Growth and antioxidant responses to water stress in eggplant MAGIC population parents, F1 hybrids and a subset of recombinant inbred lines.

BACKGROUND: The generation of new eggplant (Solanum melongena L.) cultivars with drought tolerance is a main challenge in the current context of climate change. In this study, the eight parents (seven of S. melongena and one of the wild relative S. incanum L.) of the first eggplant MAGIC (Multiparent Advanced Generation Intercrossing) population, together with four F1 hybrids amongst them, five S5 MAGIC recombinant inbred lines selected for their genetic diversity, and one commercial hybrid were evaluated in young plant stage under water stress conditions (30% field capacity; FC) and control conditions (100% FC). After a 21-day treatment period, growth and biomass traits, photosynthetic pigments, oxidative stress markers, antioxidant compounds, and proline content were evaluated. RESULTS: Significant effects (p < 0.05) were observed for genotype, water treatments and their interaction in most of the traits analyzed. The eight MAGIC population parental genotypes displayed a wide variation in their responses to water stress, with some of them exhibiting enhanced root development and reduced foliar biomass. The commercial hybrid had greater aerial growth compared to root growth. The four F1 hybrids among MAGIC parents differed in their performance, with some having significant positive or negative heterosis in several traits. The subset of five MAGIC lines displayed a wide diversity in their response to water stress. CONCLUSION: The results show that a large diversity for tolerance to drought is available among the eggplant MAGIC materials, which can contribute to developing drought-tolerant eggplant cultivars.

Improved genome assembly and pan-genome provide key insights into eggplant domestication and breeding.

Eggplant (Solanum melongena L.) is an important horticultural crop and one of the most widely grown vegetables from the Solanaceae family. It was domesticated from a wild, prickly progenitor carrying small, round, non-anthocyanic fruits. We obtained a novel, highly contiguous genome assembly of the eggplant '67/3' reference line, by Hi-C retrofitting of a previously released short read- and optical mapping-based assembly. The sizes of the 12 chromosomes and the fraction of anchored genes in the improved assembly were comparable to those of a chromosome-level assembly. We resequenced 23 accessions of S. melongena representative of the worldwide phenotypic, geographic, and genetic diversity of the species, and one each from the closely related species Solanum insanum and Solanum incanum. The eggplant pan-genome contained approximately 51.5 additional megabases and 816 additional genes compared with the reference genome, while the pan-plastome showed little genetic variation. We identified 53 selective sweeps related to fruit color, prickliness, and fruit shape in the nuclear genome, highlighting selection leading to the emergence of present-day S. melongena cultivars from its wild ancestors. Candidate genes underlying the selective sweeps included a MYBL1 repressor and CHALCONE ISOMERASE (for fruit color), homologs of Arabidopsis GLABRA1 and GLABROUS INFLORESCENCE STEMS2 (for prickliness), and orthologs of tomato FW2.2, OVATE, LOCULE NUMBER/WUSCHEL, SUPPRESSOR OF OVATE, and CELL SIZE REGULATOR (for fruit size/shape), further suggesting that selection for the latter trait relied on a common set of orthologous genes in tomato and eggplant.

A highly efficient organogenesis protocol based on zeatin riboside for in vitro regeneration of eggplant.

BACKGROUND: Efficient organogenesis induction in eggplant (Solanum melongena L.) is required for multiple in vitro culture applications. In this work, we aimed at developing a universal protocol for efficient in vitro regeneration of eggplant mainly based on the use of zeatin riboside (ZR). We evaluated the effect of seven combinations of ZR with indoleacetic acid (IAA) for organogenic regeneration in five genetically diverse S. melongena and one S. insanum L. accessions using two photoperiod conditions. In addition, the effect of six different concentrations of indolebutyric acid (IBA) in order to promote rooting was assessed to facilitate subsequent acclimatization of plants. The ploidy level of regenerated plants was studied. RESULTS: In a first experiment with accessions MEL1 and MEL3, significant (p < 0.05) differences were observed for the four factors evaluated for organogenesis from cotyledon, hypocotyl and leaf explants, with the best results obtained (9 and 11 shoots for MEL1 and MEL3, respectively) using cotyledon tissue, 16 h light / 8 h dark photoperiod conditions, and medium E6 (2 mg/L of ZR and 0 mg/L of IAA). The best combination of conditions was tested in the other four accessions and confirmed its high regeneration efficiency per explant when using both cotyledon and hypocotyl tissues. The best rooting media was R2 (1 mg/L IBA). The analysis of ploidy level revealed that between 25 and 50% of the regenerated plantlets were tetraploid. CONCLUSIONS: An efficient protocol for organogenesis of both cultivated and wild accessions of eggplant, based on the use of ZR, is proposed. The universal protocol developed may be useful for fostering in vitro culture applications in eggplant requiring regeneration of plants and, in addition, allows developing tetraploid plants without the need of antimitotic chemicals.

