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Open Access
Strain improvement of oyster mushrooms- pleurotus cystidiosus O.K. Mill and pleurotus opuntiae (Durieu and LEV.) SACC.
(Department of Plant Pathology, College of Agriculture, Vellayani, 2018) Krishnapriya, P J; KAU; Geetha, D
The present study entitled “Strain improvement of oyster mushrooms: Pleurotus cystidiosus O.K.Mill and Pleurotus opuntiae (Durieu and Lev.) Sacc.” was carried out in College of Agriculture, Vellayani during 2015-2018, with the objective to standardize the techniques for production of oyster mushrooms: P. cystidiosus and P. opuntiae; and to study their morphological, physiological and cultural characteristics as well as nutritional and organoleptic qualities; and to undertake genetic improvement by protoplast fusion. The mushrooms were collected from two locations of Thiruvananthapuram and three fast growing isolates of Pleurotus spp. viz., PC2 (Vellayani), PNC1 (Chirayinkeezhu) and PO1 (Vellayani) were selected for the study. These isolates were identified as P. cystidiosus subsp. abalonus, P. cystidiosus and P. opuntiae using internal transcribed spacer (ITS) primers and subsequent sequencing; and registered at Genbank database with accession numbers KY214254, KY887023 and KY214255 respectively. The fast growing isolates of P. cystidiosus (coremial), P. cystidiosus (non-coremial) and P. opuntiae recorded maximum growth on PDPA amended with one per cent yeast under dark condition. The optimum temperatures for the growth were 30 0C, 25 to 30 0C and 25 0C respectively whereas, the optimum pH were 8, 8 and 7 to 8 respectively. Studies with different substrates and amendments for spawn production revealed that sorghum with one per cent yeast was the best for P. cystidiosus (coremial) and P. opuntiae whereas, paddy grains with one per cent yeast for P. cystidiosus (non-coremial). Experiments with different substrates and amendments for mushroom production revealed that rubber wood sawdust sprayed with 2.5 per cent of 1 M potassium dihydrogen phosphate recorded the maximum BE for P. cystidiosus (non-coremial) (192.76 per cent). P. opuntiae recorded the maximum BE in rubber wood sawdust amended either with 4 per cent neem cake (91.38 per cent) or wheat bran (91.37 per cent). Major insect pests observed in the beds of Pleurotus spp. were phorid flies, spring tails, black ants and staphylinid beetles. The competitor moulds observed were different species of Coprinus, Aspergillus, Penicillium and Trichoderma. Sporocarps soaked in one per cent CA for 15 minutes followed by mechanical drying and powdering was the best post harvest treatment for both P. cystidiosus (non-coremial) and P. opuntiae. Mycelium of P. cystidiosus (coremial) showed black coremial structures, representing its asexual stage (Antromycopsis broussonetiae Pat. & Trab.). The coremia comprised of elliptical (16.31 µm x 7.48 µm) and round conidia (8.06 to 8.49 µm). The black colour of coremia was due to melanin which was extracted (255.56 mg l-1) and characterized. The performance of long duration P. cystidiosus (non-coremial) and short duration P. opuntiae was compared with two ruling mushrooms of Kerala viz., long duration P. florida (Mont.) Singer and short duration P. eous (Berk.) Sacc. The study revealed that P. cystidiosus (non-coremial) and P. opuntiae showed higher BE compared to P. florida and P. eous, respectively. P. cystidiosus (non-coremial) recorded maximum moisture (94.05 per cent), starch (200.55 mg g-1), protein (30.2 mg g-1), fat (4.25 per cent), antioxidants (485.45 μg equivalent gram of ascorbic acid-1), beta-carotene (25.69 µg 100 mg-1), polyphenols (7.55 mg g-1) and energy (359.45 Kcal) compared to other Pleurotus spp. Sensory evaluation of mushroom products made from the species