Arka Vikas Research Articles

Genetic Variation for Tolerance to High Temperatures in Tomato Using Critical Sterility Temperature

Tomato (Solanum lycopersicum L.) reproduction is influenced by temperature, prominently impacting yield. The ideal daytime range is between 25°C and 30°C and the nighttime temperature is around 20°C for tomato and deviations of a few degrees from these temperatures can have negative effects. The study assessed the effect of temperature on tomato pollen germination and aimed to ascertain the critical sterility temperature for pollen germination. In an open field, pollen from 10 genotypes (Anagha, Manuprabha, Vellayani Vijay, Akshaya, Nandi, IIHR26372, Pusa Rohini, Arka Saurabh, Arka Rakshak, and Arka Vikas) underwent In-vitro temperature exposure ranging from 32 to 40°C at 2°C intervals. Variations in In-vitro pollen germination percentage were observed across the genotypes, notably revealing a sharp decline after 36°C. This decline indicated a pivotal shift in pollen germination and viability. Genotypes, Anagha and Arka Saurabh, were identified as temperature tolerant and susceptible, respectively. The findings present an opportunity to incorporate temperature-dependent pollen response functions and identified genotypes into tomato breeding programs, offering significant implications for enhancing yield under varying temperature conditions.

Screening of Tomato (Solanum lycopersicum) Germplasm against Fusarium Wilt and Tomato Leaf Curl Virus Diseases in Naturally Ventilated Polyhouse

Aims: Screening of tomato germplasm against fusarium wilt and tomato leaf curl virus diseases in naturally ventilated polyhouse. Place and Duration of Study: The experiment was conducted during rabi 2020-2021 under naturally ventilated poly house, which located at Center of Excellence, Dr. Y.S.R. Horticultural University, Venkataramannnagudem. Methodology: Total 21 tomato genotypes which included 18 germplasm lines and 3 commercial cultivars as a check (Arkavikas, Polyana and BSS 1006) collected from the HRS, Venkataramannagudem which were screened against major diseases of tomato under naturally ventilated polyhouse and to find out resistance source. Results: Among the 21 genotypes screened against tomato leaf curl virus lowest per cent disease incidence was recorded in VRSL (Venkataramannagudem Solanum lycopersicum) -114 (5.88 %), VRSL-134 (6.54 %) and VRSL-136 (6.86 %). Highest per cent disease incidence was recorded in Arka vikas (17.87 %). Among the 21 genotypes screened lowest per cent disease incidence was recorded in VRSL -40 and VRSL-134 (9.79 %). Highest per cent disease incidence was recorded in A.vikas (32.28 %).

Tomato and Brinjal Germplasm Screening and Rootstock Identification for Fusarium Wilt Resistance

Fusarium oxysporum is a destructive disease of tomato (Solanum lycopersicum L.) that causes large yield losses in fields and commercial greenhouses, implying the need for disease resistance research. The current study was conducted in Rabi - 2021 at the Postgraduate Research Block, Department of Vegetable Science, College of Horticulture, Sri Konda Laxman Telangana State Horticultural University, Rajendranagar, Hyderabad. In the present study, 25 genotypes of tomato and brinjal were studied for Fusarium wilt resistance at morphological level. Scoring of Fusarium wilt infection severity based on morphological symptoms revealed five groups viz., asymptomatic/no chlorosis in one cultivar (Solanum torvum) slight chlorosis of leaves in two genotypes (Arka Keshav and Surya), Moderate chlorosis with wilting or stunting of the plant in ten genotypes (EC-620509, EC-615055, EC-620378, EC-620389, EC-620394, EC-620422, EC-631369, AVTO-9803, EC-620428 and EC-631379), severe chlorosis with wilting and stunting of the plant in four genotypes (EC-620503, LA-1589, Marutham and PKM-1) and plant death was observed in eight genotypes (EC-620441, EC-620452, LA -0490, Money maker, Pusa rohini, Pusa sheethal, including susceptible checks (Pusa Ruby and Arka Vikas). Genotypes exhibiting Fusarium wilt resistance will be grafted on to commercial variety of tomato and evaluated under open field conditions for yield, quality parameters and disease resistance under Telangana conditions.

