Date Received: 06-02-2025 / Date Published: 20-02-2025
The pot experiment was conducted in the nethouse of the Faculty of Agronomy - Vietnam National University of Agriculture in 2022 autumn cropping seasons to evaluate the photosynthetic traits at active tillering, flowering and dough-ripen stage and grain yield at harvesting stages of four rice lines with wealthy farmer's panicle (WFP1 gene). The experimental results showed that these improved rice lines had photosynthetic rates and related characteristics such as stomatal conductance, transpiration rate and SPAD value equivalent to the control variety (IRBB) at almost the growth stages. These four lines showed a similar amount of dry matter accumulation and plant growth rate in the period from effective tillering to heading, but these parameters were surpassed the check variety in D7 line in the period from flowering to the dough-ripening stage. All improved rice lines had a significantly larger number of primary rachis per panicle (17.1-20.1), number of secondary rachis per panicle (65.7-73.2) and number of spikelets per panicle (177.6-226.4) compared with IRBB. The individual yield of three improved lines (D2, D5 and D7) was significantly higher in the range of 13.6-32.0% over than check variety. Among new lines, D7 line manifested the highest grain yield due to the largest number of spikelets per panicle, higher photosynthetic rate at the flowering stage and plant growth rate in period from flowering to the dough-ripening stage.