of Pleurotus was done and masala curry prepared from P. cystidiosus (non-coremial) scored the maximum value for overall acceptability. Shelf life of P. cystidiosus (non-coremial) was higher (5 days) compared to P. opuntiae, P. florida and P. eous (3 days each) in perforated poly propylene covers stored under refrigeration. Vanillin (0.05 per cent) and carbendazim (1 mM) were selected as dual biochemical markers for the PEG mediated protoplast fusion. Three days old P. cystidiosus (non-coremial) and four days old P. opuntiae recorded the maximum protoplast yield at five and four hours after incubation respectively with 0.6 M KCl and 30 mg ml-1 of enzyme consortium. Eight fusant lines with varied mycelial characters were obtained. Among fusants, F6 and F8 did not segregate in the second generation whereas, F4 segregated. F6 and F8 recorded higher BE of 168.05 and 99.95 per cent respectively compared to the parental lines and other fusants. Sporocarp of F6 and F8 was morphologically similar to P. cystidiosus (non-coremial) and P. opuntiae respectively; and F8 also exhibited low temperature adaptability. The present investigation indicated the exploitability of two promising isolates viz. P. opuntiae for tropical areas and P. cystidiosus (non-coremial) for cooler regions of Kerala using locally available materials and the standardized cultivation practices. The present study also standardized the protoplast fusion technique between P. cystidiosus (non-coremial) and P. opuntiae; and two fusant lines (F6 and F8) recorded higher BE which can be used for future breeding programmes.
Open Access
Bioefficacy and soil health impact of flucetosulfuron in wet seeded rice (Oryza sativa L.)
(Department of Agronomy, College of Agriculture, Vellayani, 2018) Arya, S R; KAU; Elizabeth, K Syriac
The investigation entitled "Bioefficacy and soil health impact of flucetosulfuron in wet seeded rice (Oryza sativa L.) was carried out at College of Agriculture, Vellayani, Thiruvananthapuram during the period of 2015-2018. The objectives were to evaluate the bioefficacy of flucetosulfuron in wet seeded rice; to assess its impact on soil health by determining the microbial count, earthworm population, enzyme status and herbicide residue in soil through bioassay using indicator plant as well as to assess the weed seed bank. It was also envisaged to study the in vitro sensitivity of biofertilizer organisms and biocontrol agents to flucetosulfuron. Field experiment was conducted during the I and II crop seasons of 2016- ’17, in a farmer’s field in Kalliyoor Panchayat, Nemom block, Thiruvananthapuram district, Kerala, with 12 treatments replicated thrice in Randomized Block Design. The treatments were: T1 : Flucetosulfuron @ 20 g ha-1 at 2-3 DAS, T2 : Flucetosulfuron @ 25 g ha-1 at 2-3 DAS, T3 : Flucetosulfuron @ 30 g ha-1 at 2-3 DAS, T4 : Flucetosulfuron @ 20 g ha-1 at 10-12 DAS, T5 : Flucetosulfuron @ 25 g ha-1 at 10-12 DAS, T6 : Flucetosulfuron @ 30 g ha-1 at 10-12 DAS, T7 : Flucetosulfuron @ 20 g ha-1 at 18-20 DAS , T8 : Flucetosulfuron @ 25 g ha-1 at 18- 20 DAS , T9 : Flucetosulfuron @ 30 g ha-1 at18-20 DAS, T10: Bispyribac sodium @ 25 g ha-1 at 15 DAS, T11: Hand weeding at 20 and 40 DAS and T12 : Weedy check. The short duration variety Kanchana was used for the trial. The weed flora in the experimental field comprised of four species of grasses, six species of broad leaved weeds and three species of sedges. Based on density and dry weight, sedges were the predominant group in the experimental field followed by broad leaved weeds and grasses. Application of flucetosulfuron @ 20, 25 and 30g ha-1 at 10-12 and 18-20 DAS (T4, T5, T6, T7, T8 and T9) recorded lower total weed density, total weed dry weight and nutrient removal by weeds and higher total weed control efficiency