Nagachandrabose Seenivasan

BACKGROUND: Eco‐friendly management of Meloidogyne incognita remains a major challenge. Although several plant‐origin bioactive compounds (POBCs) have shown efficacy against M. incognita , comparative evaluation to identify priority candidates for formulation and validation remains limited. This study evaluated bio‐efficacy and potential interaction profiles of 16 POBCs against M. incognita through in vitro , glasshouse and in silico approaches. RESULTS: At 500 μg mL ⁻¹ , isothiocyanates (allyl‐ and 2‐phenylethyl isothiocyanate) and several aldehydes (benzaldehyde, cinnamaldehyde, p ‐anisaldehyde, trans ‐cinnamaldehyde) reported strong ovicidal (88–100% egg mortality at 72 h) and nematicidal (100% J ₂ mortality at 24 h) responses. Median lethal concentration (LC ₅₀ ) values across POBCs ranged widely (1.1–2635.6 μg mL ⁻¹ ), with isothiocyanates and aldehydes showing the lowest LC ₅₀ (1.1–34.5 μg mL ⁻¹ ) and fatty acids the highest (1441.3–2635.6 μg mL ⁻¹ ). Micromorphological observations of treated J ₂ revealed translucency changes, straightened posture and progressive intestinal vacuolation after exposure to isothiocyanates, aldehydes and eugenol. Further bioassays confirmed contact and volatile activity for isothiocyanates and aldehydes. Soil drenching at 500 μg mL ⁻¹ reduced number of eggs (71.2–92.5%) and adult females per root system (58.3–86.1%), as well as J ₂ in soil (62.2–84.8%), and produced lowest gall index (1.67–2.33). Molecular docking against six M. incognita protein targets (Gst‐1, AChE, Col‐1, Msp‐32, Vsp‐2, Hsp‐90) showed favorable binding energies (−2.8 to −8.3 kcal mol ⁻¹ ), with H‐bond formation suggesting that potential multitarget interactions may contribute to nematicidal activity. CONCLUSION: This study demonstrates that isothiocyanate‐ and aldehyde‐based POBCs are most promising candidates for developing eco‐friendly nematicides and warrant further biochemical validation, formulation, dose optimization, and field evaluation. © 2026 Society of Chemical Industry.

The genus Musa comprises 70–75 species with diverse ploidy levels. The widely cultivated edible banana (Musa paradisiaca L., family Musaceae) is a hybrid of the diploid species M. acuminata and M. ...

An investigation was undertaken to examine the genetic parameters of tomato (Solanum lycopersicum L.), along with path and correlation analyses, to improve yield and quality attributes utilizing 16 quantitative and qualitative indicators in the F2 population of a double cross hybrid (H1), comprising 250 plants. The results of the investigation revealed a high coefficient of variation (both phenotypic (PCV) and genotypic (GCV)), coupled with high heritability (>95%) in traits such as average fruit weight (SFW), number of fruits/clusters (NFC), and lycopene content (LC). The selection of these traits suggests a strong potential for genetic improvement. The correlation analysis showed a strong and significant association with yield and its contributing traits, like the weight of the single fruit (0.869), followed by the height of the plant(0.843) and the number of fruits/plant(0.793). Path analysis also showed a substantial direct effect on yield from the number of fruits/plant (0.419) and weight of single fruit (0.416). This study's selection of these traits insights valuable breeding strategies for developing tomato varieties with high yield and enhanced nutritional quality.