Evaluation of Growth and Pollen Viability (Fertility) in Relation to Fruit Set among Five Varieties of Tomato

The evaluation of pollen viability and fruit setting capacity are two essential criteria for pollinator’s characterization. This study was carried out to evaluate pollen Fertility/ viability in five Varieties of Tomatoes. We analyzed the viability of pollen grains of five different varieties of tomatoes grown in ITM University, Gwalior, Madhya Pradesh, India. Aceto- carmine method is used to estimate pollen viability. The germination percentage, pollen viability and Fruit setting rate were recorded at different stages respectively. Pollen viability in relation to fruit set was analyzed while growth parameters and fruit yield per plant of each variety were also collected and analyzed. Results displayed that the highest pollen viability rate (100%) was obtained in SWEAKAR-448 Variety followed by Arka Vikas (95%), ARJUN-135 (93%), 9005-SIRI (90%) and PKM-1 (80%). The highest percentage of germination (95%) was shown by 9005-SIRI Variety and maximum fruit setting (15-20 Fruits per plant) was recorded in the SWEAKAR-448 Variety. The results showed significant vegetative growth variations and correlations between pollen viability and fruit setting characters. In addition, it was found a noticeable variation in Pollen viability/fertility, was not proportional to fruit setting percentage. In general Pollen viability was directly linked to fruit set, whereas formation and fruit set were not in the tomato varieties that were investigated. Pollen viability was high, which was accompanied through a reduction in the number of fruit sets, fruit size and pollen viability in the field is highly variable, indicating that differences in microenvironment may have a profound effect on fruit setting and pollen viability.

Screening of tomato (Solanum lycopersicon L.) genotypes by inducing systemic resistance against early blight disease caused by Alternaria solani

Early blight of tomato (Solanum lycopersicon L.) incited by Alternaria solani is highly destructive disease in the world. Environmental factors significantly impact early blight epidemics, leading to the loss of up to 78 per cent of tomato production. Twenty tomato genotypes were used in this study to identify the early blight resistant and susceptible genotypes selected to represent a range of reactions when screened under field conditions. The tomato plants were evaluated for early blight disease by using Per cent Disease Index (PDI). Pusa Uphar (20.18%) and Sankaranti (20.18%) showed resistance to early blight disease among the twenty genotypes. Anaka Kerala (61.25%), Arka Vikas (61.76%), Pusa Rohini (53.65%), Ashoka (50.60%) and Paiyur1 (56.08%) genotypes were found highly susceptible based on early blight disease intensity. Spore inoculation of A. solani was sprayed into tomato plants, it was discovered that the number of defense-inducing compounds viz., total phenols, peroxidase (PO), polyphenol oxidase (PPO) and phenylalanine ammonia lyase (PAL) has increased. Among the genotypes, Pusa Uphar (T2) and Sankaranti (T1) genotypes showed a high level of defense enzyme production. After tomato plants were exposed to pathogens through artificial inoculation, the activity of these defensive enzymes and compounds was highly induced in the resistant and sensitive germplasm than in the control.

Relative bioefficacy of different insecticides against sucking pest complex of tomato (Lycopersicum esculentum L.) and their effect on natural enemies present under field condition

The field experiment was carried out on tomato in the Rabi season of 2019-20 at the Vegetable Research Farm, Institute of Agricultural Science, Banaras Hindu University, Varanasi, India. The crop variety, Arka Vikas (Selection 22) was selected to evaluate the bioefficacy of nine different insecticidal treatments against the sucking pest complex and the natural enemies in tomato under field conditions. Two sprays at 15 days intervals of ten treatments with three replications were applied. The treatments were Diafenthiuron 50% WP, Abamectin 1.8% EC, Buprofezin 25% SC, Indoxacarb 14.5% SC, Spinosad 45% SC, Chlorantraniliprole 18.5% SC, Pymetrozine 50% WG, Flonicamid 50% WG, and Lancer Gold (50 + 1.8) % SP and control (water spray). Observations were recorded one day before and 1st, 3rd, 5th, 7th, 10th, and 15th days after each spray. For controlling Whitefly (B. tabaci), Lancer gold was observed to be the best (76.98%), followed by Pymetrozine (69.03%) and Flonicamid (59.39%). At the same time, Flonicamid was excellent (70.62%) in controlling Aphids (A. gossypii), followed by Lancer gold (67.15%) and Pymetrozine (65.48%). In case of a reduction of damage by Thrips (T. tabaci), Lancer gold showed the best result (75.60%), followed by Buprofezin (68.45%) and Flonicamid (65.69%). However, all the treatments showed minute toxicity for the natural enemies; yet Flonicamid and Lancer gold were significantly safer among all of them.