and were on par with the hand weeding treatment (T11). Yield reduction due to weeds was found to be 52.33 and 55.61 per cent during the I and II crop seasons respectively. The highest grain yield was recorded by the application of flucetosulfuron @ 25 g ha-1 at 10-12 DAS (T5) and flucetosulfuron @ 20 g ha-1 at 10-12 DAS (T4) during the first and second crop seasons respectively. The same trend was observed in the case of dry matter production also. Pooled analysis of the grain yield for the two seasons indicated the superiority of T5 which recorded the highest grain yield of 8.33 t ha-1. This treatment was on par with the other levels of flucetosulfuron viz., 20 and 30 g ha-1 at 10-12 DAS (T4 and T6) and hand weeding treatment (T11). Higher yield attributes, harvest index and nutrient uptake were also recorded for these treatments. However, net income and B:C ratio were significantly lower for hand weeding treatment. Herbicide application did not cause any significant inhibitory effect on the earthworm population and spider count. Application of herbicides increased the microbial population in herbicide treated plots. Flucetosulfuron, at the tested doses (20, 25 and 30 g ha-1) and time of application (2-3, 10-12 and 18-20 DAS), did not show any adverse impact on the activity of soil enzymes (dehydrogenase, acid phosphatase and urease) and soil organic carbon status. To identify the most suitable indicator plant for assessing flucetosulfuron residue in soil, four separate pot culture experiments were conducted using barnyard millet, cucumber, sunflower and maize. Sunflower was identified as the most sensitive indicator plant and shoot length of sunflower was adjudged as the best parameter to assess the flucetosulfuron residue in soil. Bioassay after each field experiment using sunflower revealed that there was no residual toxicity of flucetosulfuron in the post experiment soil. Pot culture experiments were carried out before and after each field experiment, to study the weed seed bank dynamics. Results revealed that non- herbicidal plots recorded higher weed count compared to herbicide applied plots. In all the herbicide treated plots, effective reduction in weed seed bank could be obtained irrespective of the dose of the herbicide. Regarding the time of application, application of flucetosulfuron at 10-12 and 18-20 DAS caused significant depletion of weed seed bank during both the seasons compared to its application at 2-3 DAS. In vitro sensitivity of biofertilizer organisms viz., Azospirillum lipoferum, Azotobacter chroococcum, Bacillus megaterium and Frateuria aurantia to flucetosulfuron indicated that growth of none of the organisms were significantly inhibited by the tested doses of flucetosulfuron. Similarly, in vitro sensitivity to biocontrol agent Trichoderma viride revealed that, at all the tested concentrations of flucetosulfuron, it showed a colony diameter of 9 mm uniformly with zero per cent inhibition indicating the compatibility of the herbicide. The compatibility studies with Pseudomonas fluorescens also revealed the safety of the herbicide. The present study revealed that application of flucetosulfuron @ 20, 25 and 30 g ha-1 at 10-12 DAS was very effective in controlling the weeds and recorded significantly higher grain yield and monetary benefits in wet seeded rice. Application of flucetosulfuron @ 20, 25 and 30 g ha-1 at 2-3/10-12/18-20 DAS had no adverse impact on soil health and was found compatible with the tested biofertilizer organisms (Azospirillum lipoferum, Azotobacter chroococcum, Bacillus megaterium and Frateuria aurantia) and biocontrol agents (Trichoderma viride and Pseudomonas fluorescens).
Open Access
Breeding cowpea (Vigna unguiculata (L.) Walp.) for resistance to spotted pod borer (Maruca vitrata Fab.)
