Robusta (Coffea arabica L.) and Arabica (Coffea canephora A. Froehner) are the major agricultural commodities in Central Sulawesi, Indonesia, known for their unique flavor mostly influenced by local microclimates. The following study aimed to analyze the genetic diversity of 12 coffee genotypes procured from the Central Sulawesi Region using RAPD markers. Ten RAPD primers (OPA01, OPA02, OPA07, OPA16, OPD08, OPA13, OPG03, OPI07, OPY10, and OPX20) generated 103 DNA bands, with 102 as polymorphic. The DNA profiles’ binary data underwent analysis using Jaccard similarity coefficients and the unweighted pair group method with arithmetic mean (UPGMA) clustering. Genetic similarity ranged from 7% to 72%, with an average of 31%. Cluster analysis grouped the coffee genotypes into two main clusters unrelated to their taxonomic classifications, implying extensive genetic divergence potentially driven by local environmental conditions. Four non-conventional primers (OPA02, OPA13, OPA16, and OPD08) successfully amplified the DNA in several local genotypes. However, the local genotype Robusta Dombu did not amplify with any primer, pointing to possible mutation, highlighting its distinct genetic makeup. The results demonstrated a significant genetic diversity among the local coffee genotypes. Robusta Dombu, being a local coffee genotype, emerges as a potential candidate for developing climate-resilient and high-quality cultivars.

Keywords: Arabica, biodiversity, Coffea arabica, Coffea canephora, local adaptation, RAPD, Robusta

Key findings: The study showed the high genetic diversity in Coffea spp. genotypes by using RAPD markers. The phylogenetic clusters have not shown their belonging to two main ancestors, Robusta and Arabica, suggesting their highest variability during adaptation to local conditions.

This latest study aimed to evaluate the triticale cultivars for drought tolerance through morphophysiological traits and molecular analyses. Under artificial drought conditions induced by the polyethylene glycol (PEG-6000), the triticale cultivars Sergiy, Xlebarob, and K. Prag exhibited the highest tolerance and demonstrated better adaptability to drought stress conditions. Molecular analysis identified the alleles (Xgwm484, Xmc525, and Xgwmc389) associated with drought tolerance based on DNA markers, establishing these markers as reliable indicators for selection. Specifically, alleles with 255 bp (Xgwm484), 230 bp (Xmc525), and 260 bp (Xgwmc389) were indicative of drought tolerance, confirming the highest drought tolerance in the cultivars K. Prag, Sergiy, and Xlebarob. These cultivars showed potential for future breeding using molecular techniques like gene pyramiding to enhance drought resistance and are suitable as elite initial material for the selection process. The phylogenetic analysis revealed genetic similarities and differences among the triticale cultivars, highlighting the crucial role of drought tolerance-related markers in selection and ensuring sustainable productivity. The results provided fundamental insights for determining the drought tolerance levels among triticale cultivars and defining future selection directions.

Keywords: Triticale cultivars, drought stress tolerance, PEG-6000, morphophysiological traits, DNA markers, phylogenetic analysis, productivity

Key findings: The study identified drought-tolerant alleles in triticale cultivars using markers Xgwm484, Xmc525, and Xgwmc389. The allele Xgwm484 with 255 bp appeared in cultivars Sardor, K. Prag, Sergiy, and Xlebarob, while the allele Xmc525 with 230 bp was evident in triticale cultivars Tixon, Kunak, Yarillo, K. Prag, Sergiy, Xlebarob, and Prao-02, confirming their highest drought tolerance.

The estimation of genetic parameters of the kenaf (Hibiscus cannabinus L.) plant resistance against root-knot nematodes (M. incognita) using full diallel cross analysis was the aim of this study. Seven H. cannabinus parental genotypes, KR-1, KR-4, KR-5, KR-6, KR-15, Kenafindo-2 (Kin-2), and DS-028, as well as their complete diallel F₁ hybrids, were samples used in the study. The experiment commenced by infecting kenaf plants aged 15 days after sowing (DAS) with M. incognita nematodes in a population of 40 second-stage juveniles/100 g soil. The resistance variables comprised the number of root-knot nematodes, reproductive factors, the number of second-stage juveniles, the total egg mass, and the average number of eggs per mass. The results showed no significant epistatic interaction between genes in determining H. cannabinus resistance against M. incognita. Moreover, the effect of the additive genetic variances was greater than the dominance genetic variances. The kenaf resistance against root-knot nematode revealed the primary control of a partially dominant-additive gene. Dominant genes proved more prevalent than recessive genes in the parental genotypes. Both broad- and narrow-sense heritability values emerged as high.

Keywords: Kenaf (H. cannabinus L.), root-knot nematodes (M. incognita), Hayman’s diallel analysis, genetic parameters, additive and dominance genetic variances, heritability

Key findings: The kenaf (H. cannabinus L.) resistance against root-knot nematode showed the control of a partially dominant gene. Dominant genes appeared more abundant than recessive ones in the parental genotypes. Both broad- and narrow-sense heritability values were high.

