Kiss G B, Csanádi G, Kálmán K, Kaló P, Okrész L
Institute of Genetics, Biological Research Center, Hungarian Academy of Sciences, Szeged.
Mol Gen Genet. 1993 Apr;238(1-2):129-37. doi: 10.1007/BF00279539.
The genetic map for alfalfa presented here has eight linkage groups representing the haploid chromosome set of the Medicago species. The genetic map was constructed by ordering the linkage values of 89 RFLP, RAPD, isozyme and morphological markers collected from a segregating population of 138 individuals. The segregating population is self-mated progeny of an F1 hybrid plant deriving from a cross between the diploid (2n = 2x = 16) yellow-flowered. Medicago sativa ssp. quasifalcata and the diploid (2n = 2x = 16) blue-flowered M. sativa ssp. coerulea. The inheritance of many traits displayed distorted segregation, indicating the presence of lethal loci in the heterozygotic parent plants. In spite of the lack of uniform segregation, linkage groups could be assigned and the order of the markers spanning > 659 centimorgans could be unambiguously determined. This value and the calculated haploid genome size for Medicago (1n = 1x = 1.0 x 10(9) bp) gives a ratio of < 1500 kb per centimorgan.
本文展示的苜蓿遗传图谱有8个连锁群，代表着苜蓿属物种的单倍体染色体组。该遗传图谱是通过对从138个个体的分离群体中收集的89个RFLP、RAPD、同工酶和形态标记的连锁值进行排序构建而成的。这个分离群体是一个F1杂交植株的自交后代，该F1杂交植株源自二倍体（2n = 2x = 16）黄花苜蓿准镰形亚种和二倍体（2n = 2x = 16）蓝花苜蓿天蓝亚种之间的杂交。许多性状的遗传表现出偏分离，表明杂合亲本植株中存在致死基因座。尽管缺乏均匀分离，但仍可确定连锁群，并且跨越> 659厘摩的标记顺序能够明确确定。这个数值与计算得出的苜蓿单倍体基因组大小（1n = 1x = 1.0×10⁹ bp）得出的比例为每厘摩< 1500 kb。
