The deployment of varietal resistance remains one of the most effective, economical, and environmentally sustainable strategies for managing bacterial leaf blight (BLB) and bacterial leaf streak (BLS). Two major rice diseases are caused by Xanthomonas oryzae pv. oryzae (Xoo) and X. oryzae pv. oryzicola (Xoc), respectively. Previous screening identified the rice variety SK20‐28 as highly resistant to Malian isolates of both pathovars. This resistance is conferred by a novel variant of the Xa1 gene (Os04g53120), characterized by an extended leucine‐rich repeat (LRR) domain and enhanced recognition specificity toward local X. oryzae pathotypes. To validate this resistance and evaluate the agronomic adaptability of SK20‐28 under real farming conditions, a field trial was conducted in the managed lowlands of Banfara, Mali, alongside the local check variety NERICA‐L2 and three elite varieties (ARICA‐R1, DKA‐M7, and Shwetasoke), using a randomized complete block design. The results confirmed the exceptional and durable resistance of SK20‐28 to both BLB and BLS. This variety also achieved the highest grain yield (4.9 t ha −1 ), representing a 35% increase compared with the local control. Highly significant differences ( p < 0.001) were observed among varieties for yield, plant height, fertile tiller number, and disease resistance. Broad‐sense heritability estimates ranged from 71% to 96%, indicating strong genetic control of key agronomic traits. Overall, these findings validate the functional efficiency of the Xa1 variant carried by SK20‐28 and highlight its potential for sustainable rice production in the managed lowlands of Mali, as well as its value as a resistance donor in rice breeding programs.
Tekete et al. (Thu,) studied this question.