Solanum Melongena Cv Research Articles

Effect of Organic Manures and Bio-fertilizers on Vegetative and Yield Parameters of Brinjal (Solanum melongena) cv. Pant Rituraj

field experiment was conducted to determine the effect of organic manures and bio-fertilizers on vegetative and yield parameters of brinjal (Solanum melongena) cv. Pant Rituraj at Crop Cafeteria, Galgotias University, Grater Noida. The experimental field was laid out in randomized block design (RBD) with three replications. The experimental treatments comprised of three organic manures viz. Farmyard Manure, Vermicompost and poultry manure in combination with two bio-fertilizers, namely Azospirillumand Phosphate Solubilizing Bacteria (PSB). All variable parameters regarding vegetative and yield were significantly influenced by different combinations of organic manures and bio-fertilizers. Result indicated that a combined application of organic manure and bio-fertilizers i.e.Vermicompost (50%) + Poultry manure (50%) + Azospirillumgave the significantly better response in respect to vegetative parameters and yield parameters and maximum plant height, number of branches per plant, number of leaves per plant, number of fruits per plant, fruit length, fruit diameter, fruit weight and yield were recorded under the same treatment.

Role of Trehalose Synthesis in Ralstonia syzygii subsp. indonesiensis PW1001 in Inducing Hypersensitive Response on Eggplant (Solanum melongena cv. Senryo-nigou).

Ralstonia syzygii subsp. indonesiensis (Rsi, former name: Ralstonia solanacearum phylotype IV) PW1001, a causal agent of potato wilt disease, induces hypersensitive response (HR) on its non-host eggplant (Solanum melongena cv. Senryo-nigou). The disaccharide trehalose is involved in abiotic and biotic stress tolerance in many organisms. We found that trehalose is required for eliciting HR on eggplant by plant pathogen Rsi PW1001. In R. solanacearum, it is known that the OtsA/ OtsB pathway is the dominant trehalose synthesis pathway, and otsA and otsB encode trehalose-6-phosphate (T6P) synthase and T6P phosphatase, respectively. We generated otsA and otsB mutant strains and found that these mutant strains reduced the bacterial trehalose concentration and HR induction on eggplant leaves compared to wild-type. Trehalose functions intracellularly in Rsi PW1001 because addition of exogenous trehalose did not affect the HR level and ion leakage. Requirement of trehalose in HR induction is not common in R. solanacearum species complex because mutation of otsA in Ralstonia pseudosolanacearum (former name: Ralstonia solanacearum phylotype I) RS1002 did not affect HR on the leaves of its non-host tobacco and wild eggplant Solanum torvum. Further, we also found that each otsA and otsB mutant had reduced ability to grow in a medium containing NaCl and sucrose, indicating that trehalose also has an important role in osmotic stress tolerance.

Hydrogen sulfide and phenylalanine alleviate chilling injury in eggplant fruits during cold storage by enhancing antioxidant activities and membrane stability

In this experiment, the exogenous application of hydrogen sulfide (H2S; 1, 2 or 3 mM) and phenylalanine (PA; 2.5, 5, or 7.5 mM) to alleviate chilling injury and enhancing antioxidant activity and membrane stability of eggplant fruits (Solanum melongena cv. Hadrian) during storage at 7℃ for 21 days was investigated. Results indicated that H2S and PA alleviated chilling injury and reduced electrolyte leakage percentage and malondialdehyde accumulation. Exogenous application of H2S and PA maintained significantly higher levels of proline, total phenols, and flavonoids. It was also found that H2S and PA reduced the hydrogen peroxide accumulation with up-regulated activities of superoxide dismutase, catalase, and ascorbate peroxidase. These results indicated that H2S and PA alleviated chilling injury of eggplant fruit may through the enhancement of reactive oxygen species scavenging system activity, proline, and phenolic accumulation. Practical applications Eggplant fruits are a good source of anthocyanin, phenolic compounds, and vitamins. Low temperature storage is effective for preserving nutritional quality during storage time, however, eggplant fruits are chilling sensitive. We investigated the effect of hydrogen sulfide (H2S) and phenylalanine (PA) to alleviate chilling injury in eggplant fruits during cold storage. H2S and PA treatments ameliorated chilling injury in eggplant fruit with decreasing electrolyte leakage percentage and malondialdehyde accumulation. Eggplant fruit treated with H2S and PA exhibited higher 2, 2,-diphenyl-2-picryl-hydrazyl-scavenging capacity resulting from enhancing enzymatic antioxidant activities and increasing proline and phenolic compound accumulation.

