Karyo-genetical studies on trigeneric triple hybrids in Triticinae
II. External characteristics, fertility and the number of somatic chromosomes of TperHRF1 and TdurHRF1 pants
1959 Volume 34 Issue 2 Pages 61-69
Details
1959 Volume 34 Issue 2 Pages 61-69
1. In the present reports, the external characteristics, fertility and the number of somatic chromosomes of trigeneric triple F1 hybrids raised from Triticum persicum×Haynaldia villosa F1×Secale cereale (Tper HRF1) and T. durum×H. villosa F1×S. cereale (Tdur HRF1) are treated respectively.
2. The percentage of the triple F1 plants againts the number for the pollinated florets in the hybrid Tper HRF1 was higher than that of the hybrid TdurHRF1 (Table 1).
3. The number of somatic chromosomes of Triticum-Haynaldia-Secale trigeneric triple F1 hybrids was found to vary from 25 to 32 in TperHRF1 and from 24 to 32 in Tdur HRF1 (Table 2 and 3). And the somatic number of chromosomes of eu-trigeneric triple F1 hybrids in these two combinations is 28. This number corresponds exactly to the sum of the gametic numbers of the three parental plants (Triticum persicum or durum 28+Haynaldia villosa 7+Secale cereale 7=28). 7 chromosomes out of the 25-32 or 24-32 chromosomes as the somatic number of these two trigeneric triple F1 hybrids are from S. cereale as the pollen plant, and the remaining 18-25 or 17-25 chromosomes must have been from TperHF1 or TdurHF1 as the mother plants. The number of somatic chromosomes of TperHF1 and TdurHF1 in these two combinations was found to be 21 respectively, therefore, up to 21 of the 17-25 chromosomes derived from mother plants are due to the irregular distribution of the chromosomes or to the formation of the equatorial plate, but the 1-4, which is in excess of 21, may be due to the non-disjunction of the chromosomes in the meiosis of the mother plants. And it is difficult to as-certain whether those surplus chromosomes came from the Triticum or the Haynaldia.
4. The variation was observed among these groups and among the individuals of each group, in the external characteristics of these two trigeneric triple F1 plants. The remarkable differences were observed among the individuals in each group, due perhaps to the different constitution of chromosomes in the individuals of each group, though they have the same number of chromosomes. The external characteristics of these F1 plants and their parental plants are shown in Table 4 and Photo. 1. Generally speaking, although these F1 plants possess the external characteristics of the three parents, they resemble somewhat more closely to the original mother plant Triticum (Photo. 1).
5. Most of the individuals of TperHRF1 and TdurHRF1 were almost sterile, but in extremely rare cases, some anthers opened and some grains were obtained in natural selfing (Table 5) and by sowing them in October 1958, many F2 plants were raised.