STUDIES ON INHERITANCE OF BACTERIAL WILT RESISTANCE IN TOMATO CROP CAUSED BY Ralstonia solanacearum (E.F. SMITH)

The study aimed at the inheritance of bacterial wilt resistance in tomato with six different generations (P1, P2, F1, F2, BC1 and BC2) obtained by 4 crosses (Susceptible X Resistant). Two susceptible cultivars (Arka Meghali and Arka Vikas) and two resistant lines (H-7996 and H-7997) of tomato were crossed during kharif , 2020 in four possible combinations to generate the experimental material. The P1, P2, F1, F2 BC1 and BC2 generations of 4 crosses were screened for bacterial wilt caused by Ralstonia solanacearum (E.F. Smith) in tomato research fields of Monsanto Holdings Private Ltd., Kallinayakana Halli village, Gauribidanuru Taluka, Chikkaballapura District, Karnataka to understand the mode of inheritance. Single dominant gene controlling the resistance to bacterial wilt was observed in two crosses between Arka Meghali x H-7996 and Arka Vikas x H- 7997. Chi-square test for goodness of fit indicated that the F2 is segregating in the ratio 3 resistant to 1 susceptible in the single gene model. Resistant to susceptible ratio in BC2 was 1:1. While, in the crosses between Arka Vikas x H-7996 and Arka Meghali x H-7997 the complimentary gene interaction was observed with the F2 expected ratio of 9:7 indicating duplicate recessive epistasis.

Effect of foliar-applied Euphorbia hirta towards controlling bacterial diseases in tomato crops and enhancing fruit yield and shelf life

ABSTRACT Bacterial diseases are a major cause of yield loss in tomato plants worldwide, and there is a need to identify strategies for control of these diseases. Bacterial wilt caused by Ralstonia solanacearum (RS) and bacterial spot caused by Xanthomonas axonopodis pv vesicatoria (Xav) are amongst the bacterial diseases affecting tomato crops. The current study investigates Euphorbia hirta (E. hirta) methanol extract (EHM) for its antibacterial activity against RS, and Xav induced diseases in tomato plants, along with its biostimulant potential in increasing fruit yield. EHM at 1280 mg/L exhibited 90% inhibition in the growth of both RS and Xav bacteria. Further, evaluation of EHM on Arka Vikas, a susceptible tomato variety, showed that pre-treatment of 15 days and 45 days tomato plants with 1280 mg/L EHM exhibited moderate resistance to bacterial wilt and spot disease, respectively, with increased tomato yield and improved chlorophyll b levels compared to control plants. The effectiveness of EHM in increasing fruit yield was further confirmed using field evaluation on ‘Namdhari NS 538’ variety of tomato plants. A 3.5-fold increase in numbers and weight of tomato was observed with foliar application of EHM (1280 mg/L). A significant reduction in fruit spoilage along with an increase in mRNA level of ethylene receptor factor (ERF1) was also observed. The study is the first to demonstrate the cost-effective and eco-friendly antibacterial and biostimulant potential of EHM (1280 mg/L) for tomato plants.

Reduced γ-glutamyl hydrolase activity likely contributes to high folate levels in Periyakulam-1 tomato.

