| Irradiation of rye pollen When gamma-irradiated pollen of two rye cultivars was used in crosses with two common-wheat cultivars, a substantial increase of viable F1 kernels was obtained over the control crosses (Table 3). The best set of viable F1 kernels was obtained at gammaray doses of 0.05 kR-0.4 kR (15 kR/hr). In contrast to the irradiated Triticale pollen, irradiated rye pollen resulted in an increased kernel set; the germination capacity of these kernels remained constant up to a dose of 0.8 kR. Conclusion Irradiation of rye and 6x Triticale pollen effectively facilitates the production of primary octaploid and secondary hexaploid Triticales, respectively. Acknowledgements The use of facilities of the Department of Agricultural Technical Services is gratefully acknowledged. My sincere thanks are also due to Drs. F. J. HAASBROEK and C. J. VISSER of the Fruit and Food Technology Research Institute for irradiating the Triticale and rye spikes, and to Messrs. H. A. van Niekerk, K. W. Pakendorf, G. F. Marais, T. Paxton and L. Ehlers for some assistance in making the crosses and the germination tests, to various institutes for seed samples, and to Dr. E. R. SEARS for editing this paper. Literature cited BREWBAKER, J. L. and G. C. EMERY 1962. Pollen radiobotany. Rad. Bot. 1: 101-154. JENKINS, B. C. 1969. History of the development of some presently promising hexaploid Triticales. Wheat Inf. Serv. 28: 18-20. JORDAAN, J. P., F. X. LAUBSCHER and F. P. CILLIE 1970. The potential of Triticales. Proc. 4th Congr. S. Afr. Genet. Soc., Pretoria: 70-76. KNOBLOCH, I. W. 1968. A checklist of crosses in the Gramineae. Mich. State Univ., East Lansing: pp. 170. KROWLOW, K. D. 1970. Untersuchungen uber die Kreuzbarkeit zwischen Weizen und Roggen. Z. P-flan (enzuchtg. 64: 44-72. KRUSE, A. 1967. Intergeneric hybrids between Hordeum vulgare L. ssp. distichum (v. Pallas, 2n=14) and Secale cereale L. (v. Petkus, 2n=14). Kgl. Vet. og. Landbohojsk. Arsskr.: 82-92. KRUSE, A. 1969. Intergeneric hybrids between Triticum aestivum L. (v. Koga II, 2n = 42) and Avena sativa L. (v. Stal, 2n=42) with pseudogamous seed formation. Kgl. Vet. og Landbohojsk. Arsskr.: 188-200. RILEY, R., and V. CHAPMAN 1967. The inheritance in wheat of crossability with rye. Genet. Res. 9: 259-267. ROMMEL, M. 1958. Eine vereinfachte Methode der Embryokultur bei Getreide. Zuchter 28: 149-151. SISODIA, N. S. and R. C. MCGINNIS 1970a. Importance of hexaploid wheat germ plasm in hexaploid Triticale breeding. Crop Sci. 10: 161-162. SISODIA, N. S and R. C. MCGINNIS 1970b. New methods of utilizing wheat and rye germ plasm in Triticale breeding. Crop Sci. 10: 163-164. (Received August 20, 1973) |
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