Indole-3-acetic acid promotes cadmium (Cd) accumulation in a Cd hyperaccumulator and a non-hyperaccumulator by different physiological responses.

To study the effects of indole-3-acetic acid (IAA) on cadmium (Cd) accumulation and the physiological responses of the Cd hyperaccumulator Solanum nigrum and non-hyperaccumulator Solanum melongena, a pot experiment was conducted in soil containing 2 mg kg-1 Cd in which different concentrations of IAA (0, 10, 20, or 40 mg L-1) were sprayed on plant leaves. The results showed that Cd accumulation in shoots of S. nigrum was significantly increased by 30% after the addition of 10 mg L-1 IAA under 2 mg kg-1 Cd stress compared to that in the control, but shoot Cd accumulation showed no significant change in S. melongena after this IAA treatment. Additionally, the growth and the proline content in the two species were significantly increased by 20 mg L-1 IAA. The activities of peroxidase and catalase in leaves of S. nigrum and the activity of superoxide dismutase (SOD) in S. melongena were significantly increased and their malondialdehyde content was significantly decreased compared to those in the control. The root activity of S. nigrum was significantly improved after 10 and 20 mg L-1 IAA treatments, but no significant difference was observed in S. melongena. The correlation analysis results showed that the Cd concentration in leaves of S. nigrum was significantly and positively correlated with the carotenoid and proline contents, and there was also a significant positive correlation between the Cd concentration and SOD activity in leaves of S. melongena. Therefore, S. nigrum is an ideal plant for the phytoextraction of Cd-contaminated soil assisted by IAA. IAA promotes Cd accumulation in plant shoots by enhancing the accumulation of carotenoids and proline in S. nigrum and maintaining a high leaf SOD activity in S. melongena.

Alkyl polyglycoside and earthworm (Eisenia fetida) enhance biodegradation of green waste and its use for growing vegetables.

Managing municipal green waste is a challenge to municipalities, partly because of the slow rate of decomposition of green waste during composting due to its high lignin and cellulose contents. Hence, this study evaluated the effect of alkyl polyglycoside (APG), a biosurfactant, and the earthworm Eisenia fetida on the composting process. Addition of APG and E. fetida significantly increased total bacteria, cellulolytic fungi, phosphate solubilizing bacteria and nitrogen fixing bacteria populations, and the activities of cellulase, urease and alkaline phosphatase in composts as compared with the control. The APG and earthworm treatments also increased surface roughness and porosity of the green waste; Compared with control, APG and earthworm addition increased the degradation rate of TOC, lignin and cellulose by 5.9-17.9, 10.3-32.0 and 10.8-18.8%, respectively, and resulted in better compost quality, as was reflected in the neutral pH, higher cation exchange capacity (CEC) and nutrient concentrations (N, P, K, Ca, Mg, Fe, Cu, Zn, Mn). Final germination percentage and growth rate of tomato, eggplant and pepper seedlings were higher (P < 0.05) or similar in all composts produced with the addition of APG and earthworm, while plant growth was lower (P < 0.05) in the compost produced with the control than in peat substrate. The combination of APG+E. fetida enhanced the decomposition of green waste and improved final compost quality the most. Further research is needed to determine the best level of APG addition and optimum earthworm density for composting green waste.

Image-based dynamic quantification and high-accuracy 3D evaluation of canopy structure of plant populations.

