Evaluation Of Agronomic Traits And Adaptation Of Some Promising Salt Tolerant Rice Lines/Varieties Growing In The Coastal Areas In Thanh Hoa Province, Vietnam

Abstract

Rice (Oryza sativa L.) is the main food in Vietnam and plays an important role in economic activity in this country. However, rice yield and growing areas are adversely influenced by the threats of the devastation caused by the rise of sea level. This study aimed to evaluate the salt effects in field experiments of 19 promising salt tolerance rice lines/varieties carrying QTL/Saltol, which were selected from the BC₂F₅ breeding combination between FL479 and Bac Thom 7 (BC7). The field experiments were conducted in two consecutive seasons at three saline-affected rice growing areas, including Nga Son, Hoang Hoa and Quang Xuong districts, Thanh Hoa province. The results showed that among those promising rice lines, the HL15 line had the best yield components in all experimented sites, and good agronomic traits with short plant height and shorter growth duration than the BC7 variety (115-117 days) in the spring season and 102-103 days in the summer season, respectively. All tested had the same level of pest resistance/infection as the control variety BT7 under production conditions using pesticides including HL1, HL13 and HL15, which were mildly infected with the bacterial leaf blight, while HL15 variety showed high resistance to pests and diseases. Moreover, the HL2, HL15 and HL19 lines had scored 3, equivalent to FL478 (tolerant), and the survival rate was over 85% compared with the control variety. Overall, our findings showed that the promising purebred variety HL15 had a range of good agronomic characteristics, resistance to major pests and diseases, high yield potential and salinity tolerance of 6‰. The HL15 variety was renamed as SHPT15 and continued to conduct procedures to recognize it as a new rice variety.