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【目的】探究异染色质纽在玉米、类玉米及其杂种后代染色体上分布的特点及遗传稳定性。【方法】利用组成玉米异染色质纽的180-bp重复序列和TR-1元件对二倍体多年生类玉米(Zea diploperennis,DP)、玉米自交系330及其远缘杂交后代异源种质纯系540的有丝分裂中期染色体进行荧光原位杂交,观察杂交信号在3个材料染色体上的位置、强弱及分布数量。【结果】玉米自交系330的第2、3、5、6、7号染色体长臂的近末端区显示较强杂交信号。DP的第2、3、5、6、7、8、9号染色体的长臂末端检测出异染色质纽,其中2号染色体在短臂的末端也检测到异染色质纽杂交信号。杂交后代540的第2、5、7染色体长臂近末端区检测到较强的杂交信号;3个材料的第6染色体短臂末端的随体上均显示强杂交信号。【结论】玉米大部分异染色质纽成分不能稳定遗传,其表现出来的多态性可以作为鉴定玉米和类玉米杂种后代的细胞学标记。
【Objective】 To investigate the distribution and heterosis of heterochromatin on chromosomes of maize, maize and their offspring. 【Method】 The diploid perennial maize (Zea diploperennis, DP), maize inbred line 330 and its allied heterotic germplasm were crossed with 180-bp repeats and TR-1 elements that constitute heterochromatin of maize. Fluorescence in situ hybridization was performed on metaphase chromosomes of 540 lines to observe the position, intensity and number of hybridization signals on the chromosomes of three materials. 【Result】 The results showed that the near-terminal region of the long arm of chromosomes 2, 3, 5, 6 and 7 of maize inbred 330 showed strong hybridization signal. Chromosomes 2, 3, 5, 6, 7, 8 and 9 of DP detected heterochromatin at the long arm. Chromosome 2 hybridized with heterochromatin at the end of chromosome 2. The strong hybridization signal was detected in the proximal end of the long arm of chromosomes 2, 5, and 7 of the hybrid progeny 540. The strong hybridization signal was observed on the end of the short arm of chromosome 6 of the 3 materials. 【Conclusion】 Most heterochromatin components of maize can not be inherited stably, and the polymorphism can be used as a cytological marker to identify progeny of maize and maize hybrids.