Tomato cultivars show wide variation in nutraceutical folate in ripe fruits, yet the loci regulating folate levels in fruits remain unexplored. To decipher regulatory points, we compared two contrasting tomato cultivars: Periyakulam-1 (PKM-1) with high folate and Arka Vikas (AV) with low folate. The progression of ripening in PKM-1 was nearly similar to AV but had substantially lower ethylene emission. In parallel, the levels of phytohormones salicylic acid, ABA, and jasmonic acid were substantially lower than AV. The fruits of PKM-1 were metabolically distinct from AV, with upregulation of several amino acids. Consistent with higher °Brix, the red ripe fruits also showed upregulation of sugars and sugar-derived metabolites. In parallel with higher folate, PKM-1 fruits also had higher carotenoid levels, especially lycopene and β-carotene. The proteome analysis showed upregulation of carotenoid sequestration and folate metabolism-related proteins in PKM-1. The deglutamylation pathway mediated by γ-glutamyl hydrolase (GGH) was substantially reduced in PKM-1 at the red-ripe stage. The red-ripe fruits had reduced transcript levels of GGHs and lower GGH activity than AV. Conversely, the percent polyglutamylation of folate was much higher in PKM-1. Our analysis indicates the regulation of GGH activity as a potential target to elevate folate levels in tomato fruits.

Genetic variability, trait inter-relationships, third and fourth degree statistics based genetics for fruit quality and yield traits governing shelf life in tomato (Solanum lycopersicum L.)

AbstractKnowledge on genetic architecture and inheritance of tomato shelf life contributing traits in different genetic backgrounds is a key issue for shelf life improvement. An investigation was undertaken to estimate the nature and magnitude of variability, traits inter-relationships, third and fourth degree statistics to unravel the genetics of 18 fruit quality and yield traits governing shelflife in F2 population of ‘Arka Vikas’ × ‘Red ball’ cross. The wider standardized range and higher estimates of phenotypic coefficient of variation indicated prevalence of adequate variability for fruit quality and yield traits. Fruit firmness and pericarp thickness ranged from 1.20–3.44 kg/cm2 and 2.44–5.31 mm respectively. Pulp content and shelflife ranged from 58.59–94.70% and 10.60–26.40 days respectively. Significant positive correlation with direct effect on fruit shelf life was exhibited by fruit firmness, pericarp thickness, TSS, titratable acidity, pulp content, fruit length and locule number. Positive skewness with platykurtic distribution recorded for TSS, lycopene, ascorbic acid, titratable acidity, fruit length, weight, pericarp thickness, plant height and number of branches. Negatively skewed with platykurtic distribution observed for pH, fruit diameter, firmness, pulp content, locule number, shelf life and number of clusters which signified duplicate epistasis of dominant genes in traits inheritance. The transgressive segregants for fruit quality traits indicated complementary effects of dispersed allele combinations between parents. Additive and dominance components could be exploited in the advanced segregating population by evaluating large number of families. In addition to additive effects, predominance of dominance effects of genes are important in inheritance of fruit quality traits governing shelflife.

Heterosis and combining ability studies by line × tester analysis for fruit biochemical, morpho-physiological, and yield traits governing shelf life in tomato (Solanum lycopersicum L.)

Improving tomatoes keeping quality is crucial for reducing post-harvest losses. Knowledge of heterosis, and combining ability is a prerequisite for breeding high yielding and good shelf life heterotic hybrids. An investigation was undertaken with each of 3 lines, testers, and 9 hybrids to identify desirable parents and crosses for 20 fruit biochemical, morpho-physiological, and yield traits and to elucidate the nature of gene action for shelf life and its contributing traits through line × tester analysis. The lines contributed to most of hybrids variability than testers and fruit quality traits had a higher degree of SCA variance as compared to GCA variance. pH, ascorbic acid, fruit firmness, and plant height governed by additive gene action. Lycopene, titratable acidity, TSS, calcium, magnesium, pericarp thickness, pulp content, locule number, fruit length, diameter, weight, shelf life, number of branches, number of clusters, number of fruit/cluster, and yield/plant were under the control of non-additive gene action. All the lines and Arka Saurabh were the best general combiners and IIHR 2349 × Arka Vikas, IIHR 2349 × Arka Saurabh, IIHR 2358 × Arka Ahuti and IIHR 2357 × Arka Ahuti were the best specific combiner in producing heterotic hybrids. IIHR 2349 × Arka Vikas and IIHR 2349 × Arka Saurabh were promising hybrids for high yield and shelf life. The crosses involved both parents with high, one parent with high and other with low and both parents with low good overall general combining ability status respectively indicated the additive, non-additive and epistatic gene action in fruit quality and yield traits inheritance.