Background and Aims: Global agriculture is facing the challenge of a phenotyping bottleneck due to large-scale screening/breeding experiments with improved breeds. Phenotypic analysis with high-throughput, high-accuracy and low-cost technologies has therefore become urgent. Recent advances in image-based 3D reconstruction offer the opportunity of high-throughput phenotyping. The main aim of this study was to quantify and evaluate the canopy structure of plant populations in two and three dimensions based on the multi-view stereo (MVS) approach, and to monitor plant growth and development from seedling stage to fruiting stage. Methods: Multi-view images of flat-leaf cucumber, small-leaf pepper and curly-leaf eggplant were obtained by moving a camera around the plant canopy. Three-dimensional point clouds were reconstructed from images based on the MVS approach and were then converted into surfaces with triangular facets. Phenotypic parameters, including leaf length, leaf width, leaf area, plant height and maximum canopy width, were calculated from reconstructed surfaces. Accurate evaluation in 2D and 3D for individual leaves was performed by comparing reconstructed phenotypic parameters with referenced values and by calculating the Hausdorff distance, i.e. the mean distance between two surfaces. Key Results: Our analysis demonstrates that there were good agreements in leaf parameters between referenced and estimated values. A high level of overlap was also found between surfaces of image-based reconstructions and laser scanning. Accuracy of 3D reconstruction of curly-leaf plants was relatively lower than that of flat-leaf plants. Plant height of three plants and maximum canopy width of cucumber and pepper showed an increasing trend during the 70 d after transplanting. Maximum canopy width of eggplants reached its peak at the 40th day after transplanting. The larger leaf phenotypic parameters of cucumber were mostly found at the middle-upper leaf position. Conclusions: High-accuracy 3D evaluation of reconstruction quality indicated that dynamic capture of the 3D canopy based on the MVS approach can be potentially used in 3D phenotyping for applications in breeding and field management.

Promoting the productivity and quality of brinjal aligned with heavy metals immobilization in a wastewater irrigated heavy metal polluted soil with biochar and chitosan.

Depleting aquifers, lack of planning and low socioeconomic status of Pakistani farmers have led them to use wastewater (WW) for irrigating their crops causing food contamination with heavy metals and ultimately negative effects on human health. This study evaluates the effects of chitosan (CH) and biochar (BC) on growth and nutritional quality of brinjal plant together with in situ immobilization of heavy metals in a soil polluted with heavy metals due to irrigation with wastewater (SPHIW) and further irrigated with the same WW. Both CH and BC were applied at three different rates i.e. low rate [(LR), BC0.5%, CH0.5% and BC0.25%+CH0.25%], medium rate [(MR), BC1%, CH1% and BC0.5%+CH0.5%] and high rate [(HR), BC1.5%, CH1.5% and BC0.75%+CH0.75%]. Result revealed that brinjal growth, antioxidant enzymes, and fruit nutritional quality significantly improved from LR to HR for each amendment, relative to control. However, these results were more prominent with BC alone and BC+CH, compared with CH alone at each rate. Similarly, with few exceptions, significant reduction in Ni, Cd, Co, Cr and Pb concentrations in the root, shoot and fruit were found in sole CH treatment both at LR and MR but in both CH and BC+CH treatments at HR, relative to control. Interestingly, the concentrations of Fe in the roots, shoots and fruit were more pronounced at BC treatments relative to CH and BC+CH treatments at each rate, compared to control. Overall, the BC+CH treatment at HR was the most effective treatment for in situ immobilization of heavy metals in SPHIW and further irrigated with the same WW, compared to rest of the treatments. This study indicates that BC0.75%+CH0.75% treatment can be used to reduce mobility and bioavailability of heavy metals in SPHIW and facilitates plant growth by improving the antioxidant system. However, the feasibility of BC0.75%+CH0.75% treatment should also be tested at the field scale.

Metabolomic analyses to evaluate the effect of drought stress on selected African Eggplant accessions.