Pepper (Capsicum annuum L.) is a vital food commodity, and its shelf life plays a crucial role in determining economic viability. Ethylene, a key regulator in the ripening of climacteric fruits, such as peppers, considerably affects postharvest longevity. The ethylene biosynthesis pathway incurs management from gene families encoding 1-aminocyclopropane-1-carboxylate synthase (ACS) and 1-aminocyclopropane-1-carboxylate oxidase (ACO). The following study investigated the expression patterns of the ACS gene (CaACS6) and the ACO gene (CaACO1), along with a housekeeping gene (CaGAPDH), in three pepper cultivars (Cherry, Anaheim, and Bohemian), using quantitative polymerase chain reaction (qPCR). Gene expression assessment progressed across three maturity developmental stages (young green, large green, and ripening) to elucidate their influence on ethylene synthesis and pepper shelf life. The expression of the CaACS6 gene showed a positive correlation with the ripening stage across all cultivars. In the Cherry cultivar, the expression of gene CaACO1 significantly decreased at the ripening stage, indicating reduced ethylene production and potential for extended shelf life. Similarly, the Anaheim cultivar exhibited a decrease in the expression of both genes (CaACS6 and CaACO1) during the ripening stage, revealing a reduced ethylene production, suggesting a potential for reduced ethylene production and extended shelf life. These insights provide valuable guidance for selecting pepper cultivars with prolonged shelf life, thereby enhancing postharvest quality and commercial sustainability.

Keywords: Pepper (C. annuum L.), cultivars, CaACS6 and CaACO1, gene expression, ethylene production regulatory genes, maturity stages

Key findings: In pepper (C. annuum L.) cultivars, the gene CaACS6 expression with an increased ethylene biosynthesis at the ripening stage, confirmed its role in maturation. Reduced gene CaACO1 expression in pepper cultivars (Cherry and Anaheim) at the ripening stage suggested lower ethylene production, supporting their potential for extended shelf life.

Kasturi tobacco (Nicotiana tabacum L.) is a sun-cured aromatic cultivar prized for its unique flavor and economic potential in premium blends. However, in Indonesia its cultivation constraints come from genetic degradation and susceptibility to various diseases, such as Phytophthora nicotianae, Ralstonia solanacearum, and Cucumber Mosaic Virus (CMV). This study sought to develop high-yielding, disease-resistant, and quality-consistent Kasturi genotypes through the integration of cytoplasmic male sterility (CMS)-based hybridization and recurrent bulk selection. Nine elite genotypes and two check cultivars entailed evaluation during 2020–2022 across three agroecological zones in Jember Regency, Indonesia. The tobacco genotypes Dark CK, Dark BK, and Dark AK exhibited considerable improvement in cured leaf yield (2.037 t ha^-1), cured leaf quality index (78.90), and crop index (151.68). Most tobacco genotypes enunciated remarkable resistance to P. nicotianae and R. solanacearum, though CMV susceptibility remains a challenge. Stability analysis identified four genotypes with consistent performance through genotype-by-environment interaction across diverse environments. The results provide considerable genetic basis and support for the development of export-oriented Kasturi cultivars and contribute to reducing dependency on tobacco imports in Indonesia.

Keywords: Kasturi tobacco (N. tabacum L.), recurrent selection, hybridization, genotype-by-environment interaction, disease resistance, cured leaf quality, yield stability

Key findings: The integration of CMS-based hybridization and recurrent selection successfully produced Kasturi tobacco (N. tabacum L.) genotypes with superior yield, better leaf quality, and disease resistance. Four tobacco genotypes revealed broad environmental adaptability, while one genotype showed specific adaptation. These genetic resources will enhance the productivity and export potential of sun-cured aromatic tobacco.

Stable and high-yielding rice (Oryza sativa L.) cultivars are essential for improving productivity in marginal environments such as Papua, Indonesia. Ten rice genotypes, including elite and advanced breeding lines, underwent evaluation across two contrasting sites—Muara (favorable) and Papua (suboptimal)—to estimate genetic variability, heritability, stability, and tolerance indices. Significant genotype-by-environment interactions were evident for key agronomic traits, particularly plant height, productive tiller number, and 1000-grain weight. Moderate to high heritability (H² = 0.593–0.745) indicated a strong genetic control, with the productive tiller number showing the greatest variability (GCV = 14.68%, PCV = 23.80%). Stability analyses using the Eberhart-Russell and AMMI (additive main-effects and multiplicative interaction) models identified the genotype 12F as highly adaptable and high yielding, 1F and 54F as broadly stable, and 58F and 44F as consistently stable under stress-prone conditions. The stress tolerance index (STI) supported these findings, confirming combined yield potential and environmental resilience. Although based on two locations, this study provides valuable preliminary insights for developing rice cultivars adapted to suboptimal agroecosystems.

