Plant Science Research, Vol. 44, 2022

Yield variability of Sub1 introgressed late-duration rice varieties of Odisha as evidenced by OJIP transient analysis

In current climate changing environment, selection of suitable rice genotype is very important for sustainable rice productivity. Genetic diversity of seven late-duration rice (Oryza sativa L.) varieties (Swarna, Swarna Sub1, TDK, TDK Sub1, Bahadur, Bahadur Sub1 and a check variety Mrunalini) of Odisha were analyzed for yield attributing traits and photosystem II activity related to yield.100-grain weight was significantly high in TDK (2.95 g) with low grain number per panicle and TDK Sub1 (2.89 g) with significantly high fertile grain number. Significantly high harvest Index was recorded in TDK Sub1 with second highest plot yield of 49.39 q ha-1 which was 1.26-fold more than check variety Mrunalini. However, the highest yield was obtained in TDK (1.33-fold) followed by Swarna (1.14-fold) as compared to Mrunalini. Sub1 gene introgression yielded better in Bahadur Sub1 which was not found in Swarna Sub1 and TDK Sub1. A significant positive correlation was noticed between 50% days to flowering vs. grain yield per plant (r = 0.96) followed by panicle number (r = 0.94). Plot yield was highly correlated with panicle length, panicle number, fertile grain percentage, flag leaf length, flag leaf area and grain yield per plant. Significant alteration of chlorophyll a florescent activity was noticed among the studied genotypes. O-J-I-P analysis revealed variable fluorescence intensity at ‘J’ and ‘I’ transient point was significantly higher in TDK and TDK Sub1 as compared to check variety Mrunalini which corroborate with highest yield among the studied varieties.The comparatively low productivity of Swarna and Swarna Sub1 might be due to low fluorescent intensity at ‘J’ and ‘I’ transient point as compared to check variety. Total performance index on absorption basis was fund significantly high in Swarna and Swarna Sub1 as compared to TDK and TDK Sub1 with higher yield performance. Cluster analysis confirmed close relation of Bahadur and Bahadur Sub1 as well as Swarna and Swarna Sub1. TDK and TDK Sub1 found distantly related as evident by PCA analysis which confirmed a high amount of genetic alteration due to Sub1 introgression in this variety with high grain number and high plot yield. The identified genetically distinct genotype TDK and TDK Sub1 could be selected for breeding partner with high photosynthetic activity, high grain weight with more grain number per panicle following conventional rice breeding program.