Summary
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1.
The types of chromosome associations found during diakinesis and metaphase I of meiosis in microsporocytes was studied in plants belonging to the C1, C2, C17, C18 and C19 generations of induced tetraploids of strain 22 ofBrassica campestris var.toria. It was found that there was a considerable decrease in the frequency of multivalents and increase in the frequency of bivalents in tetraploid plants belonging to the later generations in comparison with those belonging to the earlier generations.
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2.
The mean number of seeds per siliqua in the C1 and C2 tetraploids was 1.5 and 3.0 respectively, while this number increased to 14.5, 14.9 and 16.8 in C17, C18 and C19 generations respectively. The increase in seed fertility had been brought about by adopting the mass pedigree system of selection.
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3.
From the observation that coincident with an increase in seed fertility there is a tendency towards a decrease in multivalent frequency in autotetraploidToria, it is suggested that the relationship between these two processes may not be wholly casual.
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Literature
Armstrong, J. M., andR. W. Robertson: Studies of colchicine induced tetraploids ofTrifolium hybridum L. I. Cross and self fertility and cytological observations. Canad. J. agric. Sci.36, 255–266 (1956).
Bremer, G., andD. E. Bremer-Reinders: Breeding of tetraploid rye in the Netherlands. I. Methods and cytological investigations. Euphytica3, 49–63 (1954).
Darlington, C. D.: Recent advances in cytology, 2. edit Philadelphia: Blakiston 671 pp. 1937.
Gilles, A., andL. F. Randolph: Reduction of quadrivalent frequency in autotetraploid maize during a period of 10 years. Amer. J. Bot.38, 12–17 (1951).
Hagberg, A.: Frekvensen av plantor med avvikande kromosomtal i marknadspartior av tetraploid råg (Dubbelstålråg). Kungl. Lantbruksakad. Tidskr.92, 417–427 (1953).
Harland, S. C.: Methods and results of selection experiments with Peruvian Tanguis cotton. Part I. A survey of present methods of cotton breeding and a description of the “Mass Pedigree System”. Part II. The “Mass Pedigree System” in practice. Emp. Cotton Gr. Rev.26, 163–174, 247–255 (1949).
Hilpert, G.: Effect of selection for meiotic behaviour in auto-tetraploid rye. Hereditas (Lund)43, 318–322 (1957).
Howard, H. W.: The cytology of autotetraploid Kale,Brassica oleracea. Cytologia (Tokyo)10, 77 bis 87 (1939).
Müntzing, A.: Cytogenetic properties and practical value of tetraploid rye. Hereditas (Lund)37, 18–84 (1951).
—: Chromosomes in relation to species differentiation and plant breeding. Conference on chromosomes, W. E. J. Tjeenk Willink, Zwelle the Netherlands. Lecture6, 1–37 (1956).
Müntzing, A., andR. Prakken: The mode of chromosome pairing inPhleum twins with 63 chromosomes and its cytogenetic consequences. Hereditas (Lund)26, 463–501 (1940).
Parthasarathy, N., andS. S. Rajan: Studies in the fertility of autotetraploids ofBrassica campestris var.toria. Euphytica2, 25–37 (1953).
Rajan, S. S.: The effectiveness of the mass pedigree system of selection in the improvement of seed setting in autotetraploids ofToria. Indian J. Genet.15, 47–49 (1955).
Ramanujam, S., andM. J. Deshmukh: Colchicine induced polyploidy in crop plants. III. Oleiferous Brassicae. Indian J. Genet.5, 63–81 (1945).
Riley, R., andV. Chapman: Genetic control of the cytologically diploid behaviour of hexaploid wheat. Nature (Lond.)182, 713–715 (1958).
Sears, E. R., andM. Okomoto: Proc. 10. Int. Congr. Genet.2, 258–259 (1958).
Stebbins, G. L.: Artificial polyploidy as a tool in plant breeding. Brookhaven, Symp. Biol.9, 37–52 (1956).
Swaminathan, M. S., M. L. Magoon andK. L. Mehra: A simple propionocarmine PMC smear method for plants with small chromosomes. Indian J. Genet.14, 87–88 (1954).
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Swaminathan, M.S., Sulbha, K. Multivalent frequency and seed fertility in raw and evolved tetraploids of Brassica campestris var. toria. Zeitschrift für Vererbungslehre 90, 385–392 (1959). https://doi.org/10.1007/BF00888813
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DOI: https://doi.org/10.1007/BF00888813