Moruga Hill Rice (MHR) is an African rice (Oryza glaberrima Steud.) brought to Trinidad by formerly enslaved African Americans and has been grown for many generations in Trinidad at subsistence and commercial scale. Despite its historical and agricultural significance, genomic resources specific to MHR remain unexplored, and its genetic composition, evolutionary history, and potential agronomic traits have not been characterized. This current study presents the first draft genome assembly of the MHR genome using a hybrid sequencing approach. The MHR genome size was found to be ~372.9 Mb with 56,073 predicted genes. Variant analysis revealed a total of 3,318,242 variants, of which 2,440,476 were SNPs, and 877,766 were InDels. Several candidate genes encoding proteins with orthology to previously characterized biotic resistance and abiotic stress-responsive genes in rice were identified. Potential gene families identified prompt further investigation of their roles in MHR drought and salt stress responses. Phylogenomic analysis of O. glaberrima landraces suggests that MHR shares close genetic affinity with the IRGC−104595 Malian landrace, consistent with historical records. This assembly thus expands the African rice genomic repository, providing a foundation to understand the genetic architecture underlying key phenotypic traits and identifying potential novel gene sources in MHR for rice improvement in the Caribbean region.
Uddesh M. Sahadeo, Omar Ali, A. Ramsubhag et al.· BioTech· 0 citations
Several environmental and economic issues have been brought about by mass accumulations of Sargassum seaweed along the coastlines in Trinidad and Tobago, and the wider Caribbean region. Though there are many issues associated with this seaweed biomass, there remains opportunities to transform this problem into a solution. The current study presents the evaluation of a Sargassum biostimulant formulation (OJA1) and its effect on tomato. Tomato plants were foliar (0.5% v/v) treated with the OJA1 biostimulant under both greenhouse and field conditions. OJA1 significantly improved plant performance (p < 0.05) by means of increased chlorophyll (22.7%), plant height (29.3%), root biomass (34.4%), shoot biomass (49.6%), and yield (54.8%), while reducing disease severity by 37.8% for bacterial spot and 37.5% for early blight under greenhouse conditions. In field trials, OJA1 significantly increased yield and reduced disease severity across both growing seasons. Yield increases ranged from 75.6–103.2% with OJA1 alone and 114.6–154.8% when alternated with fungicides. Similarly, bacterial leaf spot and early blight severity were reduced by up to 50.6% and 61.8%, respectively, relative to the Control. Molecular mechanistic testing revealed that OJA1-treated tomato plants had more than a two-fold increase in gene transcripts responsible for abiotic/biotic stress tolerance and biosynthesis of growth hormones. Additionally, OJA1-treated plants had significantly lower DNA levels of both pathogens. Additional analysis further showed that OJA1-treated plants had significantly higher hormonal content (auxin, cytokinin, and gibberellin), and fruits had significantly higher mineral content (N, P, K, Na, and Zn) than Control plants. The results exemplify the valorisation potential of Sargassum and could contribute to sustainable agriculture and propels economic development in coastal communities.
Omar Ali, M. Arsene, A. Ramsubhag et al.· Discover Plants· 0 citations