Effect of improved land and water management strategies on crop productivity and soil fertility in wastewater irrigated eggplant (Solanum melongena)

Wastewater irrigation with efficient land and water management strategies improve the marketable yield as well as reduce the pollutant threat posed by the irrigation. A field experiment was conducted for two years (2014- 2016) at ICAR- IARI farm, New Delhi to study the effect of municipal wastewater irrigation along with two land configurations (ridge and furrow and basin) and two methods of irrigation (drip and flood) on the yield of eggplant (Solanum melongena cv. Supriya) and soil health. Wastewater irrigated eggplants resulted significantly higher yield (37.1 t/ha), fruit weight (325 g) and fruit diameter (10.02 cm) in the tune of 38, 26 and 7% higher respectively over groundwater irrigated plot. Among irrigation methods, drip irrigation increased yield, fruit weight and fruit diameter of eggplant by 10, 9 and 1% higher over flood irrigation. Significantly higher fruit weight (294 g) of eggplant was recorded with the flat bed system compared to a raised bed system (288 g) and higher yield (4%) was also recorded under a flat bed system over a raised bed system. Wastewater irrigated plots recorded higher plant height, number of branches per plant as compared to groundwater irrigated plants at 120 and 180 days after transplanting. Application of wastewater significantly enhanced available N and P content and DTPA-Pb and Fe in the soil as compared to groundwater irrigated soil. Flood irrigation led to the accumulation of DTPA-Pb and Ni in soil, compared to drip irrigation. Significantly higher dehydrogenase activity, fluorescein diacetate activity and soil microbial biomass carbon were noticed in wastewater irrigated soil as compared to groundwater plots at upper depth (0-5cm). The findings of the present investigation illustrate that wastewater applied through drip irrigation resulted in yield increment as well as reduced metal concentrations in soil.

Fitness cost but no selection for virulence in Meloidogyne incognita after two consecutive crops of eggplant grafted onto Solanum torvum

The eggplant Solanum melongena cv. Cristal, either ungrafted or grafted onto the Solanum torvum rootstock cv. Brutus, was cultivated for two consecutive years in the same plots in a plastic greenhouse to assess the level of resistance to Meloidogyne incognita and crop yield. At the end of the second crop, the putative selection for virulence of the nematode subpopulations coming from infected ungrafted and grafted eggplant was assessed in the eggplant and in S. torvum in a pot experiment. Nematode population densities at transplantation in 2017 ranged from 2 to 378 per 100 cm3 of soil and did not differ between ungrafted and grafted eggplant. At the end of each crop, a higher galling index and number of nematodes in soil and in roots was registered in ungrafted compared to grafted eggplant. The grafted eggplant was categorized as resistant in 2017 and as highly resistant in 2018. Eggplant yield did not differ irrespective of grafting in 2017 after being cultivated for 135 days, but it differed after 251 days of cultivation in 2018. In the pot experiment, S. torvum was categorized as resistant to both M. incognita subpopulations. However, the M. incognita subpopulation obtained from roots of S. torvum produced 49.4% fewer egg masses and 56% fewer eggs per plant in the eggplant than the nematode subpopulation obtained from roots of the eggplant cv. Cristal. The results of this study revealed that the infective and reproductive fitness of the nematode decreased without having been selected for virulence.

Meloidogyne arenaria attacking eggplant in Souss region, Morocco

Root-knot nematodes extracted from eggplant (Solanum melongena cv. Black beauty) root samples collected from plantations in the Souss region of Morocco, was identified as Meloidogyne arenaria based on female perineal pattern and sequence-characterized amplified region polymerase chain reaction (SCAR-PCR) technique.

