1. KAUTIR (Kerala Agricultural University Theses Information and Retrieval)
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Item Screening early segregating generation of brinjal (Solanum melongena L.) for resistance against shoot and fruit borer(Department of Plant Breeding and Genetics, College of Agriculture Vellanikkara, 2024-01-31) Ankit Kumar Upadhyay; Jiji JosephBrinjal, known as eggplant or guinea squash (Solanum melongena L.), belongs to the Solanaceae family. The fruit from the genus Solanum is also called “The King of vegetables”. It is an important solanaceous crop cultivated worldwide and is native to the Hindustan-China center, where it still grows in the wild. The brinjal crop is highly vulnerable to several pests and diseases. Among these, the production and productivity of the crop are severely affected by brinjal shoot and fruit borer (BSFB; Leucinodes orbonalis G.) reducing its market value. The loss caused by the pest may reach up to 70 - 92 per cent. The inadequacy of reliable biological control for the management of BSFB leaves farmers to resort to insecticides. This underscores the critical necessity for extensive research and the development of varieties resistant to shoot and fruit borer. Such resistant varieties have the potential to emerge as the most environment friendly, cost-effective, and sustainable method for pest control. In this context, the present study entitled “Screening early segregating generations of brinjal (Solanum melongena L.) for resistance against shoot and fruit borer” was conducted to investigate and select the superior lines with resistance to shoot and fruit borer from early segregating generations. Segregating generations of two crosses i.e., Ponni × Vengeri (F3 and F4 generations) and Ponni × IC624241 (F2 generation) were evaluated along with the parents and check varieties. Segregation with wide variation was observed in all the generations viz—F2, F3, and F4 of the respective crosses. Regarding fruit colour, both the segregating generations of Ponni (green) × Vengeri (purple-green) showed wide variation in the colouring pattern. The segregating generations had both oblong and long-shaped fruits similar to parental types i.e., Ponni (oblong) and Vengeri (long). Besides, elongated fruits were also observed in both generations. All the fruits in the F2 generation of Ponni × IC624241, exhibited green colour similar to the parent Ponni whereas, the fruit shape was round as in IC624241. Range, mean, variance, genotypic coefficient of variance (GCV) (%), phenotypic coefficient of variance (PCV) (%), heritability (H2), genetic advance (GA), genetic advance as percentage over mean (%) (GAM), skewness, kurtosis, and correlation between growth and yield traits were estimated in F2, F3, and F4 75 generations of the respective crosses. PCV was higher than GCV for all the traits in all the generations. The observed variability across all studied populations remained consistently high for various traits. This variability persisted in the subsequent generations, as indicated by the range, GCV, PCV, H2, GA, GAM, skewness, and kurtosis. This suggests that a single seed descent (SSD) method was employed throughout the generations without any selection process. For pedigree selection BSFB scoring according to Mishra et al., (1988) at the fruiting and shooting stage was performed and all the lines were categorized as susceptible to highly susceptible in accordance with their scale. The selection criteria for identifying the best-performing lines were based on percentage of fruit infestation, marketable yield, fruit yield per plant, and percentage of shoot infestation. Based on the selection criteria lines 1.2.18, 1.2.10, and 1.3.10 were identified from the F3 generation of the cross between Ponni × Vengeri and were forwarded as F4 lines. In the F2 generation of the cross between Ponni × IC624241, five F2 plants showed 50 per cent of fruit resistance but, due to susceptibility to bacterial wilt and low population size, further studies were not conducted. Correlation data from F3 (Ponni × Vengeri) and F2 (Ponni × IC624241) generation of the crosses revealed a positive association between the number of flowers, number of shoots, fruits per plant, and length of fruit with shoot and fruit infestation. However, in the F4 generation of Ponni × Vengeri the length and diameter of the fruit showed a negative correlation with the shoot and fruit infestation by BSFB. Fruit yield per plant was positively associated with the number of