1923 after receiving his bachelor's degree in Tsinghua, Li Xianwen immediately went to the Horticulture Department of Purdue University in Indiana, USA for further study. 1926 obtained a master's degree and entered the graduate school of Cornell University. He studied under the internationally renowned maize geneticist R.A. Emerson, focusing on genetics. The establishment and development of maize genetics research focused on the research group composed of Emerson and his students. Li Xianwen, the only China student in this research group, cooperated with his tutor Emerson to study the inheritance of maize dwarf traits. In the field of international genetics at that time, Emerson and others kept pace with T.H. Morgan's research on the genetics of Drosophila. At Cornell University, Li Xianwen got his wish and studied harder. Every summer, he and more than 10 teachers and students of the maize genetic research group wear clothes for field work, carrying a large number of paper bags and knives for pollination, just like a group of farmers working in the fields. They should not only master the flowering period of corn, but also complete a lot of pollination work; It is really hard work to make careful field observation and make detailed records.
This group of colleagues gradually became famous geneticists, including G.W. Beadle, who lived in harmony with Li Xianwen and had the deepest friendship, and won the 1958 Nobel Prize in Physiology or Medicine for putting forward the theory of "one gene and one enzyme". G.F. Spragueb B. mcclintock, the former chief corn breeder of the United States Department of Agriculture, was the first to discover transposons, and won the Nobel Prize in Physiology or Medicine in 1983.
Cornell University's well-equipped laboratory, well-collected library, sincere cooperation in scientific research and strong academic atmosphere of frequent and enthusiastic discussion on scientific issues deeply infected and inspired Li Xianwen, strengthened his belief in creating an intellectual atmosphere for such academic research in his own country in the future, and laid a solid foundation for his academic career in plant cytogenetics research in the future. /kloc-received his doctorate in 0/929 and returned to China in 2008. After returning to China, Li Xianwen successively served as a professor in the Agricultural College of Central University, Northeastern University, Peking University, Henan University, Wuhan University and Taiwan Province Provincial University, mainly teaching courses such as plant cytogenetics. During his decades of teaching career, he is famous for his profound knowledge, serious attitude, rigorous scholarship and being good at teaching students in accordance with their aptitude. He pays attention to cultivating research-oriented talents through experimental observation of genetics and specific practice of genetic breeding.
In the1930s, when Li Xianwen was teaching in the Agricultural College of Henan University, there was a sincere and upright Meng He as his assistant. He always works together, from the field to the laboratory, no matter what kind of work. They are not much different in age. In that difficult environment, they can always cooperate with each other and become mentors. They lived in harmony for decades and never complained to each other.
Li Xianwen is famous for his tough style, and he also lets his assistants do it themselves, both with their hands and brains. He will learn this fine style from his mentor Emerson, and ask his students and assistants to set an example by example. When he was teaching at Wuhan University, Professor Feng of Wuhan University once recommended Li Xianwen as his rice teaching assistant. As soon as he heard that he was from Suzhou, he refused, thinking that young people in weak countries must not bear hardships and stand hard work. After some explanation, he is willing to give it a try. Wait until a few years later, when Li Xianwen mentioned this matter again, he said, people should not judge a book by its cover. Li Xianwen is frank and straightforward, and sometimes it is not easy to understand. But after getting along with him for a long time, you will understand that he has a sense of justice and is helpful. During his work in Taiwan Province Institute of Botany, in order to make the scientific career successful, he often rode a bicycle and personally went to various agricultural colleges to recruit aspiring young people. He also set up individual scholarships in Taiwan Province Provincial University to reward the advanced and encourage the backward.
According to statistics, during Li Xianwen's decades of teaching and research career, more than 27 students have obtained doctoral degrees directly trained by him and recommended to go abroad for further study. Specializing in molecular biology, cytogenetics, population genetics and other research fields. Li, Bao and others are famous geneticists. They have cooperated with Li Xianwen for a long time and achieved important results. Li Xianwen has a wide range of academic research fields. 1932, when he went to the Agricultural College of Henan University to teach, he was unwilling to give up theoretical research despite the difficult conditions. We have done the experiments of trait inheritance and interspecific hybridization of wheat, corn, millet and other crops, as well as the hybridization experiments of pumpkin and pumpkin. In wheat breeding, he personally sowed and covered the soil, making the field work of breeding clear at a glance. When studying the flowering of millet, he went to the field every 1 hour during the day and every 2 hours at night. At night, lanterns are used to illuminate flowers and make records as usual. At first, he used statistical methods to do research, and later he did research on plant cell inheritance.