Pesticidal activity of Solanum elaeagnifolium Cav. Leaves against nematodes and perennial weeds

Sliver nightshade (Solanum elaeagnifolium Cav.) an invasive weed species in cultivated lands of Egypt threatens native and crop species. The allelopathic potential of this weed was assessed against nematode and weeds. The aqueous extracts of Sliver nightshade leaves and seeds exhibited strong impacts in root knot nematode Meloidogyne incognita galls, egg-masses, female's numbers and juveniles' number. The incorporate dried leaves of S. elaeagnifolium with soil positively affected M. incognita infection and enhanced Eggplant Solanum melongena cv. white Balady growth traits under the greenhouse proportional to concentration. The allelopathy of aqueous extracts negatively influenced Convolvulus arvensis, Polypogon monspeliensis, Phalaris minor and Triticum aestivum germination and growth. Bioassay and spectroscopic instruments guided to four active flavonoids; hydroxyl −3-methoxyflavone, quercetin, kaempferol 3β-D-(6”-O-cis-cinnamoyl glucoside) and chlorogenic acid on Convolvulus arvensis and Arabidopsis thaliana weeds total biomass. These findings proved the importance of invasive weeds allelochemicals to be considered as a source of natural pesticides into agricultural systems.

Effect of application frequency of naphthalene acetic acid on physiomorphological characters and yield of brinjal

A field experiment on brinjal (Solanum melongena cv of brinjal) was conducted at the research field of Regional Horticulture Research Station, Shibpur, Narsingdi during the rabi season of 2016-2017 to find out the suitable application frequency of Napthalene acetic acid (NAA) for higher and profitable yield of brinjal. Napthalene acetic acid (NAA) 40 ppm were sprayed at the different days interval after transplanting (DAT) and flowering initial stage (FIS) of brinjal. Distilled water spray (control) (T0) and five treatments of NAA applications were spraying at 15 DAT (T1), spraying at 15 DAT and at 1st FIS (T2), spraying at 15 DAT then thrice spray at 15 days interval starting from 1st FIS (T3), one spray before 7 days of first flower initiation and thrice spray at 7 days interval starting from1st flower initiation stage (T4) and one spray before 15 days of first flower initiation and thrice spray at 15 days interval starting from 1st flower initiation stage (T5). The NAA application frequencies had no significant effect on plant height, number of leaves/plant, leaf area/plant and specific leaf weight. The T2 and T4 treatments showed identical performances in respect of all parameters and T2 treatment gave maximum total dry matter/plant, long and medium styled flower percent, fruit set percent, number of fruits/plan and fruit yield per hectare.Res. Agric., Livest. Fish.5(2): 151-155, August 2018

First Report of Gilbertella persicaria Causing Soft Rot in Eggplant Fruit in Brazil

In March 2017, two eggplant fruit (Solanum melongena cv. Cica) were collected from field production in Cha-Grande, in the state of Pernambuco, Brazil, with circular, light brown and slightly sunken lesions in the apex, extending to the entire fruit in 3 to 4 days and developing a soft rot with abundant mycelial and sporangia production on the surface. After microscopic examination, a fungus belonging to the genus Gilbertella was identified. The fungus was isolated from soft rot observed in the fruit and pure cultures were obtained by transferring a single spore to potato dextrose agar (PDA). Two isolates were obtained and deposited in the culture collection “Micoteca URM Profa. Maria Auxiliadora Cavalcanti” at the Universidade Federal de Pernambuco (Recife, Brazil), as URM7670 and URM7671. Morphological characteristics include spherical, single sporangia with 57.2 to 96.2 µm diameter, yellow-brown to brown when young turning dark brown or black on maturity, and sporangia split longitudinally into two halves to release the spore and expose a columella obvoid, 23.4 to 65 × 26 to 52 µm. The sporangiospores were mostly globose to ellipsoid, smooth, hyaline, aseptate, and 7.8 to 13 × 5.2 to 10.4 µm. The morphological characteristics evaluated corroborate previously published data for Gilbertella persicaria (Benny 1991). The partial sequences of the internal transcribed spacer (ITS) and 28S (LSU) of the rDNA were obtained for the two isolates and deposited in GenBank (accession nos. MF804516, MF804517, MG573061, and MG573062, respectively). The isolates showed a 99% similarity with ITS and LSU sequences of the type strain G. persicaria CBS 190.32 (NR111692 and JN939197, respectively) according to BLAST search. A combined phylogenetic tree obtained by Bayesian method grouped the isolates with the G. persicaria clade with 100% of posterior probability, confirming the identification. Koch’s postulates were conducted by inoculating five asymptomatic eggplant fruit (cv. Cica) previously disinfested with 0.5% hypochlorite and unwounded or superficially wounded with a sterile needle at two equidistant points. Ten milliliters of a sporangiospore suspension (1 × 10⁵ sporangiospores/ml) obtained from a representative isolate (URM7670) were sprayed on the inoculation sites. Sterile distilled water was used as control. The inoculated fruits were maintained in plastic boxes that contained a portion of moistened cotton wool and were maintained in a moist chamber at ∼25°C for 5 days. Wounded inoculated fruit showed the first symptoms (circular, light brown spots) 48 h after inoculation and evolved into soft rot after 5 days. Hyaline hyphae and light brown to dark sporangia were observed over the surface of the infected fruit. The pathogen was reisolated, fulfilling Koch’s postulates. The control and unwounded fruit remained asymptomatic. This species is usually found in soils and dung, but has already been reported to cause rot in peach fruit (Ginting et al. 1996), dragon fruit (Guo et al. 2012), black plum (Pinho et al. 2014), and papaya (Cruz-Lachica et al. 2016). To our knowledge, G. persicaria represents a new report in the world associated with soft rot in eggplant. This work will certainly contribute to the knowledge of pathogens that affect eggplant culture and, consequently, future studies that involve disease management strategies.

