Abstract
1. In the present paper cytogenetical researches on the F1 plants raised from Triticum sphaerococcum crossed with 3 species of Secale (Vavilovii, africanum and montanum) are dealt with.
2. Among the 3 combinations, the percentage of the F1 obtained to the number of the pollinated flowers was highest in the hybridization between T. sphaerococcum and S. montanum, and lowest with S. Vavilovii (Table. 1)
3. The external characters of F1 plants raised from the 3 combination resembled to the parents, although much more closely to mother plant than being the intermediate of the parents.
4. The 3 F1 hybrids showed fertility in natural selfing though lower in percentage.
5. The number of somatic chromosomes in root tip cells of the 3 F1 hybrids was 28 which corresponds exactly to the sum of the gametic number of chromosomes of the parents.
6. The F1 hybrids of the 3 combinations showed differences in the number of bivalents according as the pollen parents are different though the mother plant was common.
7. In the 3 F1 hybrids, the number of bivalents at heterotypic metaphase of PMC's was given in Tables 4, 5 and 6.