Tomato (Solanum lycopersicum L.) is the most prevalent and consumed vegetable crop worldwide because of its higher nutritional content. This study investigates the genetic diversity, principal components, correlations, clustering and heterosis among yield and quality traits of tomato parents and hybrids. Sixteen yield and quality-related attributes were evaluated using a diverse set of parents and their hybrids, revealing significant variation. The principal component analysis identified five principal components explaining 78.67% of the total variance, with a bi-plot highlighting the distribution of parents and hybrids. Five parents (CBESL159, CBESL169, CBESL162, CBESL164, CBESL168), two hybrids (H4, H5) and two double hybrids (H4xH5 and H5xH7) demonstrated widespread dispersion, indicating substantial genetic diversity driven primarily by yield and yield-related traits. The evaluation of heterosis among the hybrids revealed that six hybrids (H1, H3, H4, H5, H7 and H8) and four double hybrids (H5xH7, H1xH5, H8xH7 and H4xH5) exhibited significantly positive heterosis over the standard check hybrids.Further, the study underscores the potential of parents and hybrids for developing strong hybrid vigour regarding growth, yield, and quality characteristics. The number of fruits per plant, single fruit weight and overall fruit yield exhibited strong positive correlations, signifying their implication as indirect selection criteria in tomato breeding programs. These findings provide valuable insights for further breeding programmes to enhance tomato yield and quality through targeted hybridization and trait selection.

Summary: Purpureocillium lilacinum is a potent biocontrol agent against Meloidogyne spp. and various other plant-parasitic nematodes in crops. However, existing commercial formulations of P. lilacinum suffer from drawbacks like short shelf life and inconsistent performance in different environmental conditions. To address these issues, a new nano-formulation of P. lilacinum was developed and tested against Meloidogyne incognita infecting tomatoes. Initially, edible oil-based emulsions were prepared using probe ultrasonication, with 40 formulations screened and 14 selected for further testing. Seven of these emulsions remained stable at room temperature (28 ± 4°C) for 8 weeks, with stability assessed based on particle size, zeta potential, and particle shape using particle size analysis and transmission electron microscopy (TEM). Among these, NE 8 (comprising 10 ml of 1% carboxyl methyl cellulose (CMC), 1.25 ml of Tween 80 and 5 ml of sunflower oil) exhibited superior characteristics, with an average particle size of 226.6 nm, a zeta potential of −54.80 mV, and a spherical morphology under TEM examination. The P. lilacinum nanoemulsion formulation was produced by homogenising NE 8 emulsion and spores at a 1:1 ratio, ensuring efficient spore dispersion and encapsulation without loss of viability. In vitro tests demonstrated 100% immobility of M. incognita second-stage juveniles (J2) and 100% parasitism of eggs at a concentration of 5.0 ml l⁻¹. Under glasshouse conditions, soil drenching with the nano-formulation at concentrations ranging from 0.5 to 5.0 ml l⁻¹ resulted in enhanced tomato growth and significant suppression of M. incognita populations in soil and roots, with increased egg mass parasitism. Bio-safety tests confirmed that P. lilacinum nano-formulation at concentrations of 0.25 ml l⁻¹ and 5.0 ml l⁻¹ had no harmful effects on the earthworm Eudrilus eugeniae.

Rice (Oryza sativa L.) is one of the most widely grown crops in the world, and is a staple food for more than half of the global total population. Root-knot nematodes (RKNs), Meloidogyne spp., and especially M. graminicola, seem to be significant rice pests, which makes them the most economically important plant-parasitic nematode in this crop. RKNs develop a feeding site in galls by causing host cells to differentiate into hypertrophied, multinucleate, metabolically active cells known as giant cells. This grazing framework gives the nematode a constant food source, permitting it to develop into a fecund female and complete its life cycle inside the host root. M. graminicola effector proteins involved in nematode parasitism, including pioneer genes, were functionally characterized in earlier studies. Molecular modelling and docking studies were performed on Meloidogyne graminicola protein targets, such as β-1,4-endoglucanase, pectate lyase, phospholipase B-like protein, and G protein-coupled receptor kinase, to understand the binding affinity of Beta-D-Galacturonic Acid, 2,6,10,15,19,23-hexamethyltetracosane, (2S)-2-amino-3-phenylpropanoic acid, and 4-O-Beta-D-Galactopyranosyl-Alpha-D-Glucopyranose against ligand molecules of rice. This study discovered important molecular aspects of plant–nematode interaction and candidate effector proteins that were regulated by M. graminicola-infected rice plants. To the best of our knowledge, this is the first study to describe M. graminicola’s molecular adaptation to host parasitism.