Assessing the Pathogenic Ability of Ralstonia pseudosolanacearum (Ralstonia solanacearum Phylotype I) from Ornamental Rosa spp. Plants.

Ralstonia pseudosolanacearum (Ralstonia solanacearum phylotype I) isolates found in stunted, yellowing, and wilted ornamental rose (Rosa spp.) were assessed for their pathogenic ability in two rose cultivars (cv. “Armando” and cv. “Red Naomi”) and in four solanaceous crops: tomato (Solanum lycopersicum cv. “Money Maker”), tobacco (Nicotiana tabacum cv. “White Burley”), eggplant (Solanum melongena cv. “Black Beauty”) and sweet pepper (Capsicum annum cv. “Yolo Wonder”). Significant differences were observed in susceptibility between the two rose cultivars as well as between the two modes of inoculation performed. The cultivar “Armando” was significantly more susceptible than cultivar “Red Naomi,” exhibiting higher disease severity and incidence. Similarly, stem inoculation after wounding was found to be significantly more effective than soil drenching, resulting in higher disease severity. Additionally, a temperature dependency in susceptibility was observed for both cultivars irrespective of the mode of inoculation, however, this was significantly more pronounced upon soil drenching. The solanaceous crops all showed to be susceptible to the R. pseudosolanacearum isolates originated from the Rosa spp. plants. Furthermore, both rose cultivars were able to harbor symptomless infections with other R. pseudosolanacearum and R. solanacearum isolates than those isolated from rose. Our results clearly demonstrated that latent infections in a rose cultivar such as cv. “Red Naomi” do occur even at temperatures as low as 20°C. This latency poses high risks for the entire floricultural industry as latently infected Rosa spp. plants are propagated and distributed over various continents, including areas where climatic conditions are optimal for the pathogen.

Influence of Root Exudates and Soil on Attachment of Pasteuria penetrans to Meloidogyne arenaria

The bacterium Pasteuria penetrans is a parasite of root-knot nematodes (Meloidogyne spp.). Endospores of P. penetrans attach to the cuticle of second-stage juveniles (J2) and subsequently sterilize infected females. When encumbered by large numbers of spores, juveniles are less mobile and their ability to infect roots is reduced. This study looked at different factors that influence spore attachment of P. penetrans to the root-knot nematode Meloidogyne arenaria. Pretreatment of J2 with root exudates of eggplant (Solanum melongena cv. Black beauty) reduced spore attachment compared with pretreatment with phosphate-buffered saline (PBS), suggesting that the nematode surface coat was altered or the spore recognition domains on the nematode surface were blocked. Spore attachment was equally reduced following exposure to root exudates from both host and nonhost plants for M. arenaria, indicating a common signal that affects spore attachment. Although phytohormones have been shown to influence the lipophilicity of the nematode surface coat, auxins and kinetins did not affect spore attachment compared with PBS. Root exudates reduced spore attachment more in sterilized soil than in natural soil. Sterilization may have eliminated microbes that consume root exudates, or altered the chemical components of the soil solution or root exudates. Root exudates caused a greater decrease in spore attachment in loamy sand than in a sandy loam soil. The sandy loam had higher clay content than the loamy sand, which may have resulted in more adsorption of compounds in the root exudates that affect spore attachment. The components of the root exudates could have also been modified by soil type. The results of this study demonstrate that root exudates can decrease the attachment of P. penetrans endospores to root-knot nematodes, indicating that when these nematodes enter the root zone their susceptibility to spore attachment may decrease.

