Bioscience Evidence 2025, Vol.15, No.6, 303-312 http://bioscipublisher.com/index.php/be 307 Rpi-vnt1.1) from the varieties Desiree and Victoria demonstrated complete resistance for three consecutive seasons. The control non-transgenic varieties were quickly destroyed by late blight, further demonstrating the obvious advantages of the gene superposition strategy. Similar manifestations were also observed in field trials in Europe. Materials containing three R genes were not infected by late blight until the end of their growth period, even when diverse and highly virulent pathogen strains were produced locally. Meanwhile, the agronomic traits and yields of these materials are comparable to those of the original varieties, indicating that superimposing multiple R genes does not affect plant growth or yield. More importantly, in years of field trials, the pathogenic bacteria have shown no obvious signs of adaptation or breakthrough of superimposed resistance. 5 Case Study III: Rpi Gene Detection and Field Resistance Analysis of 255 Chinese Potato Germplasm Materials 5.1 Molecular detection of broad-spectrum Rpi genes (R8, RB, RPI-BLB2) Broad-spectrum late blight resistance genes (Rpi genes) such as R8, RB (RPI-BLB1), and RPI-BLB2 are becoming increasingly important in modern potato breeding, especially in countries like China where late blight has long threatened food security. To detect these genes in a large amount of germplasm materials, breeding research generally employs molecular marker techniques specifically targeting genes, such as SCAR markers and PCR detection methods, which can help researchers quickly screen whether hundreds of materials carry key Rpi genes. It is much faster than the traditional method of judging resistance based on field performance (Islam et al., 2024) (Figure 2). In the research of potato resources in China, these molecular detection techniques have been used to systematically investigate whether R8, RB and Rpi-blb2 exist in germplasm materials. Some cultivated varieties and breeding materials in China carry one or more broad-spectrum Rpi genes, and some even coexist with other Rpi genes. The detection of R8 is often achieved through long-fragment PCR or effector protein-based detection methods. RB and Rpi-blb2 are usually detected by specific primers, and sometimes their functions are verified by using the corresponding Avr effector proteins. Figure 2 Harnessing the potato gene pools for enhanced resistance to biotic and abiotic stresses in new cultivars (Adopted from Islam et al., 2024)
RkJQdWJsaXNoZXIy MjQ4ODYzNA==