1In August, 935, Li Xianwen came to teach at Wuhan University, which was an ideal place for him to display his theoretical research talents. He and his assistant first discovered the mutant with abnormal development of maize pollen and made cytological observation. They also successfully crossed wheat and rye for the first time. Because they want to move to Sichuan, they have to move this hybrid seedling from the ground to a small flowerpot, take it with them, go through Yichang, Jiangjin and Chongqing to Chengdu, and then plant it in a greenhouse. The young spike was fixed before flowering and cytological analysis was carried out to clarify the relationship between abnormal chromosome behavior and pollen and ovule abortion. In Wuhan University, although he is the head of the agricultural department, he often goes down to the fields alone, wearing shorts and deep water, and conducts field observation and selection of rice genetics and breeding in extremely hot temperatures and mosquito bites. That is, when he continued the interspecific hybridization experiment of millet, he found "tetraploid" from a pearl millet. During this period, he went to Imperial University of Kyushu, Japan to study sericulture improvement at his own expense, and discussed the somatic genetics of silkworm with the internationally renowned geneticist Yoshimo Tanaka.
1937, War of Resistance against Japanese Aggression broke out in an all-round way, and Li Xianwen came to Sichuan with the westward movement of the National Government. From 65438 to 0938, at the invitation of Sichuan Agricultural Improvement Institute, he served as the director of grain crops group, and later served as the director of Sichuan rice and wheat improvement farm, responsible for the research on grain yield increase and the implementation of verification plan in rice operation. At that time, he had successfully planted an excellent rice variety in Hechuan, Mianyang, so he tried to popularize it and the effect was very good.
During his stay in War of Resistance against Japanese Aggression, Li Xianwen was invited to preside over the rice and wheat experimental field of Sichuan Agricultural Reform Institute. Although almost all his time is entangled in administrative affairs and field trips, as long as he has time, he will go to a humble laboratory of 6 ~ 7 square meters and continue to devote himself to systematic research on cytogenetics of crops such as wheat and millet together with his collaborators Li and Bao. They have made many original research achievements and published many research papers in the aspects of plant polyploidy induced by colchicine, distant interspecific hybridization and its evolution of millet, chromosome-associated disappearance genes of wheat and genetic analysis of wheat dwarf traits.
1944, Institute of Botany, Chinese Academy of Sciences was formally established, with 8 laboratories. Among them, Cytogenetics Laboratory was the only official genetic research institution in China at that time, and Li Xianwen was the director of the laboratory and presided over the research work. He planted wheat and other crops on half an acre of land cultivated by himself. He and his collaborators have successively devoted themselves to the study of the relationship between chromosomes and traits of wheat, millet, sugarcane, corn, sorghum and related species, such as "Chromosome variation of hybridization between wheat and Setaria viridis" and "Relationship between spike type change of wheat and the number of genetic factors (haploid, apoplast, polyploid, etc.)". ), "sorghum heterosis" and "sugarcane cytogenetics".
The research group headed by Li Xianwen systematically concluded that Setaria originated from Panicum, and there are four polyploid species in Panicum, with chromosome numbers (n) of 9, 18, 27 and 36 respectively, and the evolution of these species follows the procedure from low to high. However, if we analyze the morphological characteristics and ecological habits of nine millet varieties collected, such as the number of bristles, the shape of inflorescences and the number of branched spikelets, their evolutionary order is obviously inconsistent with the above procedures. If we combine the two, and according to the results of some interspecific hybridization, we can reasonably describe the evolutionary program diagram. The diagram shows that the evolutionary position of cultivated millet is in the middle, its close ancestor is S.Viridis, and another wild species, S.faberii(n= 18), is autotetraploid, at least one of which is the genome of cultivated millet or Setaria viridis. Faberii species and their hybrids are sterile, but a new species with n=27 can be obtained by doubling colchicine.
In the experiment of interspecific hybridization of Gramineae plants, he and his colleagues found many unusual things about interspecific hybridization. For example, failure to form a spindle during cell division will lead to asymmetric chromosome movement, and as a result, it is possible to form a reconstructed nucleus with undiminished chromosomes. These findings inspired him to explore the future research on improving rice seeds through distant hybridization.
After years of painstaking research, Li Xianwen and others have accumulated a set of materials of wheat haploid, apoplast and polyploid chromosomes, as well as various lines of sexual hybridization between millet and Setaria viridis, which provided a large number of original materials for crop genetics and breeding. These rare and precious experimental materials were observed by Xia Zhen 'ao, who worked in Cytogenetics Laboratory of Institute of Botany, Chinese Academy of Sciences, in 1960s and 1950s, and some new research materials were obtained. However, they all disappeared because of frequent political movements at that time. From 65438 to 0948, Li Xianwen cooperated with the Sugarcane Research Institute of Taiwan Sugar Company to carry out practical research on sugarcane cytogenetics, breeding and cultivation. Taiwan Sugar Company specially sent people to inspect and invited him to study sugarcane cytogenetics at Pingtung Sugarcane Breeding Farm in Taiwan Province Province. In June165438+1October of the same year, Li Xianwen and Li went to Pingdong Sugarcane Breeding Farm in Taiwan Province Province to conduct research and guidance on sugarcane genetics and breeding.