Green Nanoparticles Engineering on Root-knot Nematode Infecting Eggplants and Their Effect on Plant DNA Modification.

Background Root-knot nematodes are known to cause significant damage to eggplants. New approaches by green silver nanoparticles (GSN) are used to control plant-parasitic nematode to avoid chemical nematicide hazards. Objectives Analyses of the incorporation of different concentrations of nanoparticles on two different algae (Ulva lactuca and Turbinaria turbinata) were carried out. Furethermore, the effect of GSN on the eggplant DNA profile was studied using RAPD and EST molecular markers. Materials and Methods Green Silver Nanoparticles (GSN) have been synthesized and characterized using the algal extract solution prepared from two algal genera. Nematicidal effect of the GSN was evaluated in greenhouse on eggplants (Solanum melongena cv. Login). Genomic DNA was extracted for use in molecular analysis. Both RAPD and EST molecular markers were used to study the GSN effect on eggplant DNA modification. Results GSN (17 mg.mL-1) obtained from U. lactuca was more effective in reducing second-stage juveniles (J2s) of M. javanica (69.44%) population in soil. All treatments improved eggplants growth parameters. Change in DNA profile using of both RAPD and EST markers was noted. Conclusions GSN (12.75 mg.100 mL-1) were effective on controlling the root-knot nematode (both T. turbinata and U. lactuca algae), similar to chemical control in eggplants. GSN did not cause any phototoxicity in eggplants under treatment.

Agronomical Performance of High Yielding Cultivar of Eggplant (Solanum melongena L.) Grown in Sewage Sludge Amended Soil

<p><em>A field study was conducted to assess the agronomical performance of eggplant (</em><em>Solanum melongena</em><em> cv. Pusa Purple Long Hybrid-F<sub>1</sub>) grown in sewage sludge amended soil in rainy and summer seasons during two consecutive years 2012 and 2013.</em><em> The results </em><em>showed that sewage sludge significantly (P</em><em> </em><em><</em><em> </em><em>0.05/P</em><em> </em><em><</em><em> </em><em>0.01) increased the </em><em>O</em><em>rganic </em><em>C</em><em>arbon (OC), sodium (Na<sup>+</sup>), potassium (K<sup>+</sup>), calcium (Ca<sup>2+</sup>), magnesium (Mg<sup>2+</sup>), </em><em>T</em><em>otal Kjeldahl </em><em>N</em><em>itrogen (TKN), phosphate (PO<sub>4</sub><sup>3-</sup>), sulphate (SO<sub>4</sub><sup>2-</sup>), cadmium (Cd), chromium (Cr), copper (Cu), manganese (Mn) and zinc (Zn) in the soil. </em><em>The contents of metals were found below the harmful levels prescribed for soils in India. </em><em>The maximum agronomic performance in the form of plant height, root length, dry weight, chlorophyll content, </em><em>L</em><em>eaf </em><em>A</em><em>rea </em><em>I</em><em>ndex (LAI), yield/plant and biochemical components like total carbohydrate, crude protein and dietary fiber of S. melongena</em><em> </em><em>were observed at 50% concentration of sewage sludge in both seasons. The contents of Cd, Cr, Cu, Mn and Zn in S. melongena</em><em> </em><em>were increased from 5% to 100% treatments of sewage sludge in both seasons. The order of </em><em>C</em><em>ontamination factor (Cf) of different heavy metals was Mn</em><em> </em><em>></em><em> </em><em>Cr</em><em> </em><em>></em><em> </em><em>Cd</em><em> </em><em>></em><em> </em><em>Zn</em><em> </em><em>></em><em> </em><em>Cu for soil and Cr</em><em> </em><em>></em><em> </em><em>Cd</em><em> </em><em>></em><em> </em><em>Cu</em><em> </em><em>></em><em> </em><em>Mn</em><em> </em><em>></em><em> </em><em>Zn for S. melongena</em><em> </em><em>plants after treatment of sewage sludge. Thus, use of sewage sludge increased concentration of heavy metals in soil and S. melongena. Hence, sewage sludge can be governed as organic fertilizer in lower proportion to avoid the contamination of soil and S. melongena.</em></p>

Investigation of the ameliorating effects of eggplant, datura, orange nightshade, local Iranian tobacco, and field tomato as rootstocks on alkali stress in tomato plants