flowers, shoots, fruits, length of fruit, and average fruit weight in all the studied populations. The diameter of the fruit also showed a positive association with yield in the F2 (Ponni × IC624241) and F4 (Ponni × Vengeri) populations of the crosses. Superior lines selected through the pedigree method in terms of marketable yield and resistance to BSFB were identified from the F3 forwarded F4 generation of Ponni × Vengeri, the lines were 1.2.18.8, 1.2.10.7, and 1.3.10.7 (in descending order of their performance). The superior lines with resistance for fruit infestation from F4 generation developed through SSD were 1.3.11.2 (0 %), 1.4.13.2 (50 %), and 1.10.16.4 (0 %). The identified lines from the F4 generation of cross Ponni × Vengeri may be forwarded further to develop resistant varieties and other studies.Item Evaluation of brinjal (Solanum melongena L.) genotypes for resistance to bacterial wilt (Ralstonia solanacearum)(Department of Plant Breeding and Genetics , College of Agriculture, Padannakkad, 2023-12-11) Muslepally Niharika; Namboodiri Raji VasudevanThe current study entitled “Evaluation of brinjal genotypes for resistance to bacterial wilt (Ralstonia solanacearum)” was carried out in the Department of Plant Breeding and Genetics, College of Agriculture, Padannakkad during 2020-2023. The main objectives of the study were to evaluate brinjal genotypes for resistance to Bacterial wilt (BW) and examination of the mechanism of resistance through anatomical and biochemical parameters as well as estimation of yield characters in resistant lines. The experimental material consisted of thirty-one accessions which included eleven accessions (SM-1, SM-2, SM-3, SM-4, SM-5, SM- 8, SM-9, SM10, SM-31, SM-32, SM-33) collected from North Kerala, seventeen accessions (SM-11 to SM-27) from NBPGR. It also included three released varieties and hybrid of KAU (Haritha, Surya, Ponny and Neelima) as resistant checks and two susceptible checks (SM-26[S.incanum] and SM-27[S.insanum]). In experiment I, three weeks old seedlings of all brinjal genotypes were screened for resistance to BW in a completely randomized design with three replications. Based on percentage disease incidence (PDI), two accessions SM-15 and SM-25 were rated as highly resistant (HR: 0 PDI) and accessions SM-1 was rated as resistant (R: 1-10 PDI). Accessions SM-1, SM-2, SM-5, SM-11, SM-17, SM-24 and KAU hybrid Neelima were rated as moderately resistant (MR: 11-20 PDI). Accessions SM-4, SM-8, SM-14 and SM-19 were rated as susceptible (S: 21-30 PDI). Moderately susceptible (MS: 31-40 PDI) accessions were SM-3, SM-32, SM-33, SM-13 and SM-16. Accessions SM-9, SM-10, SM-12, SM 18, SM-20, SM-21, SM-22, SM-23, SM-26 and SM-27 were rated as highly susceptible (HS: >40 PDI). Biochemical parameters viz., Polyphenol oxidase (PPO) enzyme activity, total phenols, and total sugars (both reducing and non-reducing) were assessed at 12 and 24 hours post inoculation (hpi).In this analysis using twenty two accessions consisting of eight genotypes from resistant categories (HR, MR, R) and eight from HS group along with four RC ( Ponny, Haritha, Surya and Neelima) as well as two SC (SM-26, SM-27) were used. A control group with mock inoculation was also part of the analysis. Two factor ANOVA demonstrated significant differences in these biochemical parameters among all tested brinjal genotypes. At 12 and 24 hpi, the most significant rise in PPO activity was observed in the RC followed by the R group, HR germplasm and MR group compared to their respective control samples. Moreover at 24 hpi the resistant (R) genotypes exhibited a significant 3.5-fold increase in PPO activity compared to the control group. Resistant checks exhibited the highest phenolic content followed by the HR, R and MR germplasm at 12 and 24 hpi. The highest amount of total sugars, which includes both reducing and non-reducing sugars, was observed in RC followed by HR germplasm, R germplasm, and MR germplasm after 24 hpi. Correlation analysis revealed a significant negative correlation between biochemical parameters viz., PPO enzyme activity, total phenol content, total sugars including non-reducing sugars (12 and 24 hpi) and disease incidence. A positive correlation was observed between disease incidence and reducing sugars at 12 hpi whereas, negative correlation was observed between the same at 24hpi. The biochemical analysis indicated that PPO and phenols played a positive role in the resistance against R. solanacearum in brinjal. However, the role of sugar