(Department of Plant Breeding and Genetics, Vellanikkara, 2018) Ambavane Ajinkya Rajendra; KAU; Jiji Joseph
Cowpea [Vigna unguiculata (L.) Walp.] is important pulse crop rich in nutrients, especially proteins. This crop is cultivated in the tropics of Asia, Africa and other parts of the world. Nevertheless, the production of cowpea is unable to achieve its summit. One of the prime reasons for this is the infestation of a notorious pest, the spotted pod borer, (Maruca vitrata Fab.; Lepidoptera: Crambidae). Spotted pod borer is one of the most important post-flowering pests of cowpea in the tropics. It is a major lepidopteran pest and damage cause to cowpea by the pest almost always crosses economic threshold level. Hence, the present investigation was conducted in the Department of Plant Breeding and Genetics, College of Horticulture, Vellanikkara, Kerala Agricultural University, Thrissur during 2015 to 2018 with the objective of identification and incorporation of resistance against spotted pod borer in high yielding varieties of cowpea and assessment of parental polymorphism at the molecular level Thirty genotypes of cowpea formed the material for the study. These genotypes were subjected to field screening against spotted pod borer. These genotypes were also evaluated for morphological and biochemical basis of resistance. Five selected genotypes from experiment 1 then hybridised with four high yielding genotypes viz., Geethika, Vellayani Jyothika, Lola and Kashi Kanchan following Line × Tester mating design. Twenty F 1 hybrids evaluated for field resistance and the morphological basis of resistance. Progenies of selected F 1 hybrids grown as F 2 populations and evaluated for same parameters as like F 1 s. Thirty genotypes were also subjected to molecular screening by 40 SSR primers. Wide variation was observed in terms of different damage parameters. Ten genotypes viz., Hridya, Palakkadan thandan payar, EC 300039, EC 98668, EC 101216, IC 52110, IC 39945, IC 2918, IC 39922 and IC 39916 recorded total damage below five per cent. Among them, IC 39922 observed to have no flower bud and flower damage, EC 300039, EC 98668, IC 52110, IC 39945, IC 2918 and IC 39916 recorded no flower damage, whereas, Palakkadan thandan payar, IC 39945, IC 2918 and IC 39947 were free from pod damage. The highest damage was recorded in the variety Bhagyalakshmy (48.46 %) followed by variety Lola (30.04 %). Analysis of the morphological basis of resistance to spotted pod borer revealed the negative correlation of trichome density and length on flower bud, trichome density on the pod and pod wall thickness with respective damage parameters. With respect to the biochemical basis of resistance to spotted pod borer, total sugar content, reducing sugar content and non-reducing sugar content of flower bud and pod showed a positive correlation with damage parameters, but the correlation was not significant. However, the total protein content of pod showed a strong and positive correlation with pod damage. Total phenol content of flower bud showed strong negative correlation with damage parameters. Polyphenol oxidase activity in flower bud and pod exhibited a strong negative correlation with damage parameters. The crude fibre content of pod also showed a strong negative correlation with pod damage. In experiment 3, three SSR primers viz., CLM0061, CLM0295 and CLM0300 recorded high polymorphic information content (0.70, 0.71 and 0.76, respectively). Primer CLM0190 observed to have high amplicon size (307.03-415.73 bp). Jaccard’s similarity coefficient was highest between IC 52118 and IC 39916 (0.643) and was lowest between Kashi Kanchan and TVX-944 (0.022). Cluster analysis of SSR data grouped 30 genotypes in 22 clusters, and the 21 st cluster was observed to have more members (3 genotypes). Most resistant genotype, IC 2918, grouped in a separate cluster which proved its diverse nature from other genotypes. Principal component analysis of SSR data placed three yard-long bean genotypes viz., Geethika, Vellayani Jyothika and Lola near to each other in a two-dimensional score plot. The same analysis also formed two clusters with more number of genotypes which placed resistant and susceptible genotypes separately. In field screening of F 1 hybrids, Hybrid 20 observed to have total damage below 5 per cent. Eight hybrids recorded total damage in the range of 5 to 10 per cent. These hybrids were selected for next experiment. Line × Tester analysis of F 1 s revealed Kashi Kanchan, EC 98668 and IC 2918 as a good combiner for resistance against spotted pod borer. Hybrid 5, Hybrid 6, Hybrid 10, Hybrid 11, Hybrid 13, Hybrid 15, Hybrid 16, Hybrid 17, Hybrid 18, Hybrid 19 and Hybrid 20 observed to have desired negative heterosis (mid-parent) for total damage. In F 2 plant screening, Hybrid 1 population recorded low mean for total damage (6.76 %), whereas, the population of Hybrid 3 recorded high mean (12.17 %). Around 100 plants of F 2 generation recorded total damage below ten per cent. Out of them, around 38 plants also registered good yield. These plants should be further evaluated to isolate high yielding resistant segregants.