Among the most important quality parameters of irrigation water used for greenhouse crops, alkalinity of water is considered critical due to its impact on soil or growing medium solution pH. In this study, plant growth, Fe content, photosynthetic pigment content, maximal quantum yield of PSII photochemistry (Fv/Fm), performance index (PI), leaf relative water content (LRWC), and soluble sugars concentration were investigated in nongrafted and grafted tomato (Lycopersicon esculentum Mill. cv. Red stone) plants onto five rootstocks of eggplant (Solanum melongena cv. Long purple), datura (Datura patula), orange nightshade (Solanum luteum Mill.), local Iranian tobacco (Nicotiana tabacum), and field tomato (Lycopersicon esculentum Mill. cv. Cal.jn3), exposed to 0, 5, and 10 mM NaHCO3 concentrations, to determine whether grafting could improve alkalinity tolerance of tomato. Significant depression of leaf area, leaf and stem dry mass, shoot and root Fe content and LRWC under high NaHCO3 level was observed in both grafted and ungrafted plants. The highest reduction in the shoot Fe content was observed at 10 mM sodium bicarbonate in control plants (greenhouse tomato). Moreover, at high HCO3 - level, the highest percentage of LRWC reduction was also recorded in ungrafted plants. Values of Fv/Fm and PI decreased significantly at 5 and 10 mM NaHCO3 irrespective of rootstock type. The present study revealed that soluble sugars content, photosynthetic pigments content, Fv/Fm and PI values in plants grafted onto datura rootstock were higher than those in nongrafted and rest of the grafted plants. Thus, the use of datura rootstock could provide a useful tool to improve alkalinity tolerance of tomato plants under NaHCO3 stress.

Vegetative compatibility of cotton-defoliating Verticillium dahliae in Israel and its pathogenicity to various crop plants

Verticillium dahliae isolates recovered from a new focus of severe Verticillium wilt of cotton in the northeast of Israel were tested for vegetative compatibility using nitrate non-utilizing (nit) mutants and identified as VCG1, which is a new record in Israel. Other cotton isolates of V. dahliae from the northern and southern parts of the country were assigned to VCG2B and VCG4B, respectively. VCG1 isolates induced severe leaf symptoms, stunting and defoliation of cotton cv. Acala SJ-2, and thus were characterized as the cotton-defoliating (D) pathotype, whereas isolates of VCG2B and VCG4B were confirmed as the earlier described defoliating-like (DL) and non-defoliating (ND) pathotypes, respectively. This is the first record of the D-pathotype in Israel. The host range of representative isolates of each VCG-associated pathotype was investigated using a number of cultivated plants. Overall, the D isolates were more virulent than DL isolates on all tested host plants, but the order of hosts (from highly susceptible to resistant) was the same: okra (Hibiscus esculentus local cultivar), cotton (Gossypium hirsutum cv. Acala SJ2), watermelon (Citrullus lanatus cv. Crimson Sweet), safflower (Carthamus tinctorius cv. PI 251264), sunflower (Helianthus annuum cv. 2053), eggplant (Solanum melongena cv. Black Beauty), and tomato (Lycopersicon esculentum cv. Rehovot 13). The pattern of virulence of ND isolates differed from that of D and DL isolates, so that the former were highly virulent on eggplant but mildly virulent on cotton. Tomato was resistant to all cotton V. dahliae isolates tested. RAPD and specific PCR assays confirmed that the D isolates from Israel were similar to those originating from other countries.

Abstracts of Nippon Dojo-Hiryogaku Zasshi

Abstracts of Nippon Dojo-Hiryogaku Zasshi

Tomato Production in the Hot-wet Season using Grafting and Rainshelter Technology

Production of tomato (Lycopersicon esculentum) during the hot-wet season in the lowland humid tropics can be increased using grafted plants and rainshelter. This technology can reduce soil-borne diseases, improve the ability of tomato plants to tolerate high temperatures and flooding due to high rainfall, and protect the crop from the impact of heavy rains. AVRDC has developed tomato lines that are resistant to virus diseases and high temperatures. This experiment was conducted to evaluate the performance of these lines in the hot-wet season, with and without rainshelter protection. Tomato lines (CHT501, TLCV15, and FMTT847) were grafted onto eggplant (Solanum melongena cv. EG203) rootstock and grown under rainshelter and open field. Nongrafted plants of three lines were also grown under two rainshelter treatments. The experimental design was a split-plot with four replications. Plants were managed using AVRDC standard practices for summer tomato production. TLCV15 and FMTT847 were highly resistant to tomato leaf curl virus (ToLCV), whereas CHT501 was greatly infected by the virus disease. All nongrafted plants died from bacterial wilt, whereas grafted plants survived the disease and outyielded nongrafted plants by 233% in the open field and 143% under rainshelters. Plants under rainshelters had a slightly lower yield than in the open field, but the difference was nonsignificant. Due to lack of frequent high rainfall during the season, the benefit of rainshelter was not detected and realized. It was concluded that TLCV15 and FMTT847 are well suited for grafted tomato production during the hot-wet season.

