Optimizing agricultural industrial system: using molecular markers to improve vegetable hybrid control and variety identification

Bioinformatics technology was used to explore the molecular markers of differences among vegetable hybrid varieties, so as to establish molecular detection techniques that can be analyzed automatically, assist variety identification and improve the control of the purity of the first generation hybrid seeds, and help to sell seedlings more advantageous.

The pace of urbanization has gradually reduced the area of agricultural land, but the demand for food is increasing day by day, coupled with the severe challenges brought by extreme weather to agriculture, Taiwan's agriculture relies on excellent breeding techniques to enable crops under natural conditions. through the successful breeding of hybrids, excellent varieties that can meet the needs of the environment have been bred, bringing new opportunities for agricultural production.

The key to successful breeding lies in seed purity.

"precisely because the success rate of hybridization and the correctness of varieties are very important for seedling sales, we began to think about how to establish more accurate and lower-cost testing techniques to help seedling operators do a good job in quality control." So says Hu Kaikang, an associate professor in the Department of Agronomy at National Taiwan University. He also led a research team on the establishment of molecular detection techniques to improve the purity of hybrid seeds and the efficiency of combinatorial force testing.

It turns out that in the past, after breeding excellent first-generation hybrid varieties of vegetables, seedling operators would entrust professional farmers or seed collection companies to produce hybrid seeds. Regardless of whether the seed was collected in Taiwan or overseas, seed purity is an important quality control index.

Associate Professor Hu Kaikang said, "seed purity is closely related to the goodwill of seedling operators, including the success rate of hybridization and the purity of varieties, in order to determine that there is no external pollen contamination or mixing, and it must be strictly verified before it can be exported, but the traditional field verification method (Grow-out test) is time-consuming and labor-consuming, which not only increases the cost of seed production, but also often leads to disputes between seedling operators and entrusted farmers."

Although crop genomic research and bioinformation technology have developed by leaps and bounds in recent years, the seedling industry often has a low acceptance of R & D results, mainly due to the low repeatability of non-specific molecular marker technology, so there are high technical requirements for experimental operations such as DNA extraction and PCR assembly, which requires a lot of professional manpower in the process of analysis and interpretation, which can not be automated and the cost increases.

Devote yourself to   to improve the efficiency of detection

In the face of this dilemma, after the academic science and technology project of the Council of Agriculture "establishing Molecular Auxiliary seed selection Technology for important vegetable and Fruit crops" in 1999, it finally broke the deadlock and began to introduce high-throughput SNP molecular marker development technology based on next-generation sequencing, and developed a technical platform for large-scale genotype analysis and molecular marker development.

Associate Professor Hu Kaikang said that the first step of the plan is to use high-throughput next-generation parallel sequencing (Next Generation Sequencing, NGS) to obtain a large number of fragments near specific restriction sites for the most important vegetable crops in Taiwan's seedling industry, and then use bioinformatics technology to explore and isolate single nucleotide polymorphism (SNP) molecular markers with differences among individuals. Then, based on the relationship between the genotypes of the molecular markers and the target characteristics (such as disease resistance), the molecular markers which are closely linked to the genes controlling the target characteristics are obtained and provided to seed and seedling operators as assistance in the process of breeding and selection. Because it is directly aimed at locus selection, compared with the traditional selection methods which depend on appearance characteristics, the accuracy of breeding selection is greatly improved and the time required for breeding selection is shortened.

The SNP molecular markers obtained by the development platform established in the molecular assisted seed selection project are highly specific and reproducible, and automatic analysis can be carried out with appropriate instruments. therefore, after the establishment of the development platform, Associate Professor Hu Kaikang has been implementing the biennial committee science and technology plan "establishing molecular detection technology to improve hybrid seed purity and combined force verification efficiency" to meet the needs of the seed and seedling industry. For more than 1000 first-generation hybrid varieties of tomato, cauliflower, watermelon, melon, corn and pepper provided by seed and seedling operators, at least 5000 SNP loci were explored for each crop, from which the core SNP combinations with good introduction design characteristics and can fully explain the differences between varieties were selected, and then according to the variety characteristics, the minimum SNP molecular marker combinations suitable for variety identification and hybridization success rate were selected. As a test standard. These SNP molecular marker combination standards have high reproducibility and can be fully automated, which can help the seed industry to improve the purity control ability of the produced seeds while reducing the labor burden and verification cost, so as to enhance the export competitiveness of the seed industry.

Technology to optimize the Competitiveness of   thick Seedling Industry

"the most important thing, of course, is that the verification can save both time and money," says Associate Professor Hu Kaikang. using molecular markers to test the success rate of hybridization can reduce the cost of each batch of hybrid seeds by 4000 yuan compared with field inspection.

In addition to significantly reducing the cost of seed testing, the accuracy of molecular testing is high, and it can also shorten the verification time to within one month and accelerate the shipping speed, which can be said to greatly reduce the cost of seed storage and marketing, and fully improve the product quality and international competitiveness of seed and seedling manufacturers.

Associate Professor Hu Kaikang believes that in the future, whether technology transfer is accepted by credible testing operators or joint investment by seed and seedling operators to set up testing laboratories, they can inject abundant energy into the leap of the seed and seedling industry and optimize agriculture, and embrace a new future.

Related information

For more details on the R & D results of this project, please contact Mr. he of Agricultural Science and Technology Research Institute, a legal person of the consortium, Tel: 03-5185049, email: 1072086@mail.atri.org.tw