Open Access
Profiling bioactive compounds and nutrients in jackfruit (artocarpus heterophyllus Lam.) and developing a jackfruit based textured vegetable protein
(Department of Community Science, College of Agriculture, Vellayani, 2018) Anila, H L; KAU; Suma Divakar
The investigation entitled “Profiling bioactive compounds and nutrients in Jackfruit (Artocarpus heterophyllus Lam.) and developing a jackfruit based textured vegetable protein‟‟, was carried out at College of Agriculture, Vellayani, Thiruvananthapuram during the period of 2015-2018. The objectives of the study were to ascertain the bioactive compounds and nutrients present in different jackfruit types. The study also envisaged the improvement of digestive quality of jackfruit through reduction of oligosaccharides and developing a jackfruit based textured vegetable protein. The study was conducted in three experiments; viz. analysis of nutrient and chemical profile along with antioxidant activity of the selected types of jackfruit; analysis of measures for reducing antinutrients in raw jackfruit and development of raw jackfruit based textured vegetable protein. For the component wise analysis, five types of jackfruits viz Muttom varikka, Then varikka, Sindoor, Chempikalom varikka and Local cv Koozha were selected; their raw and ripe stages as well as both bulbs and seeds were analysed separately. Analysis of proximate composition, vitamins, minerals, bioactive compounds, antinutrients and antioxidant activity were covered in the first experiment. The results showed that nutrient wise, raw seeds of Chempikalom and ripe bulbs of Sindoor scored higher than the rest of treatments while with respect to antioxidant activity, ripe seeds of Koozha were better than other treatments. The profiling of nutrients and bioactive compounds in the each part of the experiment is an eye opener on specific features of the common jackfruit type that can be exploited according to varying needs. The delicacy factor for non acceptability of jackfruit, despite its useful composition is that, it has a flatulence factor. This study has thrown light in to the measures to reduce these causative factors. For this purpose in the second part of the experiment, one treatment is with enzyme α galactosidase and another treatment with Saccharomyces cerevisiae was carried out on milled raw jackfruit bulbs and seeds of cv koozha to reduce the level of anti nutrients. Enzyme α galactosidase was premixed with the dry flour of jackfruit seed and jackfruit bulb separately in the ratio 1:100 and the moisture level was varied from 25 – 200% (dough to batter stage). The hydrolysis was carried out for 90 minutes in both jackfruit bulb flour and seed flour. The products were evaluated for the breakdown of oligosaccharides (Raffinose) using HPTLC method. The results showed that the level of Raffinose after treatment with bulb flour and seed flour was seen to decrease with increase in moisture content (25-100%). Thereafter the content slightly staggered and then reduced (125%, 150%, 175%, 200%). However the level of oligosaccharide decreased in comparison to levels in control (0.97 μg g-1). When flours were to be made into batter and subjected to fermentation with Saccharomyces cerevisiae @ 5g/kg for 6 hrs, 8 hrs and 12 hrs and analyzed through HPTLC assay; raffinose content in jackfruit bulb flour reduced from 0.75 μg g-1 to 0.63 μg g-1, 0.58 μg g-1 and 0.74 μg g-1 after 6, 8 and 12 hours respectively. Raffinose content in jackfruit seed flour reduced from 1.28 μg g-1 to 0.42 μg g-1, 0.31 μg g-1 and 0.62 μg g-1 respectively after 6, 8 and 12 hours of fermentation. Considering the reduction of raffinose content and sensory evaluation of the treated flour, eight hour fermentation (F2) was selected as the best treatment. The demand for convenience foods among the literate consumers is on the rise around the globe. It has been argued that convenience is a barrier to achieving proper nutrition using adequate servings. In order to incorporate