We read with great interest the recent article ‘Some pioneers of European human genetics’ by Peter Harper.1 This comprehensive review is very informative and highly appreciated. But a somewhat misleading statement needs to be reconsidered. Harper regarded Lysenko as a fraudulent agronomist. We disagree with him on this fundamental point. We are thinking that he was greatly misled by Medvedev’s book, The Rise and Fall of TD Lysenko,2 which he cited in his article. It should be noted that there are many misleading statements in this book. For example, in chapter 8, Medvedev argued against the validity of Lysenko’s work on plant graft hybridization, and pointed out that ‘serious and precise experiments by many scientists have failed to prove the possibility of transfer of hereditary stable properties from stock to scion’,2 thus regarding graft hybridization as Lysenko’s fraud. To our knowledge, it is Darwin who put forward the concept of graft hybridization. He described many cases of graft hybrids, and considered it to be special importance for understanding the mechanism of inheritance and variation. Later, Michurin invented the so-called ‘mentor-grafting’ method, which greatly enhanced the induction of graft hybrids. Lysenko not only recognized the existence of graft hybrids, but also applied the method of graft hybridization to the practice of plant breeding. Over the past several decades, extensive experiments on graft hybridization have been carried out and numbers of new crops and varieties were developed by grafting, indicating that graft-induced variant characteristics were stable and inheritable.3 Now it has been proposed that graft hybridization may serve as a mechanism of horizontal (or lateral) gene transfer. Thus, it is not proper to continue to regard Lysenko as a fraudulent agronomist.

Harper considered the inheritance of acquired characteristics as the defining feature of Lysenkoism, and referred to it as false science.1 Actually, the inheritance of acquired characters has been the subject of passionate debate and heated controversy since the days of Lamarck. Even Darwin accepted the Lamarckian inheritance of acquired characteristics as an established fact, and had assumed that it was of importance in evolution.4 He considered natural selection, the inheritance of acquired characteristics and mutation as three factors influencing evolution. It is true that Lysenko was a keen supporter of the inheritance of acquired characteristics. He claimed that the environmentally induced changes were transmitted to the progeny by demonstration of the conversion of spring wheat into winter wheat and vice versa. In recent years, there has been a substantial body of reliable experimental evidence for the inheritance of acquired characteristics.4, 5 Lysenko’s work on the conversion of spring wheat into winter wheat can be explained by transgenerational epigenetic inheritance.6 Now it seems that Lysenko was not wrong in believing the inheritance of acquired characteristics.

Harper also mentioned Lysenko’s errors and crimes, as well as the death of numerous researchers in genetics.1 The impression which one gets from reading this paragraph is that Lysenko was responsible for the death of these geneticists. We fear that this view is too one-sided and not supported by historical evidence. It is true that Lysenko disputed with Vavilov and many other geneticists on some genetic viewpoints. But we must know that Lysenko was a leading Soviet scientist in agriculture and genetics. He was not the NKVD chief, thus he had no power to arrest geneticists. Lysenko himself repeatedly maintained that he was not personally responsible for Vavilov’s arrest and death. He recalled that the investigator of Vavilov had come to see him and asked: ‘What can you say in general about the wrecking (spying, counterrevolutionary) activities of Vavilov?’ Lysenko replied: ‘There were and are some differences of opinion on scientific matters between myself and Vavilov, but I have no knowledge of any wrecking activities of Vavilov’.7 In addition, Haldane, one of the towering figures of twentieth century biology, also denied that Lysenko had been responsible for Vavilov’s arrest and death.8

It is not our intention to minimize Lysenko’s mistakes and to exalt his contributions, but we must try to see things in their right proportion. Actually, some of Lysenko’s work had a certain scientific merit, which was recognized internationally. For example, it was Lysenko who coined the term vernalization, which is now still an extant scientific term and frequently appears in Nature, Science, Cell and many prestigious journals. In addition, some of Lysenko’s work was highly praised by world-famous scientists. For example, in early 1930s, Vavilov repeatedly place a high value on Lysenko’s contributions to science and agricultural production. As he said, ‘Lysenko is a careful and highly talented researcher. His experiments are irreproachable’.9 In 1964, Haldane made an objective comment: ‘In my opinion, Lysenko is a very fine biologist and some of his ideas are right’.10 Of course, we also recognize that some of Lysenko’s ideas were wrong and badly wrong. His biggest mistake was mixing science and politics. He regarded Mendelian genetics as ‘bourgeois science’ and forced Soviet geneticists to accept Michurinism, for which he got a bad reputation.