Highly efficient Agrobacterium-mediated transformation and plant regeneration system for genome engineering in tomato

Tomato (Solanum lycopersicum L.) is an important vegetable and nutritious crop plant worldwide. They are rich sources of several indispensable compounds such as lycopene, minerals, vitamins, carotenoids, essential amino acids, and bioactive polyphenols. Plant regeneration and Agrobacterium-mediated genetic transformation system from different explants in various genotypes of tomato are necessary for genetic improvement. Among diverse plant growth regulator (PGR) combinations and concentrations tested, Zeatin (ZEA) at 2.0 mg l−1 in combination with 0.1 mg l−1 indole-3-acetic acid (IAA) generated the most shoots/explant from the cotyledon of Arka Vikas (36.48 shoots/explant) and PED (24.68 shoots/explant), respectively. The hypocotyl explant produced 28.76 shoots/explant in Arka Vikas and 19.44 shoots/explant in PED. In contrast, leaf explant induced 23.54 shoots/explant in Arka Vikas and 17.64 shoots/explant in PED. The obtained multiple shoot buds from three explant types were elongated on a medium fortified with Gibberellic acid (GA3) (1.0 mg l−1), IAA (0.5 mg l−1), and ZEA (0.5 mg l−1) in both the cultivars. The rooting was observed on a medium amended with 0.5 mg l−1 indole 3-butyric acid (IBA). The transformation efficiency was significantly improved by optimizing the pre-culture of explants, co-cultivation duration, bacterial density and infection time, and acetosyringone concentration. The presence of transgenes in the plant genome was validated using different methods like histochemical GUS assay, Polymerase Chain Reaction (PCR), and Southern blotting. The transformation efficiency was 42.8% in PED and 64.6% in Arka Vikas. A highly repeatable plant regeneration protocol was established by manipulating various plant growth regulators (PGRs) in two tomato cultivars (Arka Vikas and PED). The Agrobacterium-mediated transformation method was optimized using different explants like cotyledon, hypocotyl, and leaf of two tomato genotypes. The present study could be favourable to transferring desirable traits and precise genome editing techniques to develop superior tomato genotypes.

SSR Marker Based Genetic Diversity and Fusarium Wilt Resistance Screening of Tomato (Solanum lycopersicum L.) Genotypes

Fusarium oxysporum is one of the devastating diseases of tomato (Solanum lycopersicum L.) causing high yield losses in fields and commercial greenhouses, inferring necessity for development of disease resistance. An research experiment was laid out with 23 diverse genotypes including susceptible check at research farm during wet season-2018 for screening of tomato genotypes for fusarium wilt resistance. Phenotypic screening of 23 genotypes revealed varied disease resistance as highly resistant (AVTO1219 and EC631), resistant (Pant bahar, EC620428, EC620378, EC631369 and EC620503), moderately resistant (EC615055, EC620389, EC620394, EC620422, EC620406 and AVTO9803) and moderately susceptible (PKM1, EC620382, EC620427 and EC620395) over the highly susceptible checks (Pusa Ruby, Arka Vikas). Employing 95 SSRs for molecular profiling resulted in 33 polymorphic markers, 58 monomorphic markers and remaining 4 markers as unamplified. A total of 74 alleles were detected using 33 polymorphic markers with an average allele number of 2.24 for each marker. Two markers viz., TES60 and TGS633 produced maximum (4) alleles. The polymorphic information content (PIC) value ranged from 0.28 to 0.76 with an average of 0.53 and marker TGS633 was found to be the most suitable marker with the highest PIC value. Cluster analysis through UPGMA method classified twenty three genotypes into five clusters and the coefficient among 23 genotypes was varied from 0.5 to 0.86. Over all, EC631379, EC631369, EC620428, EC620378 and EC620503 were identified as new resistant genetic resources against Fusarium wilt at both phenotypic and genotypic level with the presence of I-2 gene loci. Based on the results, the identified genotypes can be further tested and be used in Marker Assisted Selection or gene pyramiding programs to develop disease resistant commercial cultivars.

