Biotechnology Department, Alberta Research Council, P.O. Box 8330, Postal Station F, T6H 5X2, Edmonton, Alberta, Canada.
Plant Cell Rep. 1987 Apr;6(2):109-13. doi: 10.1007/BF00276665.
Two cultivars (Heinrichs, Reaver) and two breeding lines (Br1, Le1) from Medicago media were cultured in a media protocol consisting of a high concentration 2,4-D induction step. Regenerants were produced from all four stocks. Representative samples from each regenerant population along with the corresponding control population were cytologically analyzed for chromosomal and pollen abnormalities. While numerical changes in chromosome numbers were found in all regenerant populations, there was considerable variation between the four stock groups. Heteroploidy was observed for both hypo and hyper aneuploid regenerants, but there were no differences in pollen stainability between hypo and hyper aneuploid regenerants and 'euploid' regenerants. Tissue culture regenerants generally produced a lower pollen stainability percent as compared to control populations grown from seeds. Gross and cryptic changes in chromosomes, or hormonal carry over effects or both were considered causes for poor pollen stainability in tissue culture regenerants. Cytological analyses indicate that the cultivar might play an important role in the cytological stability or instability of regenerant populations. Exploitation of this naturally existing situation to produce 'euploid' regenerants for field experiments and to obtain gross cytological stability in somaclones is discussed.
两个栽培品种（Heinrichs、Reaver）和两个育成系（Br1、Le1）从紫花苜蓿在一个含有高浓度 2,4-D 的诱导步骤的培养基中培养。所有四个品系都能产生再生体。从每个再生体群体中选取有代表性的样本以及相应的对照群体进行染色体和花粉异常的细胞学分析。虽然所有再生体群体都发现了染色体数量的数值变化，但四个品系群体之间存在相当大的差异。在低倍和高倍的非整倍体再生体中都观察到了异倍体，但低倍和高倍非整倍体再生体与“整倍体”再生体之间的花粉可染色性没有差异。与从种子生长的对照群体相比，组织培养再生体通常产生较低的花粉可染色性百分比。染色体的明显和隐匿变化、激素残留效应或两者的共同作用被认为是组织培养再生体花粉可染色性差的原因。细胞学分析表明，栽培品种可能在再生体群体的细胞学稳定性或不稳定性中发挥重要作用。讨论了利用这种自然存在的情况来产生“整倍体”再生体进行田间试验，并获得体细胞无性系的总体细胞学稳定性。