the fruit based nutritional benefits, it has become important to develop newer and novel foods that could reach the consumers‟ acceptance. With this background an attempt was visualized to develop jackfruit based textured vegetable protein (TVP) to make jackfruit more popular among the health conscious people. In the third experiment, Jackfruit based TVP was formulated by using the ingredients - jackfruit bulb flour and seed flour along with gluten, yeast and soya flour to form chunks using standardized methods. Totally eleven combinations of TVP were worked out. All the eleven treatments were cooked and evaluated by a panel of ten members. Based on the sensory attributes such as appearance, colour, flavour, texture, taste and overall acceptability, the highest score was obtained for T7 which was followed by T8 and these two treatments were seen to be on par. The lowest score was obtained by treatment T4; T7 was taken up for quality analysis, it had a protein content of 61.50g, carbohydrate content of 34.97g and lesser cooking time (7.33 minutes). The physico chemical and textural qualities were on par with soyachunks available in the market. Processed TVP showed good storage stability up to three months. The third part of the study concluded with a positive note on scope of commercializing this jackfruit based protein concentrate. The product is both novel and healthy, raising its popularity for sailing up. Thus, the study finds that there is variation in jackfruit types with respect to nutrients, chemical and bioactive compounds. The efficacy of enzyme α galactosidase and Saccharomyces cerevisiae to reduce oligosaccharide levels in jackfruit flour is feasible. With high acceptable food like meat analogue was also standardized based on jackfruit flours, which can be recommended for commercialization.
Open Access
Integrated management of viral diseases of bittergourd (momordica charantia L.)
(Department of Plant Pathology, College of Agriculture, Vellayani, 2018) Radhika, N S; KAU; Umamaheswaran, K
The present research work entitled ‘Integrated management of viral diseases of bitter gourd (Momordica charantia L.) was carried out in the College of Agriculture, Vellayani during 2014-2017, with the objectives to study the occurrence and distribution of viruses in bitter gourd in Thiruvananthapuram, Idukki and Palakkad, immunomolecular characterization of the viruses, and screening of antiviral chemicals, antiviral principles of animal, plant and microbial origin for the management of the disease. In the suvey conducted at five locations in Thiruvanaanthapuram district, Pappanchani area recorded highest incidence of viral disease (60%) while highest Vulnerability Index (V.I) was recorded from Vellayani (56.00). In Idukki district, six major bitter gourd cultivating areas were surveyed among which Rajakumary area recorded the highest disease incidence (100%) and V.I (82.00). In Palakkad district, five locations were surveyed, among which panackatri and Thekkepotta recorded highest disease incidence of 88% and highest V.I (69.00). The major insects associated with the crop were whitefly (Bemisia tabaci (Genadius) with an incidence of 10-25%, aphids (Aphis gossypii glover) with an incidence of 10-40%, Jassids (Empoasca (Empoasca) motti Pruthi) with an incidence of 10-30% and mites with an incidence of 10-50%. Phyllody and little leaf symtoms (20% incidence) were also recorded in bittetgourd form Rajakumary and Rajakkad areas in Idukki. Flat limb and multiple proliferation of shoot tip were observed at many fields in Idukki. Symptoms associated with the disease include yellow mottle, mosaic,blistering, leaf curl and reduction in leaf size. Yellow mosaic and blistering is seen in severe infection finally leading to stunting of the plant, reduced flowering an fruiting and hairyness on stem. Mechanical transmission of the virus on Datura stramonium produced yellow lacal lesions indicating the presenceof Bean Golden mosaic virus (Begomo) in the infected leaf