王钦美，张志宏，崔建国

(1.沈阳农业大学园艺学院，辽宁 沈阳 110866； 2.沈阳农业大学林学院，辽宁 沈阳 110866)

无性繁殖植株的生理年龄
——由端粒长度引发的思考

王钦美1,2，张志宏1*，崔建国2

(1.沈阳农业大学园艺学院，辽宁 沈阳 110866； 2.沈阳农业大学林学院，辽宁 沈阳 110866)

植物细胞中端粒长度随年龄的变化远比动物复杂，可分为不变组、延长组、缩短组和循环变化组。尽管如此，端粒长度亦可用于预测植物年龄。在植物组织培养过程中，端粒长度也会变化。故无性繁殖植株生理年龄值得思考和研究。本文基于端粒长度探讨了无性繁殖植株生理年龄。认为生理年龄较老供体可能会无性繁殖出“小老头”无性系，端粒长度可能成为预测植物材料无性繁殖能力和愈伤组织再分化能力的有效新指标，老树复幼和端粒长度的关系是一个很好的研究课题。此外，提出了植物愈伤组织需要足够的时间来抹除外植体“痕迹”的新观点。关于植物无性繁殖过程中的端粒长度，有很多问题亟待研究和探索。

端粒；离体快速繁殖；扦插；嫁接；生理年龄

Abstract: The change of telomere length during aging of plant cells has been found to be much more complicated than that in animals. It can be divided into the invariant group, the prolongation group, the shortening group and the circle change group. Nevertheless, the age of plants can also be predicted based on telomere length. Moreover, the telomere length can change during plant tissue culture. Thus, the physiological age of asexual plants is worth to be studied. In the article, the physiological age of asexual plants is discussed based on telomere length. It is concluded that the older donor might produce clone with small body but old physiological age, telomere length might be a novel reliable indicator for assessment the ability of both asexual propagation and callus redifferentiation of plants, the relationship between old-tree reinvigoration and telomere length might be a good research project. Furthermore, it is proposed that plant calli need enough time to erase the traces of the explants. Many problems about the telomere length during asexual propagation of plants are urgent to be researched and explored.

Keywords: telomere;invitrorapid propagation; cutting; grafting; physiological age

端粒是位于真核生物染色体末端的核蛋白结构，它由端粒DNA重复序列、组蛋白八聚体和蛋白端粒帽子共同形成[1-2]。大多数陆生植物的端粒DNA是拟南芥式的7核苷酸重复(TTTAGGG)n[3]，但是也有人类式重复等很多例外情况存在(表1)[2]。端粒能够保护线性染色体不被内源核酸酶损伤，避免线性染色体被误识为未配对的染色体断片[2]；端粒与细胞分裂、细胞衰老及寿命有着密切的联系[4]。……