Colchicine処理によって得たAutotetraploid rye

Abstract

1. In this investigation external characters and maturation division in PMC's of autotetraploid rye produced by means of colchicine method were studied. 2. Autotetraploid rye was produced by means of injection method employing 0.1 and 0.05 % aqueous solution of colchicine, and the latter case was proved to be more available. 3. The tetraploids were inferior in length of stem and percentage of seed fertility to the diploid (Table 1). 4. The kernels of autotetraploids were much larger than those of diploids. 1000 kennels of tetraploids and those of diploidsw eight 49. 6 gr. and 34. 5 gr. respectively, in other words, the kernel weight of tetraploids is 43.77 % larger than that of diploids. 5. In most cases, the number of somatic chromosomes of autotetraploids was 28, while in very rare cases 27 was observed. 4 members (two pairs) of those 28 chromosomes have each a satellite at one end. 6. The 28 chromosomes correspond to twice the somatic chromosome number of original diploid rye. Further, in meiosis of PMC's of tetraploids 14II were observed. 7. At metaphase in heterotypic division of PMC's of tetraploids, 0 - 8 univalents and consequently 10-14 brvalents were sometlmes observed (Table 2). These univalents may have been produced from some bivalents dividing earlier than the others. 8. Tetravalent chromosomes which is characteristic of tetraploid plants were observed in rarecases, but no trivalent was observed. 9. There is a marked incompatibility between autotetraploid rye and original diploid of it.