extract. This leaf extract also produced local lesions on othe indicator hosts like Chenopodium amaranticolor and Gomphrena globosa indicating the presence of Cucumber mosaic virus (CMV) or Potato virus Y (PVY). The viruses were transmitted by whiteflies (20%) and aphids (30%) from infected bittetgourd plants to healthy seedlings. Whiteflies (Bemisia tabaci Gennadius)) and aphids (Aphis gossypii Glover) are the vectors of the respective viruses Wedge grafting diseases scion on to 3-5 leaf stage healthy seedling of bittergourd produced symptoms of infection within ten days. KAU varieties Preethi and Priyanka were found to be susceptible to infection with preethi expressing a V.I of 70.80 and Priyanka expressing a V.I of 62.50 respectively. Ensyme linked immunosorbent assay (ELISA) and Dot immunobinding assay (DIBA) revealed the presence of three viruses belonging to Begomo, CMV and PVY group causing an mixed infection in bittergourd. The presence of all the three viruses were also confirmed in electron micrograph, Begomovirus as twin particles of size 18-20 X 30nm,CMVas single particles of 18nm and PVY as lonog flexuous rod of size 750nm. PCR amplification of coat protein gene (cp gene) of virus isolates from all the three districts yielded an amplicon of size approximately equal to 570 bp. Idukki and Palakkad isolates showed 94% identity to Tomato leaf Curl Virus isolate TNUDU BGI Coat Protein (AVI) gene while Trivandrum isolate showed 95% identity to Tomato leaf Curl Virus isolate TNPDU BG4 Coat Protein (AV1) gene . Phylogenetic tree constructed using multiple sequence alignment programme showed close relation between Begomo viruses identified in bittergourd from different districts. Studies on defense related enzymes such as peroxidase (PO), polyphenol oxidase (PPO) and phenyl alanine ammonialyase PAL) showed significant activity of PO and PPO in diseased plants than in healthy plants and the activity was on par in healthy and diseased for PAL. Protien profile of healthy and diseased at different days after virus inoculation through grafting indicated the production of novel proteins in diseased. There was no difference in the native profile of peroxidase in healthy and diseased at 15 days after virus inoculation. An additional isozyme band with a Rm value of 0.5 was observed in diseased at 45 days after virus inoculation. Management of the disease with antiviral chemicals and antiviral principles of plant, animal and microbial origin was undertaken as pot culture studies with pre and post inoculation of treatments. Twelve treatments with three replications each were laid out in completely randomized design for the evaluation. The treatments included Aspirin at two levels of 100 and 150 ppm, Salicylic acid (SA) at two levels of 100 and 150 ppm and Acibenzolar S methyl (ASM) at 50 and 75 ppm concentration, and two commercial formulations viz., Perfect and virus –Ex at 0.5 and 1.0 ml concentrations. The treatments were applied three times at 10 days interval. Pre application of thrice sprapying of Acibenzolar S methyl (ASM), 75 ppm concentration (V.I-35.00) at ten days interval was statistically significant over other treatments followed by ASM-50 ppm (V.I-41.33). Post application of antiviral chemicals also showed a statistically significant effect of three times spraying ASM-50 ppm(V.I-25.00) at ten days interval followed by spraying of Virus Ex 1ml L-1 (VThe best eight treatments with control was laid out as Randomised Block Design at the Instructional Farm, College of Agriculture, Vellayani during February to May 2017 as a field trial to study the effect of treatments on natural incidence of the viruses in the susceptible variety Preethi. The treatment, three sprays of ASM-50 ppm (V.I-28.33) at ten days interval ws on par with buttermilk (Three times dilution of curd) (V.I-39.16). Yield was also significantly high in ASM-50 ppm (437g plant-1) followed by Pseudomonas fluorescens talc based formulation (2%) (233 g plant-1)among the treatments.
