Registration of Two Soybean Varieties Resistant to Asian Soybean Rust in Paraguay

Asian soybean rust (ASR) is the most serious soybean disease in many South American countries, a major soybean producing area in the world. As a countermeasure for ASR, JIRCAS and the Centro Tecnológico Agropecuario del Paraguay (CETAPAR) jointly developed two resistant cultivars, namely, JFNC 1 (JIRCAS y Fundación Nikkei-Cetapar 1) and JFNC 2. These two cultivars have been registered in the National Service of Plant Health Quality (SENAVE) in Paraguay with registration of protection (RNCP) and registration of commercialization (RNCC) nos. 510 and 955 for JFNC 1, and nos. 511 and 1010 for JFNC 2, respectively.

The JFNC varieties have been selected and developed from 2010 by Ms. Miori Uno Shimakawa, Mr. Pedro Iwao Oyama Ezura, and Mr. Christian Espínola from the Nikkei-Cetapar, and JIRCAS Senior Researcher, Dr. Naoki Yamanaka. JFNC 1 and JFNC 2 were bred by introducing three ASR-resistance genes from a highly ASR-resistant soybean line of JIRCAS into two non-GM Paraguayan soybean varieties, namely, Aurora and YG 203 (Name of line: YG00/26-19) via recurrent backcrosses and marker-assisted selection.

The combination of three resistance genes used for this breeding program is effective against the divergent and highly-virulent ASR pathogen in Paraguay. It is expected that these JFNC varieties can contribute in environmental load reduction and improvement in profitability of soybean cultivation by reducing the use of fungicide for the control of ASR.

Figure 1. Morphology of plants and seeds of JFNC 1 and JFNC 2, and the parent varieties Aurora and YG 203.

The JFNC varieties show similar characteristics to the original varieties under normal cultivation environment without infestation of Asian soybean rust.

Figure 2. Growth of JFNC 1 and the parent variety Aurora in rust infested field in Paraguay.

JFNC 1 showed vigorous growth even without sufficient application of fungicide.