Search Results

You are looking at 1 - 3 of 3 items for

  • Author or Editor: B. Apolinarska x
  • Refine by Access: All Content x
Clear All Modify Search

Chromosome pairing was studied at metaphase I in PMCs by C-banding in diploid rye plants with 1–3 monosomic-substitution wheat chromosomes and 1 monosomic-addition wheat chromosome. In plants with chromosome 5A, no univalents were found. In other plants with 1 monosomic-substitution wheat chromosome (7A, 2A, or 1A), only rye univalents occurred, on average 0.02–0.18 per PMC. Wheat chromosomes paired with homoeologous rye chromosomes in bivalents. The addition chromosome 6A occurred as a univalent with a frequency of 0.92 per PMC. In plants with 2–3 monosomic-substitution wheat chromosomes, no univalents were found. In 2 diploid rye plants with substitution chromosomes 2A, 5A and in 1 plant with 2A, 7A, wheat chromosomes paired mainly with rye homoeologues, but sometimes they paired with each other, forming heteromorphic wheat bivalent. In the other 3 plants with wheat chromosomes 2A, 5A, 2 plants with 2A, 7A, and 4 plants with 5A, 7A, a reverse situation was observed: nonhomoeologous wheat chromosomes paired with one another (forming a heteromorphic bivalent) more frequently than with rye homoeologues. In plants with 3 substitution wheat chromosomes (2A, 5A, 7A), 2 of them paired with each other, forming first of all a heteromorphic ring bivalent, while the third wheat chromosome paired with a rye chromosome in a ring bivalent or rarely in a rod bivalent. Wheat chromosomes sporadically occurred in multivalents. The presented data show that the rye genome promotes both homoeologous pairing of wheat and rye chromosomes and nonhomoeologous pairing of wheat chromosomes.

Restricted access

The objective of this study was to continue attempts to introduce wheat chromosomes, particularly those from the B genome, into diploid rye. An allohexaploid having 2 wheat mixogenomes (1B, 2A, 3B, 4B, 5B, 6A and 7B) and 4 rye genomes (RRRR) was crossed with substitution 2× rye containing the chromosomes of the wheat Agenome except 3A, and next backcrossed with substitution rye. Karyotypes were analysed by C-banding in the produced plants of the generations F 1 , BC 1 -F 1 , and BC 1 -F 2 . In nearly all plants of the F 1 generation (except one), 4–12 wheat chromosomes were found, mainly those of the B genome. A comparison of 2 successive generations indicates that both the mean and range of numbers of wheat chromosomes in the offspring of substitution plants and substitution-addition plants changed sometimes to the advantage of wheat chromosomes but sometimes to their disadvantage. A decline was observed in the contribution of B chromosomes and of chromosomes 2A and 6A, but pollen introduced some wheat chromosomes from the male parent: 1A, 4A, 5A and 7A. Wheat B chromosomes contributed to disturbances in plant development (lack of the spike emergence stage), but usually caused spike sterility, and even the single grains produced were usually unable to germinate. As a result, wheat chromosomes of the B genome were finally completely eliminated from the analysed material. The presence of wheat chromosomes of the A genome in fertile 2× rye plants, as well as their transfer to the next generations, indicate that the A genome is more closely related to the rye genome than the B genome. Positive introgression of wheat chromatin from the A genome into 2× rye depends to a large extent on chromosome engineering by means of appropriate crossing combinations, as A chromosomes from the male parent were much better tolerated than those from the female parent.

Restricted access

The D genome of wheat (Triticum aestivum cv. Panda) was used in this study to improve traits of hexaploid winter triticale (×Triticosecale Wittmack). Genome D expression was studied in hexaploid triticale lines with single substitutions (1D/1A, 3D/3A, 4D/4A, 5D/5A, 6D/6A, 7D/7A) and a line with 4 substitutions (1D/1A + 3D/3A + 4D/4A + 6D/6D). Chromosomes 1D and 3D have introduced to the analysed substitution lines resistance to wheat leaf rust (Puccinia triticina, synonym P. recondita f. sp. tritici) and resistance to preharvest sprouting (which is very important in hexaploid triticale), reflected in a high expression of seed dormancy, a high falling number, and low alpha-amylase activity in grain.

Restricted access