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771.
Doubled haploid plant production from unpollinated ovules of sugar beet (Beta vulgaris L.) 总被引:2,自引:0,他引:2
The effects of cold pretreatment, AgNO3 and activated charcoal on haploid plant production from unpollinated sugar beet ovules were investigated. Both cold pretreatment
and the addition of charcoal increased the frequency of embryo formation, whereas AgNO3 decreased or completely inhibited it. Colchicine (50, 100, 150 or 500 mg l–1) and trifluralin (1.7, 3.4 or 5.0 mg l–1) for 12, 24, 36 or 48 h were compared in agar-solidified, agarose-solidified or liquid media. Although colchicine gave a
higher doubling rate (25.3%) than trifluralin (18.2%), the difference was not significant. Both agents were more effective
when used in liquid (29.1%) than agarose-solidified medium (20.7%) and agar-solidified medium (15.4%). A treatment duration
of 48 h was significantly more effective (27.5%) than 12 h (13.6%) but it was not different from 24 h (16.3%) or 36 h (18.6%).
Received: 25 October 1999 / Revision received: 18 May 2000 / Accepted: 29 May 2000 相似文献
772.
Z. Kaya M. M. Sewell D. B. Neale 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1999,98(3-4):586-592
Quantitative trait loci (QTLs) for annual height- and diameter-increment growth were estimated in each of two three-generation
loblolly pine pedigrees. Annual height-increment was measured in three consecutive years in the BASE pedigree and in four consecutive years in the QTL pedigree. Annual diameter-increment was measured only in the QTL pedigree for two consecutive years. An interval mapping-approach was used to estimate the number of QTLs, the magnitude of
QTL effects, and their position on genetic linkage maps. Thirteen different height-increment and eight different diameter-increment
QTLs were detected, suggesting that the these traits are, at least in part, controlled by a few genes of large effect. Little
evidence was found for the expression of individual QTLs in multiple years or in multiple genetic backgrounds. These results
were discussed in terms of the power of the experiment and their consequences for marker-assisted breeding.
Received: 12 July 1998/Accepted: 5 August 1998 相似文献
773.
A hydroxy fatty-acid-combined taurine (lipotaurine) was found in the taurolipids fraction of Tetrahymena thermophila. Lipotaurine accounted for about 1.4% of the total taurolipids of the cells, and was composed of taurine and 7,13-dihydroxy-2-trans-octadecenoic acid. By nuclear magnetic resonance, mass and infrared spectrometries, the chemical structure of lipotaurine was identified as 2-(7,13-dihydroxy-2-trans-octadecenoylamino)ethanesulfonic acid. When cells of T. thermophila were incubated with the double-labeled lipotaurine which was biosynthesized from [2(n)-3H]taurine and [1-14C]stearic acid, both the radioactivities were detected in taurolipid A, B and C. Furthermore, the ratio of the radioactivities of 3H and 14C in the lysotaurolipids were the same as that of the lipotaurine. From these results, it is suggested that lipotaurine is an intermediate of taurolipid biosynthesis. 相似文献