BACKGROUND: Drought stress is one of the main abiotic stresses that affect crops. It leads to biochemical changes that can have adverse effects on plant growth, development and productivity. African eggplants are important vegetable and fruit crops reported to adapt and thrive well under drought stress. The diversified metabolites arising due to stress have not been well defined. A gas chromatographic-mass spectrometric metabolomic approach was applied to characterize the effect of drought stress on metabolites at different stages of growth. Nineteen accessions were selected for analysis and drought was imposed by withholding water until soil moisture reached 60% field capacity. Fresh leaf tissues were sampled before stress, 2 and 4 weeks after stress and metabolite profiling done. RESULTS: Significant changes in metabolite content were observed, and potentially important metabolites with respect to stress responses were characterized. Proline, glutamate, sucrose, fructose and tricarboxylic acid cycle metabolites were shown to be positively correlated with stress. Principal component analysis showed a clear discrimination between the different accessions, growth stages and stress/control conditions. CONCLUSION: The results illustrate that drought stress has a significant impact on the concentrations of some metabolites, such as amino acids, sugars and organic acids, which may contribute to drought stress effects and tolerance. © 2017 Society of Chemical Industry.

Nutritional value and antioxidant content of seed-containing and seedless eggplant fruits of two cultivars grown under protected cultivation during autumn-winter and spring-summer.

BACKGROUND: Due to their low carbohydrate and high antioxidant content, eggplants are beneficial for the human diet. At <15 °C, pollen production and fertility are reduced and plant-growth regulators may be used to set seedless fruit. Because only the agronomic effects of hormone are well-documented, we investigated the composition and metabolism during the development/maturation of seed-containing and seedless fruits of two cultivars grown over two seasons. RESULTS: The respiration rate of both seedless and seed-containing fruit decreased with development and maturation. In seedless fruit, starch content decreased at market maturity, whereas in seed-containing fruit starch increased. Respiration and starch were higher in spring-summer than in autumn-winter. Disaccharides were highest at market maturity, with sucrose generally higher in seed-containing fruit; monosaccharides were variable and protein content was reduced in seedless fruit. Phenols closely correlated with antioxidant activity and decreased with development; at market maturity in spring-summer phenols were higher in seedless fruit (Tsakoniki) or unaffected (Emi). Polyphenol oxidase and peroxidase activities were mostly higher in seed-containing fruit, but browning was higher in seedless fruit. CONCLUSIONS: Notwithstanding reduced protein and increased browning, seedless fruit at market maturity presented less starch, hence fewer calories, and more antioxidants (phenols) for the human diet than the corresponding seed-containing fruit. © 2017 Society of Chemical Industry.

Identification and characterization of CBL and CIPK gene families in eggplant (Solanum melongena L.).

Eggplant (Solanum melongena L.) is an edible vegetable cultivated and consumed worldwide. But the production of eggplant is significantly limited by the soil salinization in greenhouse cultivation system. The main ions are Na(+), Ca(2+), Mg(2+), K(+), Cl(-), and SO4 (2-) in the salty soils. Calcineurin B-like proteins (CBLs) are calcium sensors and control the affinities and activities of numerous ion transporters with CBL-interacting protein kinases (CIPKs). In this study, a total of 5 CBL and 15 CIPK genes from eggplant were identified first. The yeast two-hybrid (Y2H) assay and bimolecular fluorescence complementation (BiFC) assay demonstrated the interaction network between SmCBLs and SmCIPKs. Strikingly, some new CBL-CIPK complexes were found which have never been discovered in any other plant species. The expression level of each SmCBL or SmCIPK under 200 mM NaCl, low potassium (LK; 100 µM), high Mg with 20 mM MgCl2 and MgSO4 stresses were examined by quantitative real-time PCR (qRT-PCR) assay and these CBL and CIPK genes were found to respond to the four ion stresses differently. Interestingly, the differential expression level of SmCIPK3, -24 or -25 to Mg(2+) is higher than Na(+), and Cl(-) is higher than SO4 (2-). In addition, different magnesium salt can induce different response mechanisms in eggplant. In summary, this study provides insight into the characterization of CBLs and CIPKs in eggplant. It may be used in a novel biotechnological breeding program strategy to create new eggplant cultivars, leading to enhance different ion tolerance.

Diversity of wild bees supports pollination services in an urbanized landscape.

