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From the 1920s onwards, experts from Nanjing Agricultural University began to collect a variety of bizarre beans "seeds." After running through most of China's rural areas, they finally collected more than 15,000 varieties of soybean seeds and built the world. The third largest “soybean resource bank†will be able to leave the “fire†of the soybean civilization and reproduce more excellent “offspringâ€. Yesterday, the reporter walked into this mysterious library of soybean germplasm resources.
Nannong has a legume "genuine treasure house"
In the soybean germplasm pool, the low temperature of minus 5 degrees Celsius is maintained all the year round. The iron racks that line the ceiling form a "little home" for beans, dazzling glass jars, Huai'an big green beans, and Longnan cat's eye beans. Zhaotong Tea Bean ... 15,000 soybean varieties settled here.
According to the staff, in this germplasm resource pool, there are more than 1,000 wild germplasm resources, more than 1,000 foreign soybean germplasm resources, and more than 3,000 special soybean germplasm resources in Jiangsu - using them to make more flavorful Tofu, soy milk, bean sprouts, edamame, strange flavor bean products.
The reporter saw that some of the more than 15,000 soybeans have the same name, but the numbers are different. Zhao Tongyi, the soybean germplasm resource bank of Nanjing Agricultural University, said that there are many people who call it "Li Si," but each one Li Si is an independent person. People will use the ID number to distinguish them. In the genebank, they are also identified by numbers. They come from different regions. In fact, genetic traits are different and they belong to experts. Different germplasm specimens.
More than 90% of the species have now been abandoned. Zhao Tuanjie told reporters that the collection of varieties of soybean germplasm resources at the Nanjing Agricultural University has been going through more than 80 years. Since the 1920s of the last century, Professor Wang Hao has cultivated a highly productive Jinda 332 soybean variety. At that time, it began to collect a wide range of legume resources across the country.
In the 1950s, under the leadership of academician Ge Yan, the Soybean Germplasm Bank at Nanjing Agricultural University increased the collection of “farmer varieties†and mobilized teachers to use business conditions to penetrate rural areas and use the exchange conditions. Collecting, and calling students from all over the country to collect the variety of beans cultivated in the villages and villages.
Zhao Hejie said that among the more than 15,000 soybean varieties collected at the South Agricultural Soybean Germplasm Resource Center, many varieties are known by “lesser peopleâ€. They are only planted on a very small scale for generations, and some may even be only a few. Ethnic villages. Many varieties are not named, so the experts will name these varieties of soybeans by collecting the names of villages, villages, and even collecting people. Even the analysis of the shape of soybeans, such as Hanyuan Zhong Enhai white beans, generous This is the case with flat top beans.
According to the staff, more than 90% of the more than 15,000 farmer varieties collected have already been abandoned. If they do not collect their germplasm resources, the genes of this species may become Lost forever, so this gene bank is like "Noah's Ark" of the soybean resource.
5 Years of "Full Update" of the Soybean Resource Bank
Soybean seeds, preserved in their natural state, are actually very difficult because they contain very high oil and protein, and they can go oily as they grow over time. As a result of fission, the seed will deteriorate and fail to germinate.
Zhao Tongjie told reporters that under normal circumstances, the seeds of soybeans can only be kept for one year, and for the collection of legume varieties collected from the germplasm resource bank of South Agriculture, the seeds should be selected first, and the viability test should be conducted at the same time. It is dehydrated and dried, and finally stored in an environment of minus 5 degrees Celsius to minus 15 degrees Celsius, and the moisture content of the soybean variety is maintained at about 8% by means of a drying machine and a silicone sealer. However, even so, the variety of beans collected can only last about five years.
Therefore, the number of legume seeds of experts is about 3,000 per year for artificial breeding and breeding, so as to ensure the seed “freshness†in the germplasm resource pool. To calculate it, about 5 years, 15,000 seeds will be counted. A complete update will be completed.
Ten years to find rare "sterile genes"
In the eyes of experts, the germplasm resource pool of plants is a rare treasure trove of genetic resources because these germplasm resources are formed under natural ecological conditions over thousands of years and contain a variety of genes that can be used - - insect-resistant, disease-resistant, drought-resistant, salt-tolerant and so on. What the experts need to do is to find these high-quality genes from tens of thousands of seeds. One of the important genes is to look for "sterile genes" because it is extremely important for soybean hybridization.
Zhao Tuojie said that hybrids have been widely used in the world's major food crops and have played an epoch-making role in the development of agricultural production. For example, hybrid rice, which people are familiar with, has made a tremendous contribution to the problem of human settlement. For a long time, the world soybean yield has been increasing slowly. Scientists from various countries have made great efforts to solve the problem of low yield of soybeans and seek methods for exploiting hybrid superiority. However, due to the special nature of soybean self-pollination crops, the use of hybrid superiority has become a fortress difficult to overcome. The experts from the Soybean Germplasm Bank of Nanjing Agricultural University spent a full decade of “dry experiments†and finally found two germplasm materials with rare genetic susceptibility genes for soybeans. One of them was also derived from wild soybeans. This provides great possibilities for soybean "hybridization".
Establishing "Generation Lineage" of Cultivated Soybeans
In order to cultivate new varieties, introduce new achievements, and find the genetic basis of soybean cultivars, experts studied the geographical origin, characteristics and pedigrees of 651 soybean varieties that were bred from 1923 to 1995 in China, and were traced back to 348 ancestral parents. Derived spectrum trees of 348 ancestral parents.
On this basis, based on the nucleus and cytoplasmic families, genetic basis, direct parental types and other types and geographical origins and combinations of Chinese soybean varieties, 75 core ancestral parents of soybeans were summarized. They were used for 1923-1995. The nucleus and quality genetic contribution rates of the cultivars reached 68.99% and 71.43%, respectively, from which they nominated 38 of the most important ancestral parents.
The South is the Center for Genetic Diversity of Soybeans. In addition to the pedigree of pedigrees for planting soybeans, the experts also analyzed the fingerprints of soybeans collected using genetic techniques. As a result, experts found that the wild soybeans and cultivated soybeans in the south Diversity is higher than in the North.
Therefore, it is speculated that southern China may be the center of genetic diversity in China's wild soybeans. The genetic distance between the different populations of wild soybeans is the nearest to the cultivation of soybeans in the south, the farthest in the northeast, the Huanghuai population between the two, and cultivated soybeans originated in the south. The original wild population.
Note: 90% of soybean farm varieties are disappearing
Note: 90% of the soybean varieties in the wild facing the disappearance of wild soybeans, containing rare infertility genes; cultivated black beans naturally resistant to leaf mosaic disease, has a natural disease-resistant genes; the weight of round 100 drums of large black beans unexpectedly There are 80 grams, which is a little less than a coin of a dime. The smallest wild soybean 100 has a weight of less than 1 gram. It weighs only 1/80 of that of a large black bean and it looks like ordinary Nannong 493-1 to Nannong 1138-2, turned out to be a breeding master, cultivated 27 strange "children"...