BGN 13: Additional information of genetic analysis with acrotrisomic lLlS and triple marker stock f8 lk2 n BARLEY GENETICS NEWSLETTER, VOL. 13, II. RESEARCH NOTES
Shahla  and Tsuchiya, pp. 28-29

II. 14. Additional information of genetic analysis with acrotrisomic lLlS and triple marker stock f8 lk2 n. (1)

Azizeh Shahla and T. Tsuchiya, Department of Agronomy, Colorado State University, Fort Collins, C0 80523 U.S.A.

(1) Supported in part by USDA/SEA Competitive Research Grant 5901-0410-90334-0 and 82-CRCR-1-1020 and USDA/SEA CSU Cooperative Research Grant 58-9AHZ-2-265 to T. Tsuchiya.

Additional information was obtained for physical localization of three genetic marker genes, f8, lk2, and n, in the long arm of chromosomes 1 (1L). The previous results from the genetic analysis of acrotrisomic lLlS and the triple marker stock did not show clearly the nature of the deficiency in the long arm of acrocentric chromosome lLlS (Tsuchiya and Fujigaki, 1981; Tsuchiya, et al. 1983). In the present study more F2 plants were grown and the segregation ratios were observed (Table 1).

Table 1. Segregation ratios in F2 generations in crosses of acrotrisomic lLlS with a triple marker stock f8 lk2 n.

Segregation ratios for lk2 and n did not fit to disomic (3:1) ratio, but many homozygous trisomics were recovered for each mutant gene.  These results indicate that all three genes are located on the missing segment of the long arm of acrocentric chromosome lLlS. The number of trisomic plants which showed the n character is less than the corresponding numbers for f8 and lk2, because several trisomic plants did not set any seeds. The presence of 5 recessive homozygotes for naked karyopsis (n) in the trisomic position indicates that the acrocentric chromosome lLlS does not carry the n mutant.

References:
Tsuchiya, T. and J. Fujigaki. 1981. Genetic analysis with acrotrisomic lLlS . BGN 11:59-60.

Tsuchiya, T., R. J. Singh, Azizeh Shahla and A. Hang. 1983) Acrotrisomic analysis in linkage mapping in barley. Can. J. Genet. Cytol. (Submitted).

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