Plantings in residential neighborhoods can support wild pollinators. However, it is unknown how effectively wild pollinators maintain pollination services in small, urban gardens with diverse floral resources. We used a 'mobile garden' experimental design, whereby potted plants of cucumber, eggplant, and purple coneflower were brought to 30 residential yards in Chicago, IL, USA, to enable direct assessment of pollination services provided by wild pollinator communities. We measured fruit and seed set and investigated the effect of within-yard characteristics and adjacent floral resources on plant pollination. Increased pollinator visitation and taxonomic richness generally led to increases in fruit and seed set for all focal plants. Furthermore, fruit and seed set were correlated across the three species, suggesting that pollination services vary across the landscape in ways that are consistent among different plant species. Plant species varied in terms of which pollinator groups provided the most visits and benefit for pollination. Cucumber pollination was linked to visitation by small sweat bees (Lasioglossum spp.), whereas eggplant pollination was linked to visits by bumble bees. Purple coneflower was visited by the most diverse group of pollinators and, perhaps due to this phenomenon, was more effectively pollinated in florally-rich gardens. Our results demonstrate how a diversity of wild bees supports pollination of multiple plant species, highlighting the importance of pollinator conservation within cities. Non-crop resources should continue to be planted in urban gardens, as these resources have a neutral and potentially positive effect on crop pollination.

Exogenous proline application ameliorates toxic effects of arsenate in Solanum melongena L. seedlings.

Hydroponic experiments were conducted to investigate an effect of exogenous application of proline (Pro; 25 µM) in alleviating arsenate (As(V); 5 and 25 µM) toxicity in Solanum melongena L. (eggplant) seedlings. Exposure of As(V) declined growth of eggplant, which was coincided with an enhanced accumulation of As. However, exogenous Pro application alleviated As(V) toxicity in eggplant seedlings by reducing the accumulation of As. The fluorescence characteristics (JIP-test): φP0, Ψ0, φE0, PIABS, ABS/RC, TR0/RC, ET0/RC, DI0/RC, NPQ and qP were also affected by As(V). However, the effects of As(V) were more prominent on PIABS DI0/RC and NPQ. In Pro treated seedlings, following parameters viz. φP0, Ψ0, φE0 and PIABS were stimulated, while, energy flux parameters (ABS/RC, TR0/RC, ET0/RC and DI0/RC) were inhibited. Toxic effects of As(V) on photochemistry of photosystem II (PS II) were ameliorated by an exogenous application of Pro. Oxidative stress markers: superoxide radical, hydrogen peroxide and malondialdehyde (lipid peroxidation) were enhanced by As(V) exposure, however, their levels were significantly diminished by an exogenous application of Pro. Treatment of As(V) stimulated the activities of superoxide dismutase, peroxidase and catalase except that of glutathione-S-transferase. Exogenous Pro application improved the activities of enzymatic antioxidants. The level of endogenous Pro was higher in As(V) treated as well as in Pro fed seedlings. The activity of a key enzyme of Pro biosynthesis: Δ(1)-pyrroline-5-carboxylate synthetase was higher in Pro fed seedlings. The activity of Pro dehydrogenase was inhibited under As(V) stress, and its activity was minimum in case of Pro+As(V) combination. These results indicate that Pro metabolism could play a key role in regulating the accumulation of As and levels of antioxidants, which concomitantly result into a better growth of eggplant seedlings when compared to the As(V) treatments alone.

Effect of Number of Bombus impatiens (Hymenoptera: Apidae) Visits on Eggplant Yield.

Eggplant (Solanum melongena L.) is a crop with perfect flowers capable of self-pollination. Insect pollination enhances fruit set, but little is known about how pollination success varies by number of visits from bumble bees. To quantify the efficiency of bumble bees at pollinating eggplants, we allowed 1, 2, 6, and 12 bumble bees (Bombus impatiens Cresson) to visit eggplant flowers and compared percentage of flowers that set fruit, fruit weight, and seed set after 3 wk. We compared yield from these visit numbers to eggplant flowers that were left open for unlimited visitation. Eggplant flowers set the most fruit from open-pollination and 12 visits. Larger, seedier fruits were formed in open-pollinated flowers. However, fruit characteristics in the 12 visit treatment were similar to lower visitation frequencies. We confirm B. impatiens as an efficient eggplant pollinator and document the greatest benefit from 12 bumble bee visits and open-pollinated flowers. To maintain effective eggplant pollination, local conditions must be conducive for bumble bee colony establishment and repeated pollen foraging trips.

