. 1935 - The inheritance of self-sterility and the peloric flower shape in Antirrhinum Genetic 10: 359-394.
- 8 - BRIEGER, F. G. 1936 - Self and cross polinization in Zea Mays and Nicotiana tabacum 6th. Internat. Cong. Bot. 51-53.
- 9 - BRIEGER, F, G. 1937a - Genetic control of gametophyte development in maize. I. Gametophyte factors in chromosome five, Journal of Genetics. 34: 57-80.
- 10 - BRIEGER, F. G. 1937b. - Methoden der Erforschung der Verebungs vorgange bei Pflanzen. Handb. Biol. Methoden (Abderhalden) IX 3: 1183-1308.
- 11 - BRIEGER, F. G. 1944a - Considerações sobre o meca- nismo da evolução. Anais da Escola Agr. "Luiz de Queiroz". 1: 177-211.
- 12 - BRIEGER, F. G. 1944b - Estudos experimentais sobre a origem do milho. Anais da Escola Agr. "Luiz de Queiroz". 2: 225-278.
- 13 - BRIEGER, F. G. 1945a - A hereditariedade do milho tunicata da América do Sul. Anais da Escola Agr. "Luiz de Queiroz". 2:.
- 14 - BRIEGER, F. G. 1945b - Competição entre megaspó- rios em milho. Anais da Escola Agr. "Luiz de Queiroz". 2:.
- 15 - BRIEGER, F. G G. E. TIDBURY AND H. P. TSENG, 1938 - Genetic control of gametophyte development in maize. II. The quarter test. Journal of Genetics 36: 17-38.
- 16 - BRIEGER, F. G. AND A. J. MANGELSDORF 1926 - Lin- kage between a flower color factor and self sterility factors. Proc. Nat. Acad. Sc. (U.S.A.). 12: 248-255.
- 17 - BRINK, R. A. 1925 - Mendelian ratios and the gameto- phyte generation in Angiosperms. Genetics. 10: 359-394.
- 18 - BRINK, R. A. AND C. R. BURNHAM, 1927 - Differen- tial action of the sugary gene in maize on two alternative classes of male gametophytes. Gentics. 12: 348-378.
- 19 - CORRENS, C. 1912 - Selbsterilitát und Individuals toffe. Med. Nat. Ges. Munster. 84: 186-217. (Biol. Zentralblatt. 33: 389-423).
- 20 - CORRENS, C. 1928 - Neue Untersuchungen an selb- sterilen Pflanzen: Tolmiea Menziesii. Biol. Centralbl. 48: 759-768.
- 21 - DEMEREC, M. 1929 - Cross-sterility in maize. Zeitschr. f. Indukt. Vererbl. 50: 281-291.
- 22 - DREYFUS, A. E MARTA ERPS BREUER 1944 - O sexo nos Himenópteros Arrenótocos. Bol. Fac. Fil. XI- 5: 103 pgs.
- 23 - EAST, E. M. AND A. J. MANGELSDORF 1927 - Heredi- ty and selective pollen tube growth. Genetics. 11: 466-481.
- 24 - EAST, E. M. AND A. J. MANGELSDORF 1925 - A new interpretation of the hereditary behavior of self-sterile plants. Proc. Nat. Acad. (U.S.A.). 11: 166-171.
- 25 - EMERSON. R. A. 1934 - Relation of the differential fer- tilization genes, Ga ga, to certain other genes o the Su - Tu linkage group in maize. Gentics. 19: 137-156.
- 26 - FJLZER, P. 1926 - Die Selbst-sterilitât von Veronica syriaca. Zeitsch. Indukt. Vererb. 41 : 137-197.
- 27 - GOWEN, U. S. AND G. W. GOWEN 1922 - Complete lin- kage in Drosophila melanogaster. Am. Nat. 56: 92
- 28 - HARLAND, S. C. 1943 - Breeding of a cotton immune from natural crossing. Nature. 151: 307.
- 29 - JONES, D. F. 1922 - Selective fertilization and the rate of pollen tube growth. Biol, Bull. (Woods Hole). 43: 167-174.
- 30 - KEARNEY, T. H. 1923 - Self-fertilization and cross-fer- tilization in Pima cotton. U. S. Dept. Agr. Bull. Nr. 1134.
- 31 - KEARNEY, T. H. AND G. J. HARRISON 1924 - Selecti- ve fertilization in cotton. J. Agricult. Res. 27.
- 32 - KNIEP, H. 1920 - über morpholosgische und physiolo- gische Geschlechtsdifferenzierung. Verh. Phys. Med. Ges. Wurzbungg. 46: 18 pgs.
- 33 - MANGELSDORF, P. C. 1929 - The relaction between lenght of style and Mendelian segregation in a maize cross. Am. Nat. 63: 139-150.
- 34 - MANGELSDORF, P. C. 1931 - Modification of Mende- lian ratios in maize by mechanical separation of gametes. Proc. Nac. Acad. Sc. (U.S.A.). 17: 698-700.
- 35 - MANGELSDORF, P. C. AND D. F. JONES 1925 - The expression of Mendelian factors in the gametophyte of maize. Genetics. 11: 423-455.
- 36 - MANGELSDORF, P. C. AND REEVES 1939 - The origin of Indian Corn and its relatives. Texas Agr. Sta. Bull. 574: 1-315.
- 37 - RANDOLPH, L. F. 1936 - Developmental morphology of the caryopsis in maize. Jour. Agr. Res. 53: 881-916.
- 38 - RHOADES, M. M. 1938 - Effect of the Dt gene on the mutability of the al allele in maize. Genetics. 23: 377-388.
- 39 - ROSENBERG, O. 1927 - Die Semiheterotypische Teilung und ihre Bedeutung für die Entstehung vordoppelter Chromosomenzahlen. Hereditas. 8: 305-338.
- 40 - SINGLETON, W. R. AND P. C. MANGELSDORF, 1940 - Gametic lethals on the fourth chromosome of maize. Genetics. 25: 366-390.
- 41 - TACKOLM, G. 1922 - Zytolosgische Studie iiber die Gattung Rosa. Acta. Hort. Berg. 7: 97-381.
Datas de Publicação
-
Publicação nesta coleção
25 Fev 2013 -
Data do Fascículo
1945
Histórico
-
Recebido
13 Set 1945