content in plant defense is still unclear and requires further studies for a better understanding of sugar metabolism. In the current study different aspects of the stem vascular anatomy viz., number of small and large vessels, total number of vessels, ratio of large to small vessels and average vascular area in the eggplant germplasm and correlation of these characters with disease incidence were analysed. A significant variation for anatomical characters was observed among all the genotypes. Among the germplasm HR accessions SM-15, SM-25 and R accession SM 1 showed highest number of large vessels, higher ratio of large vessels to small vessels and higher average vascular area compared to all other accessions. These anatomical parameters are found to play a significant role in the temporal and spatial distribution of the pathogen within the vascular vessels. After analyzing the response of various brinjal genotypes to disease incidence, as well as considering biochemical and anatomical parameters, it was observed that eight genotypes (SM-1, SM-2, SM-5, SM-11, SM-15, SM-17, SM-24, and SM-25) exhibited resistance against BW. These genotypes along with four KAU released resistant checks were further evaluated in the field in experiment II. Field evaluation was carried out in a randomized block design with three replications for sixteen quantitative and two qualitative characters. Per se performance of all genotypes revealed significant variation for all the quantitative characters indicating presence of high genetic variability. Association analysis revealed that leaf area, root dry weight and average fruit weight showed significant positive genotypic correlation and direct effect depicting true association of these characters with fruit yield. Selection based on these characters will help achieve efficient improvement in fruit yield. Among the local accessions, resistant accession SM-1 exhibited the maximum early fruit yield of 972.68 g followed by the Moderately resistant accession SM-11 (965.77 g). Accession SM-1 was also superior for plant height, earliness, average fruit weight and SM-11 for number of fruits per plant. Therefore, resistant accession SM-1 could be regarded as a promising genotype for potential release as a new variety. Highly resistant accessions SM-15 (oval green fruits with intermediate calyx prickles) and SM-25 (oval purple fruits and no prickles on the calyx), displayed excellent plant and flower characteristics like stem girth, branching, days to first and 50 per cent flowering but reported lower early yields. These can be used in hybridization programs either as parents to develop F1 hybrid or as recombinants in recombination breeding for resistance to bacterial wilt.Item Etiology and management of fruit rot of brinjal (Solanum melongena L.)(Department of Plant Pathology, College of Agriculture, Vellanikkara, 2020-09-30) Aswathy Peethambaran; Sainamole Kurian, PBrinjal belonging to the family Solanaceae is of great importance in human nutrition and is considered as the King of Vegetables. Despite being a versatile crop adapted to various agroclimatic regions and seasons, brinjal is affected by many diseases like Phomopsis blight and fruit rot, little leaf, damping off and bacterial wilt. In addition to these, recently a fruit rot caused by Phytophthora nicotianae is also reported from various parts of India (Jain et al., 1982 and Chowdappa et al., 2015). A preliminary study of the same has been conducted by Jose and Beena (2016). Considering the importance of Phytophthora spp. in the agricultural scenario of Kerala, the present investigation was carried out with the objectives to study the symptomatology and etiology of fruit rot of brinjal, screening popular brinjal varieties for resistance and to develop management strategy for the disease. Purposive sampling survey was conducted in different locations of Thrissur and Palakkad districts during June to October 2019, infected brinjal fruits were collected and symptoms were recorded. The incidence and severity of the disease in different locations ranged from 10 to 84 and 10 to 66 per cent respectively. Presence of a white mycelial growth was consistently observed on the infected fruits which on examination under microscope showed hyaline, coenocytic hyphae and pear shaped sporangia with papillae. The microorganism was isolated on carrot agar and pathogenicity was tested. Symptoms produced on artificial inoculation were also recorded. A total of four isolates of the pathogen were