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While it is crucial for developing countries like Malaysia to achieve self-sufficiency in rice (Oryza sativa L.), it is equally critical to be able to produce high-quality rice, specifically fragrant rice, which demands are often met through importation. The present study was aimed at developing high-yielding fragrant rice, in a timely and cost-effective manner. A marker-assisted backcross (MABC) approach was optimised to introgress the fragrance gene (fgr) into two high-yielding Malaysian varieties, MR84 and MR219, within two years utilising less than 50 molecular markers. Coupled with phenotypic screening, one single foreground marker (fgr-SNP) and 48 background markers were selected and utilised, revealing recovery of at least 90% of recurrent parent genome (RPG) in merely two backcross generations. Collectively, the yield potential of the developed B[C.sub.2][F.sub.2] lines (BLs) was higher (P > 0.05) than the donor parent, MRQ74, and similar (P < 0.05) to both the recurrent parents, MR84 and MR219. In addition, some of the developed BLs showed good grain quality, such as having long grain. We believe that this is the first report comprising the validation and utilisation of the single functional marker system (fgr-SNP) in introgressing the fgr gene into different rice varieties. Key words: fgr gene, fragrant, marker-assisted backcrossing, recurrent parent genome, rice. Résumé : Bien qu'il soit crucial pour des pays en développement comme la Malaisie de devenir auto-suffisants en matière de production de riz (Oryza sativa L.), il est également important qu'ils soient en mesure de produire du riz de haute qualité, spécifiquement du riz parfumé, dont la demande est souvent rencontrée par le biais de l'importation. La présente étude visait à développer un riz parfumé à haut rendement de manière rapide et efficace. Une approche de rétrocroisement assistée de marqueurs (MABC) a été optimisée afin d'introduire le gène de fragrance (fgr) au sein de deux variétés malaisiennes à haut rendement (MR84 et MR219) en moins de deux ans et avec moins de 50 marqueurs moléculaires. Conjointement à une sélection phénotypique, un marqueur associé au caractère (fgr-SNP) et 48 marqueurs pour le fonds génétique ont été choisis et utilisés. Ces marqueurs ont permis de constater qu'au moins 90% du bagage génétique provenait du parent récurrent au terme de seulement deux rétrocroisements. Collectivement, le rendement potentiel des lignées B[C.sub.2][F.sub.2] (BL) était supérieur (P > 0,05) à celui du parent donneur (MRQ74) et semblable (P < 0,05) à celui des parents récurrents (MR84 et MR219). De plus, certaines des lignées ainsi développées présentaient une bonne qualité, tel que des grains longs. Les auteurs estiment qu'il s'agit du premier travail rapportant la validation et l'emploi d'un unique marqueur fonctionnel (fgr-SNP) pour l'introgression du gène fgr au sein de variétés de riz. [Traduit par la Rédaction] Mots-clés : gène fgr, parfumé, rétrocroisement assisté de marqueurs, génome du parent récurrent, riz., Introduction In a world of rising population and booming economy, there is a great importance in developing sufficient key food staples with desirable qualities, and such is the case of [...]

Heat and drought stress, which often co-occur due to water evaporation, are two major abiotic factors limiting the production of rice (Oryza sativa L.) It is crucial to enhance understanding of the effects of these abiotic stresses in rice, particularly for rice-producing countries like Malaysia, which has yet to achieve rice selfsufficiency. This greenhouse study was conducted to evaluate the morphological changes of two important Malaysian cultivars (‘MR219’ and ‘MR303’) at vegetative, reproductive, and ripening stages, as well as their physiological response and yield components under normal (control), heat, drought, and combined heatdrought stress conditions. Individual heat stress greatly influenced rice growth and yield, with significant differences (p < 0.01) observed across all examined parameters except the grain to leaf area index ratio (GtoLAI). Conversely, individual drought stress mostly affected yield-related parameters, with significant differences (p < 0.01) in grain weight (GW), harvest index (HI), and percentage of filled grain (%FG). Interestingly, the combined stresses in this study did not significantly affect plant height (PH) for all growth stages and most yield-related traits (HI, GW, and GtoLAI). The majority of the significant changes (p < 0.01) were observed on physiological traits, including chlorophyll a (Chl A) and b (Chl B). We found a positive correlation between HI and %FG (R² = 0.3974**) under heat and drought stress, indicating that improving either of these traits can boost rice production. Collectively, our study revealed that the individual effects of heat and drought on rice growth and yield can differ from the effects of combined stress. [ABSTRACT FROM AUTHOR]

Rice, the first crop to be fully sequenced and annotated in the mid-2000s, is an excellent model species for crop research due mainly to its relatively small genome and rich genetic diversity. The 130-million-year-old cereal came into the limelight in the 1960s when the semi-dwarfing gene sd-1 , better known as the "green revolution" gene, resulted in the establishment of a high-yielding semi-dwarf variety IR8. Deemed as the miracle rice, IR8 saved millions of lives and revolutionized irrigated rice farming particularly in the tropics. The technology, however, spurred some unintended negative consequences, especially in prompting ubiquitous monoculture systems that increase agricultural vulnerability to extreme weather events and climate variability. One feasible way to incorporate resilience in modern rice varieties with narrow genetic backgrounds is by introgressing alleles from the germplasm of its weedy and wild relatives, or perhaps from the suitable underutilized species that harbor novel genes responsive to various biotic and abiotic stresses. This review reminisces the fascinating half-century journey of rice research and highlights the potential utilization of weedy rice and underutilized grains in modern breeding programs. Other possible alternatives to improve the sustainability of crop production systems in a changing climate are also discussed., Competing Interests: The authors declare no conflicts of interest.