Plant growth-promoting potential of bacteria isolated from active volcano sites of Barren Island, India.

UNLABELLED: To elucidate the biodiversity of plant growth-promoting (PGP) bacteria in active volcano sites of Barren Island, India, a total of 102 bacteria were isolated and screened for their multifunctional PGP properties. The results revealed that 21 isolates (20.6%) survived heat shock at 72°C and 11 (10.8%) isolates were able to grow exposed to 25% NaCl (w/v). In assaying for PGP properties, 59 (57.8%) isolates shown indole acetic acid (IAA) like substances production, 57 isolates (55.9%) produced siderophore and 34 (33.3%) solubilized inorganic phosphate qualitatively. Whereas in the production of extracellular enzymes, 42 isolates (41.2%) produced protease and amylase, 26 (25.5%) isolates produced lipase and 24 (23.5%) isolates produced cellulase. In antagonistic activity, 30 isolates (29.4%) were found antagonistic against Macrophomina sp., 20 isolates (19.6%) against Rhizoctonia solani and 15 isolates (14.7%) against Sclerotium rolfsii. The results based on 16 rRNA gene sequencing revealed that the PGP bacteria belonged to 22 different species comprising 13 genera. Based on multifunctional properties, nine isolates were further selected to determine the PGP in brinjal and chilli seeds. Of the bacteria tested, the isolate BAN87 showed increased root and shoot length of both the crops followed in plant growth promotion by BAN86 and BAN43. The outcome of this research proves plausible practical applicability of these PGPB for crop production in soils of saline and arid environments. SIGNIFICANCE AND IMPACT OF THE STUDY: The present research shows diverse plant growth-promoting (PGP) bacteria could be isolated from the active volcano site and suggests that volcano sites represent an ecological niche, which harbours a diverse and hitherto largely uncharacterized microbial population with yet unknown and untapped potential biotechnological applications, for example, plant growth promoters, as evidenced from this study. The outcome of this research may have a practical effect on crop production methodologies in saline and arid environment soils.

Eggplant fruit composition as affected by the cultivation environment and genetic constitution.

BACKGROUND: No comprehensive reports exist on the combined effects of season, cultivation environment and genotype on eggplant (Solanum melongena) composition. We studied proximate composition, carbohydrates, total phenolics and vitamin C of eggplant fruits of three Spanish landraces, three commercial hybrids and three hybrids between landraces cultivated across two environmental conditions (open field, OF; and, greenhouse, GH) for up to four seasons. RESULTS: Season (S) had a larger effect than the genotype (G) for composition traits, except for total phenolics. G × S interaction was generally of low relative magnitude. Orthogonal decomposition of the season effect showed that differences within OF or GH environments were in many instances greater than those between OF and GH. Spanish landraces presented, on average, lower contents of total carbohydrates and starch and higher contents of total vitamin C, ascorbic acid, and total phenolics than commercial hybrids. Hybrids among landraces presented variable levels of heterosis for composition traits. Genotypes grown in the same season cluster together on the graph of multivariate principal components analysis. CONCLUSION: The cultivation environment has a major role in determining the composition of eggplant fruits. Environmental and genotypic differences can be exploited to obtain high quality eggplant fruits.

Establishment of an in vitro plantlet regeneration protocol for unique varieties of brinjal (Solanum melongena L.) var. Mattu Gulla and Perampalli Gulla.