QUALITY ATTRIBUTES OF TOMATO GENOTYPES UNDER PROTECTED ENVIRONMENT

Tomatoes are an important part of a healthy human diet. The productivity and quality of the produce are being measured by using advanced production technologies. Protected cultivation is an advanced agrotechnology that is utilized all over the world to generate high quality output. Indeterminate tomato is a growing crop though, still, in Punjab, no systemic work has been done for the evaluation of quality attributes of indeterminate tomato genotypes under the protected environment. Inherent diversity is a chief concern for the improvement of quality attributes in tomato. Considering the importance of tomatoes, there is an urgent need to screen out genotypes of indeterminate tomato for a best quality production and for higher nutritive value. The investigation was carried out at the Department of Vegetable Science of Agriculture, Khalsa College, Amritsar, Punjab, India and the experiment were conducted under modified naturally ventilated polyhouse following Factorial Randomized Block Design with three replications, consisting twelve genotypes including standard check during spring-summer season, 2020-2021. The data exhibited significant variation in twelve genotypes for different characters. Based on mean performance, the result let out that Punjab Gaurav and JC-165 was superior for all the quality attributes. Whereas, pericarp thickness and fruit shape index were maximum in KCA-2 while Punjab Sartaj was sophisticated for TSS, lycopene and ascorbic acid although greater titrable acidity was recorded in Arka Vikas. Significantly, the result was higher due to the favorable conditions provided in a protected environment during the growing period with the interaction of genes of genotype.

Assessment of combining ability in tomato genotypes (Solanum lycopersicum L.) for quality traits

Combining ability effects (GCA and SCA) were estimated using seventeen parents including fourteen females and three males of tomato (Solanum lycopersicum L.) and their hybrids developed through line × tester method. The results indicated that the lines, HUB46 for fruit firmness and number of locules, HUB36 for fruit pH (-ve direction) and shelf life, HUB3 for equatorial diameter and TSS, HUB45 for pericarp thickness and polar diameter whereas, among testers Arka Vikas for fruit firmness, pericarp thickness, fruit pH (+ve direction), polar diameter exhibited significant gca effects and considered as good general combiners. Cross combinations HUB3×DMT-2 for fruit firmness and pericarp thickness, HUB10×DMT-2 for number of locules, HUB47× Arka Vikas for fruit pH (+ve direction), HUB14× Arka Vikas for TSS, shelf life and polar diameter, HUB4×PKM-1 for equatorial diameter exhibited significant positive sca effects and regarded as good specific combiners.

Studies on mode of gene action for fruit quality characteristics governing shelf life in tomato (Solanum lycopersicum L.)

Extending the shelf life of tomatoes is very essential for the reduction of great losses in quality and quantity. Knowledge of genetic architecture of the shelf life contributing traits and their inheritance pattern in different genetic backgrounds is a key issue for the development of high yielding and good shelf life cultivars. An investigation was undertaken to estimate the nature and magnitude of gene action for 18 fruit quality and yield traits governing shelf life through six generations (P1, P2, F1, F2, B1, and B2) mean analysis in the F1, Arka Vikas × Red ball cross. Inadequacy of additive-dominance model in explaining the inheritance of fruit quality traits governing shelf life revealed the significance of joint-scaling test and presence of epistasis. The dominance x dominance interaction was larger than the additive x additive and additive x dominance effects and the dominance component was greater than the additive component. Duplicate epistasis played a greater role than complementary epistasis. Shelf life and its contributing traits such as TSS, lycopene, titratable acidity, pH, ascorbic acid, fruit diameter, fruit firmness, locule number, and yield per plant are controlled by dominant genes with duplicate epistasis. Simple selection procedure in the early segregating generation for shelf life and its contributing traits is ineffective in improving genetic gain as dominance and dominance × dominance gene effects are non-fixable. The additive and dominance components successfully are exploited in the advanced segregating population by evaluating a large number of families. One to two cycles of bi-parental mating followed by intensive selection lead to dissipation of dominance and enhance the frequency of genes with increasing effects on the expression of fruit quality traits governing shelf life. Both additive and dominance with a predominance of dominance effects of genes are important in the inheritance of fruit quality traits governing shelf life.

