Sabharwal V, Negi M S, Banga S S, Lakshmikumaran M
TERI School of Advanced Studies (TERI SAS), Lodhi Road, Darbari Seth Block, Habitat Place, 110 003 New Delhi, India.
Theor Appl Genet. 2004 Jun;109(1):160-6. doi: 10.1007/s00122-004-1610-3. Epub 2004 Mar 16.
Association mapping of the seed-coat colour with amplified fragment length polymorphism (AFLP) markers was carried out in 39 Brassica juncea lines. The lines had genetically diverse parentages and varied for seed-coat colour and other morphological characters. Eleven AFLP primer combinations were used to screen the 39 B. juncea lines, and a total of 335 polymorphic bands were detected. The bands were analysed for association with seed-coat colour using multiple regression analysis. This analysis revealed 15 markers associated with seed-coat colour, obtained with eight AFLP primer combinations. The marker E-ACA/M-CTG(350 )explained 69% of the variation in seed-coat colour. This marker along with markers E-AAC/M-CTC(235 )and E-AAC/M-CTA(250) explained 89% of the total variation. The 15 associated markers were validated for linkage with the seed-coat colour loci using a recombinant inbred line (RIL) mapping population. Bands were amplified with the eight AFLP primer combinations in 54 RIL progenies. Of the 15 associated markers, 11 mapped on two linkage groups. Eight markers were placed on linkage group 1 at a marker density of 6.0 cM, while the remaining three were mapped on linkage group 2 at a marker density of 3.6 cM. Marker E-ACA/M-CTG(350 )co-segregated with Gene1 controlling seed-coat colour; it was specific for yellow seed-coat colour and mapped to linkage group 1. Marker E-AAC/M-CTC(235) (AFLP8), which had been studied previously, was present on linkage group 2; it was specific for brown seed-coat colour. Since AFLP markers are not adapted for large-scale applications in plant breeding, it is important to convert these to sequence-characterised amplified region (SCAR) markers. Marker E-AAC/M-CTC(235) (AFLP8) had been previously converted into a SCAR. Work is in progress to convert the second of the linked markers, E-ACA/M-CTG(350), to a SCAR. The two linked AFLP markers converted to SCARs will be useful for developing yellow-seeded B. juncea lines by means of marker-assisted selection.
在39个芥菜型油菜品系中开展了种皮颜色与扩增片段长度多态性（AFLP）标记的关联分析。这些品系具有遗传背景多样的亲本，种皮颜色和其他形态特征存在差异。使用11对AFLP引物组合对39个芥菜型油菜品系进行筛选，共检测到335条多态性条带。利用多元回归分析对这些条带与种皮颜色的关联性进行分析。该分析揭示了与种皮颜色相关的15个标记，由8对AFLP引物组合获得。标记E-ACA/M-CTG(350)解释了种皮颜色变异的69%。该标记与标记E-AAC/M-CTC(235)和E-AAC/M-CTA(250)共同解释了总变异的89%。利用重组自交系（RIL）作图群体对15个相关标记与种皮颜色基因座的连锁关系进行验证。用8对AFLP引物组合在54个RIL后代中扩增条带。在15个相关标记中，11个标记定位在两个连锁群上。8个标记位于连锁群1上，标记密度为6.0 cM，其余三个标记位于连锁群2上，标记密度为3.6 cM。标记E-ACA/M-CTG(350)与控制种皮颜色的基因1共分离；它对黄色种皮颜色具有特异性，定位在连锁群1上。之前研究过的标记E-AAC/M-CTC(235)（AFLP8）位于连锁群2上；它对褐色种皮颜色具有特异性。由于AFLP标记不适合在植物育种中大规模应用，因此将这些标记转化为序列特征化扩增区域（SCAR）标记很重要。标记E-AAC/M-CTC(235)（AFLP8）之前已被转化为SCAR。将第二个连锁标记E-ACA/M-CTG(350)转化为SCAR的工作正在进行中。这两个转化为SCAR的连锁AFLP标记将有助于通过标记辅助选择培育黄色种子的芥菜型油菜品系。