Brinjal (Solanum melongena L.) var. Mattu Gulla (MG) and var. Perampalli Gulla (PG) are unique varieties with distinct flavour cultivated in Udupi, Karnataka State, and are exposed to several biotic and abiotic stresses. An efficient and reproducible in vitro regeneration method is required to expedite the manipulation of these brinjal varieties to cope up with stress by tissue culture and gene transfer methods. The present study, reports a rapid and efficient in vitro regeneration protocol for these two varieties. The in vitro growth response was studied on Murashige and Skoog (MS) medium supplemented with 2, 4-D, BAP and IAA, and the plantlets were regenerated efficiently from callus cultures of leaf, cotyledon and hypocotyl explants. Among the three explants, the hypocotyl explants were found to have better callus induction and multiple shoot regeneration. High frequency of shoot initiation was achieved from hypocotyl derived calluses in MS media with 2.0 mg/L BAP and 0.5 mg/L IAA in MG and PG. Efficient and rapid shoot proliferation, and elongation were noted in MS medium with 1.0 mg/L BAP and 0.3 mg/L GA3. The in vitro regenerated shoots produced healthy roots when they were cultured on MS medium supplemented with 0.5 mg/L IBA. A significant difference was observed in percentage of callus induction, number of shoots per callus, shoot elongation and number of hardened plantlets of MG and PG. MG showed maximum response in all stages of culture than PG. Hardening of plantlets in tissue culture was achieved in three weeks. The hardened plantlets were grown in pots for further acclimatization in green house and finally transplanted to experimental garden where they developed into flowering plants and produced mature fruits with viable seeds.

Diversity of soil fungi in North 24 Parganas and their antagonistic potential against Leucinodes orbonalis Guen. (Shoot and fruit borer of brinjal).

Soil samples were collected from agricultural fields and gardens in North 24 Parganas, West Bengal, and fungi species were isolated from them. Thirty-one fungal species were isolated with 19 found in agricultural soil and 28 in garden soil. Twenty-eight out of 31 were identified using cultural and microscopic characters, and three were unidentified. The diversity of isolated fungi was calculated by Simpson's diversity index. The garden soil possessed more fungal colonies (750) than agricultural soil (477). In agricultural soil, the dominant fungi were Aspergillus niger, Rhizopus oryzae, and Penicillium expansum, and the dominant fungi of garden soil were A. niger and Fusarium moniliforme. Simpson's diversity index indicated that garden soil had more fungal diversity (0.939) than agricultural soil (0.896). The entomopathogenic capacity of the isolated fungi was tested against the brinjal shoot and fruit borer (Leucinodes orbonalis Guen) which is the major insect pest of brinjal. The isolated fungi were screened against larva of L. orbonalis for their entomopathogenic potential. Beauveria bassiana, A. niger, and P. expansum showed appreciable antagonism to L. orbonalis, and their lethal doses with 50 % mortality (LD50s) were 4.0 × 10(7), 9.06 × 10(7), and 1.50 × 10(8) spore/mL, respectively, and their times taken to reach 50 % mortality (LT50s) were 9.77, 10.56, and 10.60 days, respectively. This work suggests the restriction of chemical pesticide application in agricultural fields to increase fungal diversity. The entomopathogenic efficacy of B. bassiana could be used in agricultural fields to increase fugal diversity and protect the brinjal crop.

Deep learning-based prediction of plant height and crown area of vegetable crops using LiDAR point cloud.

Remote sensing has been increasingly used in precision agriculture. Buoyed by the developments in the miniaturization of sensors and platforms, contemporary remote sensing offers data at resolutions finer enough to respond to within-farm variations. LiDAR point cloud, offers features amenable to modelling structural parameters of crops. Early prediction of crop growth parameters helps farmers and other stakeholders dynamically manage farming activities. The objective of this work is the development and application of a deep learning framework to predict plant-level crop height and crown area at different growth stages for vegetable crops. LiDAR point clouds were acquired using a terrestrial laser scanner on five dates during the growth cycles of tomato, eggplant and cabbage on the experimental research farms of the University of Agricultural Sciences, Bengaluru, India. We implemented a hybrid deep learning framework combining distinct features of long-term short memory (LSTM) and Gated Recurrent Unit (GRU) for the predictions of plant height and crown area. The predictions are validated with reference ground truth measurements. These predictions were validated against ground truth measurements. The findings demonstrate that plant-level structural parameters can be predicted well ahead of crop growth stages with around 80% accuracy. Notably, the LSTM and the GRU models exhibited limitations in capturing variations in structural parameters. Conversely, the hybrid model offered significantly improved predictions, particularly for crown area, with error rates for height prediction ranging from 5 to 12%, with deviations exhibiting a more balanced distribution between overestimation and underestimation This approach effectively captured the inherent temporal growth pattern of the crops, highlighting the potential of deep learning for precision agriculture applications. However, the prediction quality is relatively low at the advanced growth stage, closer to the harvest. In contrast, the prediction quality is stable across the three different crops. The results indicate the presence of a robust relationship between the features of the LiDAR point cloud and the auto-feature map of the deep learning methods adapted for plant-level crop structural characterization. This approach effectively captured the inherent temporal growth pattern of the crops, highlighting the potential of deep learning for precision agriculture applications.

