Uptake of excess iron by lowland rice plants causes iron toxicity, which is a major problem in the affected areas. This study investigated molecular diversity, genetic structure, and marker–trait associations for tolerance to iron toxicity in a panel of germplasm lines using microsatellite markers. The studied population showed a moderate to high degree of genetic diversity, as revealed by the estimated molecular diversity parameters and principal component, cluster and box plot analyses. The landraces Mahipal, Dhusura, Dhabalabhuta, Champa, Sunapani and Kusuma were identified as suitable for cultivation in the areas affected by high iron levels. The landraces Dhusura, Kusuma, Kendrajhali, Ranisaheba, Panjabaniswarna, Mahipal, Dhinkisiali, Champa, Kalamara and Ratanmali, which showed low scores for tolerance, were considered good donors for iron toxicity tolerance improvement programs. Utilizing STRUCTURE software, a total of four genetic structure groups were detected in the panel germplasm of lines. These structural subgroups exhibited good correlations among their members for iron toxicity tolerance and other yield-related traits. Marker–trait association analysis validated the reported iron toxicity tolerance QTLs qFeTox 4.2 and qFeTox 4.3, which are useful for marker-assisted improvement. A new QTL, qFeTox 7.1, located on chromosome 7, was detected as controlling iron toxicity tolerance in rice.

This study assessed the seasonal dynamics of sucking insect pests and their natural enemies during the kharif season of 2021 at the Regional Research and Technology Transfer Station in Bhawanipatna, Odisha, from 30th to 52nd Standard Meteorological Weeks (SMW). Jassids (Amrasca biguttula biguttula) showed low initial numbers but increased significantly from the 34th week, peaking at 14.57 to 14.98 jassids per 3 leaves in the 42nd and 43rd weeks before declining, with a mean of 5.59±4.59 jassids per 3 leaves. Aphid (Aphis gossypii) populations peaked at 38.43 aphids per 3 leaves in the 34th week but then dropped to negligible levels, averaging 7.53±11.58 aphids per 3 leaves. Whiteflies (Bemisia tabaci) remained consistently low, peaking at 2.42 whiteflies per 3 leaves in the 46th week, with a mean of 1.00±0.68. Thrips (Thrips tabaci) increased from the 36th week, peaking at 10.22 per 3 leaves in the 38th week, with a mean of 3.01±3.42. Natural predators, including ladybird beetles, spiders, and green lacewings, peaked at 3.05 per plant in the 35th week, averaging 1.11±0.95. Weather factors significantly impacted pest and predator populations: minimum temperature correlated positively with jassids (r = 0.432) and predators (r = 0.673), while evening humidity correlated positively with jassids (r = 0.497) and thrips (r = 0.405). Rainfall significantly correlated with thrips (r = 0.582).