Chromosome mapping in barley by means of telotrisomic analysis

Summary

A total of 37 genetic markers located in chromosomes 2, 3, 4 and 5 were associated with specific arms by means of telotrisomic analysis in five telotrisomics (Triplo 2 L, 2 S, 3 S, 4 S, 5 L) of barley (Hordeum vulgare L.). The genes v, gp (= gp 2), li, gs 5, tr and msg2 showed a trisomic ratio with Triplo 2 L indicating that these genes were on the long arm of chromosome 2. A disomic ratio was obtained for genes wst 4, gs 5, and v with Triplo 2 S, confirming that these genes were on the long arm of chromosome 2(2 L). A disomic ratio was observed for genes e, f(= lg), sk, and gs6 with Triplo 2 L. Two genes, f(= lg) and gs6 showed a trisomic ratio with Triplo 2S. These results indicated that genes e, f(= lg), sk, and gs 6 are on the short arm of chromosome 2 (2S). Since only one telocentric chromosome was available for chromosome 3, 4 and 5, most of the well-mapped marker genes were tested with those telocentric chromosomes. The genes cu 2, uz, wst, als, gs 2, zb,f2, and cer-zn ³⁴⁸ showed trisomic ratio with the telocentric for chromosome 3. These genes were located on the short arm of chromosome 3 (Robertson 1971). This indicated that the telocentric chromosome is for the short arm of chromosome 3(3 S). A disomic ratio was obtained for genes yst, x _c, al, yst2, a _n, ari-a ⁶ and x _s, indicating that these genes are on the long arm of chromosome 3. Two genes, f9 and K, showed trisomic ratio with the telocentric chromosome for 4, while genes gl(= gl2), br2, yh, lg 3, lg 4 and lk 5 showed disomic ratios. This indicated that the telocentric chromosome is for the short arm of chromosome 4. Two genes, fs 2 and g, were studied with Triplo 5 L. Both showed trisomic ratio, indicating that fs 2 and g are located on Triplo 5 L. The centromere position (C) on chromosome 2, 3 and 4 was thus located as (the left side of C is the short arm and the right is the long arm): chromosome 2: f — sk — gs6 — e — C — gs5 — msg2 — wst4 — v — gp — li — tr; chromosome 3: f2 — cer-zn ³⁴⁸ — uz — gs2 — als — cu2 — wst — zb — C — yst — x _c — al — yst2 — a _n — ari-a ⁶ — x _s; chromosome 4: f9 — K — C — lg4 — lg ³ — gl2 — br2 — lk5 — yh. The centromere position on chromosome 5 was not precisely located.