Keywords: Adaptability, heritability, genotype stability, stress tolerance index, suboptimal agroecosystem

Key findings: Significant genotype-by-environment interactions were noteworthy for primary agronomic traits, underscoring the importance of multi-environment assessment of rice (O. sativa L.). Stability analysis identified 12F as the most promising genotype, providing high yields and considerable adaptability.

A multi-canopy cropping system—where short and tall rice (Oryza sativa L.) genotypes involve closer planting on the same hill—can considerably enhance the grain yield. Although the factors involved in this yield advantage have been the subject of intensive studies, the breeding of rice cultivars for such a cropping system remains at an early stage. The following study aimed to identify the effective breeding strategies for developing rice genotypes adapted to a multi-canopy system. Rice advanced lines totaling 35 from the F5 and F6 generations received evaluation under monoculture and multi-canopy systems. The field experiments, laid out in a randomized complete block design, had three replications in a multi-canopy and two in the monoculture. The multi-canopy system demonstrated more considerable sensitivity than monoculture in distinguishing genotypes’ performance and thus became identified as an ideal environment for selecting rice lines aimed for multi-canopy. For multi-canopy rice, the proposal for two primary selection strategies emerged, namely, sequential selection and simultaneous selection. For developing short genotypes, the key selection traits were plant height, the number of productive tillers, and filled grains per panicle. Under a multi-canopy system, the weighted index selection based on these traits proved to be effective in achieving the breeding objectives.

Keywords: Rice (O. sativa L.), selection strategy, complementary interaction, cropping system, selection differential, selection method, growth and yield traits

Key findings: The multi-canopy system emerged to be effective in differentiating the rice (O. sativa L.) genotypes’ performance targeted for this system, and the weighted index selection was considerably reliable for selecting suitable rice genotypes.

Besides the control treatment, Jabjabb date palm (Phoenix dactylifera L.) offshoots received irrigation water contaminated with heavy metals, lead(II) nitrate (Pb[NO3]2) = 300 mg kg^-1 and cadmium chloride (CdCl2) = 3 mmol. In addition to the control treatment, putrescine (500 mg L^-1), coumaric acid (500 mg L^-1), and 10 kg of palm^-1 zeolite entailed application to seedling soil. After nine months of alternately treating the seedlings with pollutants and therapies, preparing tissue slices of the study palm leaves succeeded. Lead and cadmium treatment adversely affected leaf anatomy and decreased epidermal, parenchymal, and vascular bundle markers to the lowest values. The study showed putrescine, coumaric acid, and zeolite improved leaf tissue anatomical properties and recorded the highest values. The enhancers reduced pollution, but putrescine improved the anatomical properties of leaves impacted by heavy metals, most especially lead. This interaction had the highest epidermis thickness, parenchymal cell diameter, primary and secondary xylem diameter, phloem thickness, bundle sheath thickness, vascular bundle length, and width (145.53, 214.17, 90.88, 77.13, 62.12, 30.21, 36.11, and 11.00 micrometers, respectively). By modulating the thickness of leaf tissue cuticles, the heavy metal factor and enhancers boosted the plant’s pollution resistance.

Keywords: Date palm (P. dactylifera L.), polyamines, zeolite, anatomical characteristics, palm offshoots, heavy elements, stress conditions

Key findings: Heavy metal pollution negatively affected the anatomical characteristics and showed decreased values of epidermal cells, parenchymal cells, and vascular bundles in leaf tissue of the date palm (P. dactylifera L.). Bioenhancers, such as putrescine, coumaric acid, and zeolite, improved the anatomical properties of leaf tissues.

This experiment transpired to determine the effect of the fungus Fusarium dimerum on the chlorophyll content and some phenotypic and anatomical morphological traits of the leaves of date palms (Phoenix dactylifera L.). The study results showed the ability of the fungus F. dimerum to cause infection on date palm leaves of five cultivars. The findings revealed that F. dimerum can secrete the enzymes cellulase, phenol oxidase, lipase, and amylases, as the area of their enzyme activity reached 6.1, 5.8, 6.2, and 12.4 mm, respectively. The results of histological analysis of the infected leaves also indicated the presence of F. dimerum spores in tissues of the infected leaves and the decomposition of cell walls and the loss of their integrated shape. The experiment showed significant differences in the chlorophyll content in healthy leaves and those infected with the fungus F. dimerum, wherein the percentage decreased in leaves infected with the fungus compared with the control treatment (healthy leaves).

Keywords: Date palm (P. dactylifera L.), Fusarium dimerum, histological anatomy, chlorophyll content in leaves, enzymes, fungal disease

Key findings: The results of the pathogenicity test for the fungus F. dimerum on the leaves of five cultivars of date palms (P. dactylifera L.) showed the ability of the fungus F. dimerum to cause infection and its ability to secrete the enzymes cellulase, phenol oxidase, lipase, and amylases. The ability to secrete enzymes plays a primary role in causing infection in the date palms.