Chromosome 1 -- R. K. Soost. ms\6 is 30 units from y, gs is 45 units from y and 37 from br. au is close to y and 32 from br.
Chromosome 2 -- L. Butler. This group has been completely remapped as in the diagram, and the results have been submitted for publication. The aw Cu Me Wo region appears to be duplicated in certain stocks.
Chromosome 3 -- G. W. Bohn. No ms\9 r crossovers were observed in a small F2 population of 82 plants of Rick's 48-110 cross. Some of the progenies resulting from sib crossing may yield the ms\9 r plants. Some F2 ms\9 plants were pollinated with wf r pollen. Some of these progenies may contain ms\9 r plants that are heterozygous for wf. Seeds will be sent to anyone wishing to help locate such plants. We hope to establish, eventually, a stock homozygous for the three markers.
Chromosome 4 -- N. K. Notani. No report, but not sufficient time to accumulate stocks.
Chromosome 5 -- not assigned.
Chromosome 6 -- J. C. Gilbert. See research note in this report. The relative positions of c to sp and yv, Cf2 and Mi are still uncertain but md is known to lie between c and Mi. B and ri were not mapped.
Chromosome 7 -- H. W. Young. Crosses have been made to extract the following triple recessives tf wt Fw, tf wt n, tf wt go, tf mc gq, tf Fw n, tf Fw gq. I am still in doubt about the Fw genotype. Crosses have been made of tf wt mc to Bp (broad petiole).
Chromosome 8 -- C. M. Rick. As detailed in a research note, the new gene ch has been positioned between bu and l\1. va^virg lies close to dl.
Chromosome 9 -- C. M. Rick. A large F2 for wd x ah was rogued to ah and planted in the field. Only 2 of the 281 total ah were also wd. The ah/ah condition of these 2 plants was verified by progeny test. These data, which disagree with previous figures ++ (TGC 8:33), are considered more trustworthy, and provide an estimate of 1.4% crossingover.
Chromosome 10 -- E. A. Kerr. I am suggesting pe 8 lg 35 u 24 h 18 l\2 13 t 32 Xa 15 ag. Segregating populations now being grown should give h nd t^v ag and u h nd l\2 which will be used for crossing this spring.
Chromosome 11 -- not assigned.
Chromosome 12 -- not assigned.
Group V - T. R. Martens, and A. B. Burdick. No report.
Group rv sf -- Watkin Williams. None of the stocks sent gave rv sf, and I am selling F2 plants to get the double recessive. I have no idea how fertile the double recessive will be but judging by the difficulty in setting rv/rv, the double recessive is likely to prove quite difficult. I should appreciate seed of rv sf.
L. Butler
Chairman, Linkage Committee