Somatic hybrids between Solanum melongena and S. sisymbrifolium, as a useful source of resistance against bacterial and fungal wilts

By using electrofusion of mesophyll protoplasts, 4 clones of somatic hybrids were produced between Solanum melongena cv. Pusa purple cluster and Solanum sisymbrifolium, a sexually incompatible wild relative resistant to bacterial ( Ralstonia solanacearum) and fungal ( Verticillium dahliae) wilts. All hybrids were morphologically homogeneous, normal and intermediate between the parents. They set flowers and produced fruits with empty seeds. Their hybrid status was confirmed by examining isoenzymes and random amplified polymorphism DNA analysis. Chloroplast-specific-cleaved amplified polymorphism sequence markers provided evidence that the 4 somatic hybrids possessed chloroplast genome from S. sisymbrifolium. Flow cytometry and chromosome countings revealed that all selected hybrids were tetraploids (2n=4x=48 chromosomes). The parental origin of the hybrid chromosomes was determined by using the techniques of genomic in situ hybridisation. Each hybrid contained one complete set of chromosomes from both parents. Neither spatial separation and recombinant chromosomes nor translocation could be demonstrated during mitotic metaphase. In vitro tests for resistance, using suspensions of two strains of R. solanacearum (race 1 and race 3) and the filtrate of culture medium of one strain of V. dahliae revealed that S. melongena was highly susceptible, whereas S. sisymbrifolium had variable levels of resistance. All somatic hybrids tested showed good levels of resistance, intermediate between those of the parents.

Phosphorus Metabolism and Yield Response to Increases in Nitrogen−Phosphorus Fertilization: Improvement in Greenhouse Cultivation of Eggplant (Solanum melongenaCv. Bonica)

The effect that application of nitrogen−phosphorus (NP) rates exerts on some parameters of phosphorus metabolism in eggplant (Solanum melongena cv. Bonica) was studied. All plants were grown under controlled conditions in an experimental greenhouse. The treatments consisted of the combination of three rates of N in the form of KNO3 (N1 = 15 g m-2; N2 = 22.5 g m-2; and N3 = 30 g m-2) together with two rates of P in the form of H3PO4 (P1 = 24 g m-2 and P2 = 36 g m-2), for a total of six treatments. The results obtained show a positive effect of NP fertilization on the nutritional status of P in the plants, clearly reflected in the response of bioindicators of the P (acid phosphatase activity and carbohydrates). The plants treated with N3P2 registered greater integration or assimilation of inorganic P to organic P, a fact that may be related to the maximum total and commercial yield in these plants and minimum noncommercial yield. Keywords: Solanum melongena L.; NP fertilization; phosphorus metabolism; bioindicators

Nitrogen Metabolism and Yield Response to Increases in Nitrogen−Phosphorus Fertilization: Improvement in Greenhouse Cultivation of Eggplant (Solanum melongena Cv. Bonica)

The effect that application of nitrogen−phosphorus (NP) rates exerts on some parameters of nitrogen metabolism and on yield in aubergine plants (eggplant, Solanum melongena cv. Bonica) was studied. All plants were grown under controlled conditions in an experimental greenhouse. The treatments consisted of the combination of three rates of N in the form of KNO3 (N1: 15 g m-2, N2: 22.5 g m,-2 and N3: 30 g m-2) together with two rates of P in the form of H3PO4 (P1: 24 g m-2 and P2: 36 g m-2), for a total of six treatments. Results indicate that regardless of the P rate applied, an increase in the N fertilizer increased NO3- assimilation as well as total and commercial yield. Use of the P2 rate favored all of these processes in comparison with the results obtained with the P1 rate, in addition to notably reducing the foliar levels of NO3- and noncommercial yield. Keywords: Solanum melongena L.; NP fertilization; nitrogen assimilation; yield