Among the Brassica oilseeds, canola (Brassica napus) is the most economically significant globally. However, its production can be limited by blackleg disease, caused by the fungal pathogen Lepstosphaeria maculans. The deployment of resistance genes has been implemented as one of the key strategies to manage the disease. Genetic resistance against blackleg comes in two forms: qualitative resistance, controlled by a single, major resistance gene (R gene), and quantitative resistance (QR), controlled by numerous, small effect loci. R-gene-mediated blackleg resistance has been extensively studied, wherein several genomic regions harbouring R genes against L. maculans have been identified and three of these genes were cloned. These studies advance our understanding of the mechanism of R gene and pathogen avirulence (Avr) gene interaction. Notably, these studies revealed a more complex interaction than originally thought. Advances in genomics help unravel these complexities, providing insights into the genes and genetic factors towards improving blackleg resistance. Here, we aim to discuss the existing R-gene-mediated resistance, make a summary of candidate R genes against the disease, and emphasise the role of players involved in the pathogenicity and resistance. The comprehensive result will allow breeders to improve resistance to L. maculans, thereby increasing yield.

Heat stress affects the growth and development of Brassicaceae crops. Plant breeders aim to mitigate the effects of heat stress by selecting for heat stress tolerance, but the genes responsible for heat stress in Brassicaceae remain largely unknown. During heat stress, heat shock proteins (HSPs) function as molecular chaperones to aid in protein folding, and heat shock transcription factors (HSFs) serve as transcriptional regulators of HSP expression. We identified 5002 heat shock related genes, including HSPs and HSFs, across 32 genomes in Brassicaceae. Among these, 3347 genes were duplicated, with segmented duplication primarily contributing to their expansion. We identified 466 physical gene clusters, including 240 homogenous clusters and 226 heterogeneous clusters, shedding light on the organization of heat shock related genes. Notably, 37 genes were co-located with published thermotolerance quantitative trait loci, which supports their functional role in conferring heat stress tolerance. This study provides a comprehensive resource for the identification of functional Brassicaceae heat shock related genes, elucidates their clustering and duplication patterns and establishes the genomic foundation for future heat tolerance research. We hypothesise that genetic variants in HSP and HSF genes in certain species have potential for improving heat stress tolerance in Brassicaceae crops.

Various diseases severely affect Brassica crops, leading to significant global yield losses and a reduction in crop quality. In this study, we used the complete protein sequences of 49 cloned resistance genes (R genes) that confer resistance to fungal and bacterial diseases known to impact species in the Brassicaceae family. Homology searches were carried out across Brassica napus, B. rapa, B. oleracea, B. nigra, B. juncea, B. carinata and Arabidopsis thaliana genomes. In total, 660 cloned disease R gene homologs (CDRHs) were identified across the seven species, including 431 resistance gene analogs (RGAs) (248 nucleotide binding site-leucine rich repeats (NLRs), 150 receptor-like protein kinases (RLKs) and 33 receptor-like proteins (RLPs)) and 229 non-RGAs. Based on the position and distribution of specific homologs in each of the species, we observed a total of 87 CDRH clusters composed of 36 NLR, 16 RLK and 3 RLP homogeneous clusters and 32 heterogeneous clusters. The CDRHs detected consistently across the seven species are candidates that can be investigated for broad-spectrum resistance, potentially providing resistance to multiple pathogens. The R genes identified in this study provide a novel resource for the future functional analysis and gene cloning of Brassicaceae R genes towards crop improvement.

The study of genetic variation (GV) in 20 Philippine traditional rice varieties (TRVs) were determined in grain morphology such as length (Gl), width (Gwd), and weight (Gwt), grain yield (Gy), and grain micronutrients such as copper (Cu), iron (Fe), manganese (Mn) and zinc (Zn). Analysis of variance obtained highly significant GV among TRVs in all traits. The mean for Gl, Gwd, Gwt, Gy, Cu, Fe, Mn, and Zn contents was 8.56mm, 2.8mm, 20.01g, 2.13t/ha, 8.64ppm, 14.56ppm, 20.79ppm, and 30.26ppm, respectively. The micronutrients in TRVs followed an order as Zn > Mn > Fe > Cu. For the correlation in traits, 11 pairs were significantly correlated; however, only Mn and Zn content in grains was positively and strongly correlated. Other significant pairs were either in positive or negative and moderately correlated. Cluster analysis, on the other hand, revealed five clusters and showed distinct TRV in two clusters. In conclusion, the presence of higher grain micronutrient content in TRVs indicatesa better opportunity for breeders to determine parental genetic resource in breeding rice with high grain micronutrients. Bangladesh J. Sci. Ind. Res.55(1), 35-42, 2020

Brassicaceae crops, including Brassica, Camelina and Raphanus species, are among the most economically important crops globally; however, their production is affected by several diseases. To predict cloned disease resistance (R) gene homologs (CDRHs), we used the protein sequences of 49 cloned R genes against fungal and bacterial diseases in Brassicaceae species. In this study, using 20 Brassicaceae genomes (17 wild and 3 domesticated species), 3172 resistance gene analogs (RGAs) (2062 nucleotide binding-site leucine-rich repeats (NLRs), 497 receptor-like protein kinases (RLKs) and 613 receptor-like proteins (RLPs)) were identified. CDRH clusters were also observed in Arabis alpina, Camelina sativa and Cardamine hirsuta with assigned chromosomes, consisting of 62 homogeneous (38 NLR, 17 RLK and 7 RLP clusters) and 10 heterogeneous RGA clusters. This study highlights the prevalence of CDRHs in the wild relatives of the Brassicaceae family, which may lay the foundation for rapid identification of functional genes and genomics-assisted breeding to develop improved disease-resistant Brassicaceae crop cultivars.

Traditionally, rice cultivation has heavily relied on single varieties tailored for specific traits, yet these approaches have demonstrated limitations in resilience and stability. Embracing variety mixtures (VarMix) allows us to leverage genetic diversity, thereby enhancing yield stability, bolstering pest and disease management, and optimizing resource efficiency, ultimately fostering more sustainable and resilient rice production systems. This study investigates the performance of 12 rice varietal mixtures and single varieties across 12 distinct environments using the Additive Main Effects and Multiplicative Interaction (AMMI) approach, integrating variance and principal component analyses (PCA). The analysis reveals environmental factors as the predominant driver of genetic variation, with significant contributions to rice yield dynamics. Notably, genotypes such as NSIC Rc298 (A), NSIC Rc298: NSIC Rc214: NSIC Rc216 (ABC), and NSIC Rc214: PSB Rc82: NSIC Rc238 (BDE) consistently exhibited high yield across multiple environments. Furthermore, varietal mixtures, particularly BDE, demonstrated both high yield and stability, highlighting the potential of mixed genotypes in enhancing agricultural resilience. The findings underscore the importance of tailored breeding strategies and environmental considerations in maximizing rice yield and stability, contributing to sustainable crop production practices and food security initiatives.