From 65438 to 0949, Li Xianwen served as a consultant of Taiwan Sugar Company, specifically guiding the improvement of sugarcane varieties. In order to find out the family background of sugarcane varieties, he often went to the farm, went down to the sugarcane field with the staff and looked at the varieties, and his footprints were almost all over Taiwan Province Province. While working on sugarcane improvement, he also took a leisure to count the chromosome number of sugarcane varieties, which is enough to reflect his persistence in plant cytogenetics research.
In 1952, he discovered the N:Co3 10 variety introduced from South Africa, which was proved to have the advantages of high yield, high sugar content, disease resistance, wind resistance and salt tolerance. Later, he organized the popularization and expanded it to 8 1000 hectares in 1956. At the same time, he established the ratoon breeding system of sugarcane, and changed the two-year system into a four-year system, thus giving Taiwan Sugar Company a new life. At that time, 70% of Taiwan Province's foreign exchange came from the export of sucrose. With the popularization of this improved variety, the economy of Taiwan Province Province has stabilized. Therefore, farmers in Taiwan Province praised Li Xianwen as "Li" and "Sugarcane God".
65438-0955, Li Xianwen was appointed as the director of the preparatory department of Institute of Botany, Chinese Academy of Sciences. He began to train professionals, actively equipped laboratories, established excellent libraries, and emphasized the creation of academic research atmosphere. From 65438 to 0962, he became the director of the reconstructed plant research institute, and determined that the focus of his research work was rice cytogenetics, radiation mutation breeding and so on. In just a few years, the Institute has bred excellent dwarf rice lines through mutation breeding, so the International Atomic Energy Agency held an international seminar in Taiwan Province Province.
From 65438 to 0965, Li Xianwen was the director of Taiwan Province Life Research Center. From then on, he can really plan the development of biological science in Taiwan Province Province according to his early ideals, showing his outstanding scientific research ability and organizational ability. In order to promote biological research and education in Taiwan Province Province and introduce the theory of modern life science, he organizes summer seminars every year from 1964 to 1969, and invites famous foreign scholars to give lectures in Taiwan Province Province for eight weeks. From 1967 to 1968, he also organized seminars on new progress in biochemistry and genetics. 1973, Li Xianwen retired due to poor health, but he still participated in research endlessly, kept in touch from time to time, and constantly encouraged and supervised his colleagues. 1died of heart disease on July 4, 976 at the age of 75.
Li Xianwen has done a lot of original work for the development of genetics in China with the spirit of seeking truth from facts all his life. Especially in China in the1930 ~1940s, due to the continuous civil war, the scientific research conditions were not guaranteed. Li Xianwen went back and forth to several universities to do research work, and often had to bear the pain and sacrifice to start a new stove. He once said with emotion: "The improvement of any kind of crops, taking rice and wheat as an example, will take at least five or six years, and how can it achieve results if the environment is changed so frequently?" Thus solemnly put forward the importance of the word "longevity" to biological scientists. He closely combined genetic research with breeding practice and summed up three experiences: first, he can raise; The second is cooperation; The third is to use both hands and brains. He once said: "Some people get surprisingly good grades when studying abroad, but they give up scientific research after returning home. Students naturally don't study when they see that the teacher doesn't study. This phenomenon will be passed down and scientific research will never achieve anything. " In such a difficult period, Li Xianwen didn't trust books easily, tried hard to obtain first-hand information, and took on "rough work" with real hands, which made his success real, without a lot of ambiguity of "genius", and better reflected the burning brilliance of his quality as a scientist.
Starting from 1933, Li Xianwen published the first research paper on plant cytogenetics by China scholars in the American Journal of Genetics. In the following 40 years, he and his collaborators have written and published more than 100 research papers, especially the experimental research on genetics and breeding, which is admirable and is known as a plant cytologist with high reputation in the world.
1948 was named the first academician of academia sinica (at that time, he was the only scholar engaged in plant cytogenetics research among 25 academicians of the biological group), and he was an academician of the institute a few years ago. In the same year, the International Society of Genetics invited Li Xianwen to attend the Eighth International Congress of Genetics, but he didn't make it because the war didn't raise enough funds. After that, he attended the 9th 10,1/international genetics congress and was elected as the vice chairman of 1 1 international genetics congress. In addition, he also participated in all previous Pacific scientific conferences and international botany conferences.