Identification of Quantitative Trait Loci and Candidate Genes Controlling Seed Dormancy in Eggplant (Solanum melongena L.).

Seed dormancy is a life adaptation trait exhibited by plants in response to environmental changes during their growth and development. The dormancy of commercial seeds is the key factor affecting seed quality. Eggplant seed dormancy is controlled by quantitative trait loci (QTLs), but reliable QTLs related to eggplant dormancy are still lacking. In this study, F2 populations obtained through the hybridization of paternally inbred lines with significant differences in dormancy were used to detect regulatory sites of dormancy in eggplant seeds. Three QTLs (dr1.1, dr2.1, and dr6.1) related to seed dormancy were detected on three chromosomes of eggplant using the QTL-Seq technique. By combining nonsynonymous sites within the candidate regions and gene functional annotation analysis, nine candidate genes were selected from three QTL candidate regions. According to the germination results on the eighth day, the male parent was not dormant, but the female parent was dormant. Quantitative real-time polymerase chain reaction (qRT-PCR) was used to verify the expression of nine candidate genes, and the Smechr0201082 gene showed roughly the same trend as that in the phenotypic data. We proposed Smechr0201082 as the potential key gene involved in regulating the dormancy of eggplant seeds. The results of seed experiments with different concentrations of gibberellin A3 (GA3) showed that, within a certain range, the higher the gibberellin concentration, the earlier the emergence and the higher the germination rate. However, higher concentrations of GA3 may have potential effects on eggplant seedlings. We suggest the use of GA3 at a concentration of 200-250 mg·L-1 to treat dormant seeds. This study provides a foundation for the further exploration of genes related to the regulation of seed dormancy and the elucidation of the molecular mechanism of eggplant seed dormancy and germination.

Amelioration of phytotoxic impact of biosynthesized zinc oxide nanoparticles: Plant growth promoting rhizobacteria facilitates the growth and biochemical responses of Eggplant (Solanum melongena) under nanoparticles stress.

The consistently increasing use of zinc oxide nanoparticles (ZnONPs) in crop optimization practices and their persistence in agro-environment necessitate expounding their influence on sustainable agro-environment. Attempts have been made to understand nanoparticle-plant beneficial bacteria (PBB)- plant interactions; the knowledge of toxic impact of nanomaterials on soil-PBB-vegetable systems and alleviating nanotoxicity using PBB is scarce and inconsistent. This study aims at bio-fabrication of ZnONPs from Rosa indica petal extracts and investigates the impact of PBB on growth and biochemical responses of biofertilized eggplants exposed to phyto-synthesized nano-ZnO. Microscopic and spectroscopic techniques revealed nanostructure, triangular shape, size 32.5 nm, and different functional groups of ZnONPs and petal extracts. Inoculation of Pseudomonas fluorescens and Azotobacter chroococcum improved germination efficiency by 22% and 18% and vegetative growth of eggplants by 14% and 15% under NPs stress. Bio-inoculation enhanced total chlorophyll content by 36% and 14 %, increasing further with higher ZnONP concentrations. Superoxide dismutase and catalase activity in nano-ZnO and P. fluorescens inoculated eggplant shoots reduced by 15-23% and 9-11%. Moreover, in situ experiment unveiled distortion and accumulation of NPs in roots revealed by scanning electron microscope and confocal laser microscope. The present study highlights the phytotoxicity of biosynthesized ZnONPs to eggplants and demonstrates that PBB improved agronomic traits of eggplants while declining phytochemicals and antioxidant levels. These findings suggest that P. fluorescens and A. chroococcum, with NPs ameliorative activity, can be cost-effective and environment-friendly strategy for alleviating NPs toxicity and promoting eggplant production under abiotic stress, fulfilling vegetable demands.