XSP10 and SlSAMT, Fusarium wilt disease responsive genes of tomato (Solanum lycopersicum L.) express tissue specifically and interact with each other at cytoplasm in vivo.

The online version contains supplementary material available at 10.1007/s12298-021-01025-y.

Lycopene Content of Different Tomato Germplasms Grown under Irrigated and Water-stress Conditions

Lycopene content in raw tomato fruits of nine varieties is reported in plants grown under normal irrigation and water stress conditions. Lycopene was estimated on a fresh weight basis (FWB) by high-performance liquid chromatography. Under control conditions, the highest content was recorded in Pusa Rohini and Arka Vikas followed by EC179083, while the tomato germplasm with accession no. EC160885 ranked the lowest. Under stressed conditions, the lycopene content in all the germplasms increased. Maximum increase of 87.68 per cent was observed in EC179083 followed by Arka Vikas (65.43%). Pusa Rohini and Pusa Gaurav showed the lowest increase of 12–14 per cent. The results highlight the impact of water-stress on fruit nutrition quality and will help in selecting a variety/germplasm with high lycopene content under drought conditions.

SlHyPRP1 and DEA1, the multiple stress responsive eight-cysteine motif family genes of tomato (Solanum lycopersicum L.) are expressed tissue specifically, localize and interact at cytoplasm and plasma membrane in vivo.

Owing to rapid global climate change, the occurrence of multiple abiotic stresses is known to influence the outburst of biotic stress factors which affects crop productivity. Therefore, it is essential to understand the molecular and cell biology of key genes associated with multiple stress responses in crop plants. SlHyPRP1 and DEA1, the members of eight-cysteine motif (8CM) family genes have been recently identified as putative regulators of multiple stress responses in tomato (Solanum lycopersicum L.). In order to gain deeper insight into cell and molecular biology of SlHyPRP1 and DEA1, we performed their expression analysis in three tomato cultivars and in vivo cell biological analysis. The semi-quantitative PCR and qRT-PCR results showed the higher expression of SlHyPRP1 and DEA1 in leaf, stem, flower and root tissues as compared to fruit and seed tissues in all three cultivars. The expression levels of SlHyPRP1 and DEA1 were found to be relatively higher in a wilt susceptible tomato cultivar (Arka Vikas) than a multiple disease resistant cultivar (Arka Abhed). In vivo cell biological analysis through Gateway cloning and Bi-FC assay revealed the predominant sub-cellular localization and strong protein-protein interaction of SlHyPRP1 and DEA1 at the cytoplasm and plasma membrane. Moreover, SlHyPRP1 showed in vivo interaction with stress responsive proteins WRKY3 and MST1. Our findings suggest that SlHyPRP1 with DEA1 are co-expressed with tissue specificity and might function together by association with WRKY3 and MST1 in plasma membrane for regulating multiple stress responses in the tomato plant.

Phenotypic evaluation and utilization of tomato germplasm resistance for ToLCV and its vector Bemisia tabaci under natural condition

During May- June 2019, about 50 genotypes of tomato along with susceptible check, Arka Vikas were screened for resistance against the sweet potato whitefly, Bemisia tabaci and the begomovirus Tomato leaf curl virus (ToLCV) in a Randomized Block Design with two replications having a plot size of 5×4 m at Linga nayakan pati, Usilampatti Taluk, Madurai district. The population of whitefly was recorded on tomato at weekly interval from appearance of the whiteflies. The infestation found to be more at earlier weeks thereafter the population declined abruptly. The average minimum (0.24/plant) and maximum (3.41/plant) whitefly population during crop season was observed on EC-520078 andEC-165700. According to the mean of whitefly population the highest resistance was found in EC-520078 followed by EC-631364,EC-315477 and EC-620389. Among all the accessions observed for ToLCV resistance, the accession EC-520078 recorded only 7.88% disease incidence and found statistically significant as compared to other accessions while the maximum disease incidence was observed in EC-620372 (94.25%).