BGN 19: Effect of Ant genes on aleurone color

Effect of Ant genes on aleurone color

F. Gonzalez Ceniceros and J.D. Franckowiak
Department of Crop and Weed Sciences
North Dakota State University
Fargo, North Dakota 58105, U.S.A.


Ant mutants of barley which suppress expression of some or all the colored pigments in the plant may also affect grain pigments. To confirm the effect of ant genes on aleurone color, twelve Ant mutants were crossed to the blue-aleurone experimental line ND6976 (B1B1 B12B12 AntAnt).

F2 seeds and F3 progenies were utilized for this study. F2 seeds of crosses were soaked for 24 hours in a petri plate before scoring for blue aleurone; seeds of F3 progenies were pearled for ten seconds so partial removal of hulls occurred. All parents from which ant mutants were induced had a white aleurone layer and were assumed to be homozygous for the b1 or b12 allele for aleurone color, because white aleuroned cultivars usually contain only one gene for white aleurone (Meyer and Stanford, 1942).

F2 seeds of nine of the crosses showed a fit to a 9:7 ratio for blue and white aleurone, respectively (Table 1). This segregation is expected if the mutants are recessive at one locus for white aleurone (b1 or b12) and are homozygous for an ant allele which prevents the formation of blue color. Five F3 progenies were analyzed to confirm F2 segregation data (Table 1). F3 results agreed with F2 data and often showed a better fit to the expected ratio as it was easier to score F2 progenies than F2 seeds for aleurone color.

Table 1. F2 and F3 segregation ratios for blue (B) and white (W) aleurone of nine Ant mutants crossed to ND6976.

Three crosses segregated in a different manner (Table 2). Chi- square values indicated a good fit to a 27:37 blue to white ratio, which is expected if three genes were segregating for aleurone color. The F3 generation of one cross was planted to confirm F2 data and the results showed a better fit to the expected ratio than the F2 data. It is assumed that the parental lines of Ant 548 (Cree), Ant 581 (Dickson) and Ant 582 (Dickson) have both the b1 and b12 genes for white aleurone.

Table 2. F2 and F3 segregation ratios for blue (B) and white (W) aleurone of three Ant mutants crossed to ND6976.

The mutants utilized in this study were allelic at the ant13, ant17, or ant18 loci (Jende-Strid, 1988), which produce a lack of pigments in all plant parts and are deficient in anthocyanidins, proanthocyanidins and catechins (Jende-Strid, 1984). Thus, the recessive alleles at these loci also prevent the formation of blue aleurone color, adding several recessive factors to the list of genes that affect expression of blue aleurone in barley. Similar affects of the ant genes on blue aleurone pigment were reported by Boyd and Falk (1988).

References:

Boyd, P.W., and D.E. Falk. 1988. The interaction of blue aleurone and proanthocyanidin in barley seeds. Barley Newsl. 31:110.

Jende-Strid, B. 1984. Coordinator's report: Anthocyanin genes. BGN 14:76-79.

Jende-Strid, B. 1988. Coordinator's report: Anthocyanin genes. Stock list of ant mutants kept at the Carlsberg Laboratory. BGN 18:74-79.

Myler, J.L., and E.H. Stanford. 1942. Color inheritance in barley. Agron. J. 34:427-436.


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