BGN 10: Interallelic recombination at the ligule-less (li) locus in barley BARLEY GENETICS NEWSLETTER, VOL. 10, II. RESEARCH NOTES
Konishi, pp. 39-40

II. 17. Interallelic recombination at the ligule-less (li) locus in barley.

T. Konishi. The Ohara Institute for Agricultural Biology, Okayama University, Kurashiki, 710 Japan.

In my previous experiments (Konishi 1974, 1979), it was confirmed that both Akashin li-l and Chikurin li-l were markedly different from 15 other li strains in spontaneous reversibility to normal Li (Table 1), suggesting difference in the fine structure of li locus.

Table 1. Spontaneous reversion frequency in 4 ligule-less strains used as parents.

The present investigation aimed to know whether normal plants with well-developed ligules and auricles would be found as the result of interallelic recombination in the F2 generation of the crosses between nonrevertible li strains. As the materials, four out of the 15 non-revertible li strains shown in Table 1, were selected and mutually crossed in all combinations. To avoid contamination, special care was taken in raising the resulting F1 plants by surrounding the field with wheat plants. F2 plants were grown in a greenhouse, and the presence and absence of ligules was examined at the seedling stage.

According to Table 2, normal-appearing seedlings among these F2 hybrid populations were observed in five out of the six crosses. The frequencies ranged from 0 to 4.2 x 10-4. No recombinant was observed in F2 hybrid population of Akashin li-2 and Muyoji, while the maximum frequency was observed in the cross of Bonus li-1 to Koyo li.

Table 2. Frequency of normal appearing seedlings in F2 hybrid populations in all combinations of 4 ligule-less strains.

It is noted that the maximum value obtained approximates the maximum frequency (4.4 x 10-4) at the locus of ml-o for mildew resistance in barley found by Jørgensen and Jensen (1979).

These results suggested to us that four li mutants employed in this experiment resulted from a change in different sites at the li locus, which is as shown in Fig. 1. The li locus could be divided into a minimum of three different sites.

Figure 1. Preliminary map of the fine structure at li locus (x 10-4).

References:

Jørgensen, J. Helms and H. P. Jensen. 1979. Inter-allelic recombination in the ml-o locus in barley. Barley Genetics Newsletter 9:37-39.

Konishi, T. 1979. Reverse mutation at the ligule-less (li) locus in barley. Barley Genetics Newsletter 5:21-23.

Konishi, T. 1979. Studies on reverse mutation at the ligule-less (li) locus in barley. Nogaku Kenkyu 58:1-11.

BGN 10 toc
BGN Main Index