Abstract:
The emasculation of male gametes in pollen-recipient parents among self-pollinated crops (rice) is key
to producing quality hybrid rice seeds. One of the emasculation tools in rice breeding is the photoperiodthermo sensitive genic male sterility (P/TGMS) method, which ultimately requires long daylight length
and high-temperature growth conditions to induce male gametes sterility. Using the P/TGMS method to
produce hybrid Basmati rice seeds has been slow because no commercial line has been developed.
Crossing the Basmati rice line with a non-aromatic rice line produces F1 with non-basmati quality traits.
This study aimed to introgress the p/tgms12-1 gene into Basmati 370 by treating P/TGMS lines (IR7327-2376-157S and IR-75589-31-27833S) with daytime temperatures (>33ºC) under a polythene
greenhouse to emasculate pollen and cross-pollinating them with Basmati 370. Marker-assisted
backcrossing was used to develop the BC1F2 Basmati breeding lines evaluated for pollen sterility and
agro-morphological traits. Pollen sterility was tested by staining with 1% iodine potassium-iodide
solution (I2KI), in which fertile and sterile pollen grains were stained with blue-black and yellow-pink
dyes, respectively. The acquisition of near-complete pollen sterility among female parents is a
manifestation of the greenhouse temperatures effectively emasculating pollen in P/TGMS parents and
BC1F2. Analysis of variance on agro-morphological data showed significantly better agro-morphological
traits in BC1F2 than the parents and significantly higher pollen sterility in P/TGMS lines than Basmati
370 (P≤0.05). The presence of the fgr gene in BC1F2 lines was confirmed using SSR markers, and the
hybrids had both homozygous aromatic and heterozygous non-aromatic traits, the successful
development of BC1F2 with p/tgms12-1 and fgr genes. The results obtained from this study are a major
milestone towards improving Basmati rice yields in Kenya using hybrid seeds