collected, purified and maintained for further studies. The isolates were named after the place of collection as VKA Ⅰ, VKA Ⅱ, KPD and NMA. Cultural and morphological characters of the isolates were studied on three different media viz., carrot agar, potato dextrose agar and coconut water agar. Colony characters like growth rate, colour, shape, texture of colony and sporulation varied among the isolates and media. All the four isolates produced coenocytic, hyaline, branched mycelium and thick walled, hyaline, globose chlamydospores. Non caducous, papillate, ovoid and obturbinate sporangia were borne terminal or intercalary on the sporangiophore in a simple sympodial fashion. Variation in dimensions of sporangia was observed among the isolates grown on different media. Based on morphology, all the isolates were identified as Phytophthora sp. Oospore production was not noticed on pairing of isolates suggesting that these belong to single mating type and express the typical heterothallic behaviour of the genus. Molecular characterisation of the four isolates revealed maximum similarity to P. nicotianae and phylogenetic analysis showed that isolates VKA Ⅰ, VKA Ⅱ and NMA are more closely related than KPD. Host range studies proved that the pathogen can infect other crops like tomato, chilli, bhindi, bitter gourd, arecanut, coconut, nutmeg, cocoa, papaya, rubber and black pepper on artificial inoculation. The most popular varieties of brinjal, released from Kerala Agricultural Universiy viz., Surya and Haritha were found to be susceptible to the pathogen. The results of in vitro evaluation showed that cymoxanil 8%+ mancozeb 64%, metalaxyl+ mancozeb, mancozeb, copper hydroxide, fosetyl- Al at 0.05 per cent concentration and Bordeaux mixture (0.5%) recorded cent per cent inhibition of the pathogen. However, azoxystrobin (0.05%) recorded 37 per cent inhibition only. Similarly Trichoderma sp. and Pseudomonas fluorescens recorded cent per cent and 69.40 per cent inhibition respectively. The leaf extracts of Capsicum frutescens and Boerhavia diffusa also gave significant inhibition of pathogen. In bioassay on detached fruits the highest disease reduction was recorded by mancozeb (72.38%) followed by cymoxanil 8%+ mancozeb 64% (66.26%). However biocontrol agent Trichoderma sp. also recorded 51.67 per cent reduction over control which was on par with fosetyl- Al, copper hydroxide and azoxystrobin. Leaf extract of Capsicum frutescens also reduced the disease by 39.18 per cent. Phytophthora fruit rot is an emerging disease and if left uncontrolled it will be a serious threat to brinjal cultivation. The study has confirmed the etiology and symptomatology of the disease and the wide host range of the pathogen. It was also proved that the four isolates of P. nicotianae collected in the study are confined to same mating type. The investigation has also revealed the efficacy of lower doses of commonly used fungicides, against P. nicotianae. Results of the study also suggested the potential of biocontrol agents and botanicals against the pathogen.Item Magnetized irrigation water for enhancing production of brinjal (Solanum melongena L.)(Department of Agronomy, College of Agriculture, Vellayani, 2022-11-05) Vijayakumar, Pullagura; Sajitha Rani, TThe investigation entitled “Magnetized irrigation water for enhancing production of brinjal (Solanum melongena L.)” was carried out as two experiments at the Instructional Farm, College of Agriculture, Vellayani during 2018-2021, to study the effect of magnetization on quality of irrigation water, to assess the impact of magnetized water on growth, yield and quality of brinjal, to evaluate the effect of magnetized irrigation water on soil properties and to work out the economics. The present investigation revealed that employing magnetic strength of 2000G was effective for getting good quality irrigation water, and scheduling of irrigation with this water at IW/CPE ratio of 0.8 along with 75 per cent RDF could be recommended for obtaining higher growth, yield and monetary returns from both plant and ratoon crop of brinjal.Item Molecular characterization of brinjal (Solanum melongena L.) genotypes and their performance assessment in summer(Department of Genetics and Plant Breeding, College of Agriculture, Padanakkad, 2023-05-31) Chakravaram, Alekhya; Namboodiri Raji VasudevanItem Bioefficacy of Aloe vera (L.) in managing pests of brinjal, Solanum melongena L.(Department of Agricultural Entomology, Vellayani, 2023-04-25) Ajay P, Kumar; Malini, Nilamudeen