FEASIBILITY OF BASMATI HYBRID SEED PRODUCTI ON IN KENYA USING HIGH-TEMPERATURE–INDUCED EGMS (2-LINE SYSTEM)

Abstract

The need to increase rice yield has prompted breeders to adopt hybrid rice seed technology. The main challenge has been finding a female parent that is completely male-sterile so it can be pollinated by a pollen donor. Basmati rice lines are difficult to cross with other lines, limiting the use of their hybrids for yield improvement. The objective of this study was to cross Environment-Sensitive Genic Male Sterile (EGMS) with Basmati to produce hybrid Basmati rice seeds to improve rice yield in Kenya. Photoperiod-sensitive genic male-sterile rice lines IR-73827-23-76-15-7 S and IR-75589-31-27-8-33-2S, and a thermosensitive genic male-sterile line, IR77271-42-25-4-36S, known as P1, P2 and T1, respectively, were obtained from the International Rice Research Institute. These lines were grown under greenhouse (GH) conditions, where temperatures exceeded 34°C to induce complete male sterility. Results showed that under high GH temperatures, both PGMS and TGMS lines had over 89.2±1.8ef pollen sterility, which positively corresponded with over 98.9±0.3d spikelet sterility, whereas Basmati (370 and 217) had as low as 85.8±2e pollen sterility and 69.5±1.1c spikelet sterility, particularly for Basmati217. The best hybrid seed yield was from the cross between Basmati217 and T1(V3), with an average of 39.12%, compared to the control lines (unpollinated), which had 0% seed production, indicating the potential for local Basmati seed production. When tested under GH growth conditions, hybrid lines P1B217 and P2B217 had the highest filled spikelet of 68.5±1.2e and 69.5±1.4e, compared to Basmati370 and 217, which had 37.1±1.4b and 34.3±1.3b, and EGMS P1 and T, which had filled spikelets of 0.7±0.3a and 1.7±0.4a, respectively. This indicates the feasibility of increasing Basmati yield in Kenya using hybrid seed technology (EGMS method) with hybrid seeds free of contamination from self-bred seeds. Additionally, Basmati370 appears to exhibit better heterosis than Basmati217 for most strains studied. In conclusion, the EGMS method should be enhanced to produce Basmati hybrid rice seeds to increase yield and food security.