BGN 2: An incomplete dominant chlorophyll mutation on chromosome 1 BARLEY GENETICS NEWSLETTER, VOL. 2, II. RESEARCH NOTES
Konishi, pp. 43-45

II.12. An incomplete dominant chlorophyll mutation on chromosome 1.

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

A strain segregating xantha, chlorina and green seedlings was found among the M2 strains of EMS treated population of the hybrid between Akashinriki and a linkage tester 191. The xantha plants died and the latter two survived. When grown in the greenhouse and in the field, the chlorina plants could be clearly distinguished from the green ones at any stage from seedling to near maturity.

In F1 of the cross between the chlorina plant and several green plants, chlorina and green ones appeared in a 1:1 ratio. In the progenies of the chlorina F1 plants, xantha, chlorina and green plants appeared in a ratio of 1:2:1. The result can be explained on the assumption that the xantha is homozygous for Xa and the chlorina heterozygous for Xa.

Table 1 shows segregation of several gene pairs on the respective chromosomes in the F2 generation of the four crosses. The results indicate that the chlorophyll deficiency is inherited independently of l (chromosome 1), v (2), uz (3), K (4), trd (5), o (6), and s (7), but is in linkage with lk for short awn and n for naked kernel, both on chromosome 1. The interrelationships between Xa and three genes, lk, n and l, on chromosome 1 were studied by growing F3 progenies from a cross between the chlorina plant and Shin Omugi. The results given in Table 2 and Fig. 1 have indicated that the four genes, Xa, lk, n and l, are in linkage and arranged in this order.

The chlorophyll mutant gene, Xa, may be useful for linkage studies, because it is located on the long arm of chromosome 1 more distal than lk for short awn that has hitherto been regarded to occupy its distal end.

Table 1. F2 segregation of several character pairs in the four crosses with the chlorina mutant (E3 811).

Table 2. Linkage data for Xa, lk, n and l.

Figure 1. Proposed arrangement of genes on chromosome l.

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