| Crossing Secale cereale with Triticale has been unsuccessful
in all three years. However, it is almost certain, if crosses were made
with more rye varieties and in larger numbers in this direction seed set
would occur. In 1967, 218 plants were cultivated in the first generation of a hexaploid Triticale x Secale cereale cross. Out of them 104 plants were entirely sterile; 114 plants were slightly fertile. In case of a segregation of 1:1 the chi2 value is 0.458 P% = 50-30. In 1968, we only got 8 F1 plants; 5 sterile and 3 slightly fertile ones. F1 hybrids were 2.9-25.0 cm taller than the taller parent. In maturity they stood between Triticale and rye. Ears were stirikingly similar to sterile ears of Triticale. The rye character asserted itself in the size of the auricle, while that of Triticale in its red color. The meiosis of only 4 F1 plants with 28 chromosomes was examined (1315 pollen mother cells). It appeared that univalent chromosomes varied between 6-18. The number of cells containing 7 bivalents varied individually, the smallest value being 30.6, the highest 37.5%. In two cases cells with 6 bivalents were present in the largest numbers (34.7-48.7%). Examination showed that there are much more bivalents in hybrids from hexaploid Triticale x Secale cereale crosses than in hybrids of hexaploid wheat x Secale cereale. In 1968, 333 BCF1 plants were grown; 38 plants were completely sterile, 168 plants yielded about 50 seeds, 110 plants had a grain yield between 100-500, 14 plants between 550-1000, and only 3 plants yielded more than 1,000 seeds. Seed set on the principal ear of the 333 plants was examined separately (Table 2). Data are not identical with the values obtained per plant, all the more as there are more sterile and at the same time more fertile ears among the chief ones. Grain yeild is surprisingly good; in earlier years we have never succeeded in propagating Triticale x rye hybrids beyond their second generation. In 1969 BCF2 generations of hexaploid Triticale2 x Secale cereale were divided into 3 groups: 1. Triticale-like individuals with moderate fertility, 2. rye-like plants with poor fertility and 3. F1-like, very sterile plants with intermediate type. Fertility per chief ear for each group is shown on Table 3. Cytological studies are in progress. We hope selection will succeed in both directions (rye and Triticale). For the first time in our trials we could thus develop hexaploid. Triticale and Secale cereale respectively from Triticale2 x rye cross. Literature cited SMUTKUPT, S. 1968. Herstellung und Eigenschaften von Secalotricum im Vergleich mit Triticale. Angewandte Botanik 42(3/4): 95-118. SULUNDIN, A. F. and L. M. NAUMOVA 1965. Amfidiploidi polucsennie ot Szkrescsivanyija ozimoj tverdoj psenyici sz rozsju. Szelekcija iszemenovodsztvo 1: 52-55. TARKOWSKI, C. 1966. Cytogenetica, hodowla i wartosc rolnicza prszenzyta (Triticale). Postepy Nauk Rolnych, Warszawa. 4: 35-54. TARKOWSKI, C. and D. OTLOWSKA 1968. Preliminary research on hexaploid Triticale x tetraploid and diploid rye hybrids. Genetica Polonica 9(1-2): 49-58. N. N. 1968-69. Cross-compatibilities among wheats, Triticales and rye CIMMYT. Mexico. 82-97. (Received July 4, 1970) |
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