Biology subjects

Clarindo, W. R.

Publications and source records attributed to Clarindo, W. R..

4 recordsLinked to original sources

bioRxiv2025

A draft genome assembly of the agricultural pest Leucoptera coffeella and analysis of its dsRNA processing machinery is a key step towards RNAi-based biopesticides in Lepidoptera

The Coffee Leaf Miner (Lepidoptera: Lyonetiidae: Leucoptera coffeella) is a specialist herbivore and major global pest of coffee plants. Current pest control strategies primarily rely on chemical pesticides, leading to human and environmental constraints. Additionally, the emergence of insecticide-resistant populations underscores the urgent need for more specific and efficient pest management strategies. The development of novel techniques for controlling this insect pest requires rigorous interrogation of its physiology and interactions with host plants at a molecular/genetic level. To enable future research in this vein, we sequenced and assembled a draft L. coffeella genome using PacBio highly accurate long-reads (HiFi). Our assembly is comprised of 1615 contigs showing fragmentation, yet the majority of gene content is represented (BUSCO complete = 91.7%). We annotated 17467 protein-coding genes within our assembly, seven of which are core components of the small interfering RNA machinery. The expression of these genes was further confirmed via qPCR. This analysis - and the underlying genomic data - highlights potential targets for RNAi-based biopesticide development and will serve as the foundation for important future research aimed at protecting global coffee production from one of its most destructive pests.

genomics↗

bioRxiv2023

Popcorn haploids identified by Navajo phenotype and ploidy level

For popcorn, obtaining and identifying haploids are still challenging steps. We aimed to induce and screen haploids in popcorn using the Navajo phenotype, seedling vigor and ploidy level. We used the Krasnodar Haploid Inducer (KHI) in crosses with 20 popcorn source germplasms and five maize controls. The field trial design was completely randomized, with three replications. We assessed the efficacy of induction and of identification of haploids based on haploidy induction rate (HIR) and false positive and negative rates (FPR and FNR). Additionally, we also measured the penetrance of the Navajo marker gene (R1-nj). All putative haploids classified by R1-nj were germinated together with a diploid sample and evaluated for false positives and negatives based on vigor. Seedlings from 14 females were submitted to flow cytometry to determine the ploidy level. The HIR and penetrance were analyzed by fitting a generalized linear model with a logit link function. The HIR of the KHI, adjusted by cytometry, ranged from 0.0 to 1.2%, with a mean of 0.34%. The average FPR from screening based on the Navajo phenotype were 26.2% and 76.4%, by the vigor and ploidy, respectively. The FNR was zero. The penetrance of R1-nj ranged from 30.8 to 98.6%. The average number of seeds per ear in temperate germplasm (76) was lower than that obtained in tropical germplasm (98). There is induction of haploids in germplasm of tropical and temperate origin. We recommend the selection of haploids associating the Navajo phenotype with a direct method of confirming the ploidy level, such as flow cytometry. We also show that haploid screening based on Navajo phenotype and seedling vigor reduces misclassification. The origin and genetic background of the source germplasm influence the R1-nj penetrance. Because the known inducers are maize, developing doubled-haploid technology for popcorn hybrid breeding requires overcoming the unilateral cross-incompatibility.

genetics↗

bioRxiv2021

A heterochromatic knob reducing the flowering time in maize

Maize flowering time is an important agronomic trait, which has been associated with variations in the genome size and heterochromatic knobs content. We integrated three steps to show this association. Firstly, we selected inbred lines varying for heterochromatic knob composition at specific sites in the homozygous state. Then, we produced homozygous and heterozygous hybrids for knobs. Second, we measured the genome size and flowering time for all materials. Knob composition did not affect the genome size and flowering time. Finally, we developed an association study and identified a knob marker on chromosome 9 showing the strongest association with flowering time. Indeed, modelling allele substitution and dominance effects could offer only one heterochromatic knob locus that could affect flowering time, making it earlier rather than the knob composition.

genetics↗

bioRxiv2021

Photoperiod shapes aluminium tolerance in plants

Aluminium is a limiting factor for crop productivity in acidic soils (pH [≤] 5.5). Since acid soil distribution on Earth cannot adequately explain the differential Al tolerance across the plant kingdom, we investigated photoperiod effects on plant Al tolerance. We observed that with increasing distance from the equator, Al tolerance disappears, suggesting a relationship with the photoperiod. Long-day (LD) species are generally more Al-sensitive than short-day (SD) species, whereas genetic conversion of tomato for SD growth boosts Al tolerance. Reduced Al tolerance correlates with DNA-checkpoint activation under LD. DNA-checkpoint-related genes are under positive selection in Arabidopsis accessions from regions with shorter days, suggesting photoperiod acts as a selective barrier for Al tolerance. Our findings revealed that diel regulation and genetic diversity affect Al tolerance, suggesting that day-length orchestrates Al tolerance. One-Sentence SummaryAluminum is a major constraint for crop yield worldwide. We reveal that photoperiod acts as a barrier for Al tolerance in plants.

plant biology↗