Introduction: Modern sugarcane cultivars originate from a limited genetic pool, primarily comprising Saccharum spontaneum and S. officinarum , which restricts yield improvements and stress resilience. It's vital to conserve and utilize genetic diversity from the World Collection of Sugarcane and Related Grasses (WCSRG) and is a key resource for future advancements. Methods: The Cane Presentation System measures essential parameters, including Brix, Polarity, moisture, and fiber content, which are critical for evaluating sugar extraction potential and processing efficiency. Molecular markers hold significant value in sugarcane breeding, and genome-wide association studies have been conducted to identify genetic loci associated with these target traits. Results: The study assessed variations in cane quality traits (Brix, polarity, fiber, and moisture content), finding that hybrids and S. robustum outperformed in these characters. Trait correlation analysis indicated independent genetic control, forming a basis for future research. Genome-wide association studies identified 40 significant SNPs across chromosomes 2 to 8, with markers on chromosomes 4, 6, and 7 consistently associated with Brix, and markers on chromosomes 2 and 5 linked to fiber. Additionally, marker AX-171243917-4651 on chromosome 6D was associated with both Brix and polarity. Discussion: This study examines the genetic diversity and trait associations in sugarcane, emphasizing the application of stable SNP markers linked to key characteristics, such as Brix, Polarity, and fiber content, for enhancing multiple traits through marker-assisted selection. The findings reveal significant phenotypic variation among Saccharum species, advocating for a broad genetic base in breeding programs. Due to sugarcane's polyploid nature, the study calls for further validation through fine mapping, gene expression analysis, and multi-location testing. Future research should enhance marker density, expand populations, and adopt new genomic approaches for effective crop improvement.

The Thielaviopsis paradoxa species complex comprises fungal pathogens that cause both bud (heart) and trunk rot of palms. Thielaviopsis spp. are soilborne pathogens that infect all plant parts (i.e., roots, stem, leaves, and fruits) of primarily monocot hosts, including palms, banana, sugarcane, and pineapple. However, very little is known about the T. paradoxa species complex in the United States and the palm-Thielaviopsis pathosystem. Our previous analysis showed that the T. paradoxa complex comprises at least two species in Florida, T. ethacetica and a novel, undescribed Thielaviopsis species. To study the interaction, a detached leaflet assay for palms was established to test the pathogenicity of the species in the T. paradoxa complex. Lesion size was measured quantitatively and used to assess pathogenicity of the fungal isolates and host response. Wounding the detached leaflets promoted lesion development, and disease symptoms were similar to whole plants. A comparison of the two Thielaviopsis species showed that all T. ethacetica isolates consistently produced larger lesions and were more aggressive than the undescribed Thielaviopsis species in detached leaflet assay on foxtail palms (Wodyetia bifurcata). Subsequently, T. ethacetica was used to screen 262 individuals from 29 species across 17 genera of palms using the detached leaflet assay. Lesion development in individuals from at least five palm species across four genera was significantly different from the negative control, suggesting that these palm species may be susceptible to T. ethacetica. Additionally, variation in lesion development was also observed at varietal level in coconut palms. This detached leaflet assay would facilitate dissection of the Thielaviopsis-palm interaction and accelerate screening of palm germplasm repositories to identify sources of resistance to Thielaviopsis.

Avocado is a slow-maturing fruit crop, requiring costly management of tree architecture and canopy throughout the production season. Improving tree architecture can significantly lower avocado grove management costs, and genetic studies can play a key role in this. We analyzed two large F ₁ segregating populations derived from reciprocal crosses between important avocado cultivars: ‘Simmonds’ (West Indian) and ‘Tonnage’ (Guatemalan). These populations were assessed for various tree architectural traits including plant height, trunk diameter and canopy size and volume. Genotyping was performed using single nucleotide polymorphism (SNP) markers from a 6 K Illumina SNP chip. Quantitative trait locus (QTL) analysis via GWAS models identified distinct genetic loci associated with the traits of interest. Notably, two QTLs for tree architecture traits were consistently observed on chromosomes 2 and 11, which offer preliminary insights into the genetic basis of these traits in avocado. These findings provide preliminary markers for future validation and potential use in molecular breeding to support avocado improvement efforts.

Ug99 is a highly destructive race of stem rust fungus known as Puccinia graminis Pers. f. sp. tritici Eriks. & E. Henn. (Pgt). To address this problem, the International Maize and Wheat Improvement Center, Mexico (CIMMYT) has extensively employed adult plant resistance (APR), which combines multiple genes that provide slow rusting resistance. CIMMYT’s advanced germplasm, “Diniza,” has proven to possess a good level of APR for the Ug99 race group. This study identified the genomic regions responsible for providing APR in the PBW343/Diniza RIL population. Study identified four quantitative trait loci (QTLs) that provide slow rusting APR on chromosomes 2B (QSr.cimm-2B), 3BS (QSr.cimm-3BP1 and QSr.cimm-3BP2), and 7DS (QSr.cimm-7D). These QTLs explained phenotypic variances of 17.0, 18, 8.9, and 11.6%, respectively. Three QTLs, QSr.cimm-2B, QSr.cimm-3BP2, and QSr.cimm-7D, were derived from APR parent ‘Diniza’, while QSr.cimm-3BP1 was derived from ‘PBW343’. Further, QTL class analysis revealed the additive and epistatic interaction results of the identified QTL(s), suggesting that combinations of several QTLs can effectively reduce disease severity. Unlike, QSr.cimm-2B, QTLs QSr.cimm-3BP1 and QSr.cimm-7D co-localized with the previously identified stem rust resistance genes. The identified QTL can be combined to enhance stem rust resistance in breeding materials.

Impact of the green revolution genes on rice and wheat productivity under rainfed environments has been debated since past few decades. Here we made an attempt to assess the impact of two major green revolution genes Rht B1 and Rht D1 on grain yield under drought stress. A total of four recombinant inbred line (RIL) populations were analyzed for this objective including PBW343 × Muu, PBW343 × Kingbird, PBW343 × Kenyaswara and Jal 95.4.3 × Kachu/Kiritati/Kachu. These populations segregated for either or both the Rht gene alleles. Our results revealed an invariable non-association of tall/ dwarf alleles of Rht B1 and Rht D1 genes with grain yield under drought stress. Tightly linked sequence tags with Rht and Vrn genes were identified for future application in wheat breeding. A genetic linkage map of 1170 DArt-seq markers covering 2870 cM was constructed in Jal 95.4.3 × Ka-chu/Kiritati/Kachu RIL population and QTLs for yield related traits were identified. Study provides an insight for researchers involved in developing the next generation climate resilient wheat varieties that can cope well with rainfed/ drought prone en-vironments.