Open Access
Evaluation and utilisation of edible lichen parmotrema tinctorum (Nyl.) hale for food preservation
(Department of Post Harvest Technology, College of Horticulture, Vellanikkara, 2018) Anupama, T V; KAU; Sheela, K B
Investigation on “Evaluation and utilisation of edible lichen Parmotrema tinctorum (Nyl.) Hale for food preservation” was carried out in the Department of Post Harvest Technology, College of Horticulture ,Vellanikkara during 2014-2017. The main objectives of the study were to evaluate the biochemical constituents, proximate composition, antimicrobial activity, feasibility for food preservation and to study the toxicological effect of the lichen Parmotrema tinctorum. The lichen samples were collected from Chembra, Meppadi, Moolankavu and Ambalavayal areas in Wayanad district, and they were identified as Parmotrema tinctorum by colour spot tests. The samples read K-, C+, KC+ and Pd- for the lichen Parmotrema tinctorum. The habitat of lichen was found to be the shady places of the evergreen forests at 736m -2100m above MSL. Parmotrema tinctorum is found to be corticolous (growing on the surface of trees) in habit. Thallus of the lichen is foliose, loosely attached, lobes irregular, margins entire, upper surface grey, smooth, shining; lower surface black and marginal area brown. Proximate analysis of Parmotrema tinctorum revealed a high content of total protein (15.70 %), crude fibre (14.16%), ash (10.50%) and total phenols (322 mg/100g). Parmotrema tinctorum also contained total carbohydrate (20.03 g/100g), crude fat (1.28%), ascorbic acid (4.66 mg/100g) and total free amino acids (8.25 mg/g). High content of calcium, magnesium, potassium and iron were found in the mineral analysis of Parmotrema tinctorum. Methanol, ethyl acetate and acetone extracts of Parmotrema tinctorum were analysed for antioxidant activity by DPPH and ABTS assays, and the highest scavenging action was detected in the methanol extract against the DPPH free radicals (IC50-1.47 mg/ml) and the ABTS radicals (IC50-1.27 mg/ml). Preliminary phytochemical screening of Parmotrema tinctorum revealed maximum phytochemicals in methanol extract viz. carbohydrates, phenols, flavonoids, tannins, terpenoids, fixed oils and coumarins. The TLC profiling of lichen extracts (hexane, methanol and acetone) showed maximum compounds in acetone extract, and the spots indicated the presence of phenols and terpenoids. A range of volatile compounds were observed when the lichen extracts (methanol, hexane, acetone, chloroform and ethanol) were subjected to GC-MS analysis.Volatile compounds with antimicrobial properties identified were orcinol, methyl orsellinate, atraric acid, atranorin, methyl haematommate, glyceryl trilaurate, lauric acid vinyl ester and gamma-sitosterol. In vitro testing of antimicrobial activity of acetone, ethanol and chloroform extracts of Parmotrema tinctorum using disc and well diffusion methods revealed their inhibitory action against the selected food spoilage organisms. Ethanol extract (EE) of Parmotrema tinctorum produced maximum inhibition of Aspergillus niger, while chloroform extract (CE) produced maximum inhibition of Aspergillus oryzae. The growth of both yeast species, Saccharomyces cerevisiae and Zygosaccharomyces bailii, was found to be inhibited maximum by the ethanol extract followed by the chloroform extract of the lichen Parmotrema tinctorum. In both disc diffusion and well diffusion methods, the growth of Bacillus subtilis and Staphylococcus aureus were remarkably inhibited by the acetone extract (AE) followed by chloroform extract (CE) forming zones of inhibition at all the concentrations tested. Feasibility of utilizing Parmotrema tinctorum for food preservation was evaluated by adding in powder and in ethanol extract form in two processed products viz. lime pickle and tomato sauce. In lime pickle, bacterial count was least in treatments T8 and T7 (added with 0.3% and 0.2% ethanol extracts respectively). Product preserved with 250 ppm sodium benzoate (T2) revealed least fungal count (0.6x103 CFU/g), which was on par with that containing 0.3% ethanol extract (1.0x103 CFU/g). Lowest yeast count was observed in T8, followed by T2 (0.3 x103 CFU/g). The shelf life of lime pickle treated with T2 (product preserved with 250 ppm sodium benzoate) was estimated to be six months, while that of T8 (product treated with 0.3% ethanol extract) was found to be five months. Unpasteurised tomato sauce in which 0.1% ethanol extract was added had significantly lower bacterial count (5.2X106 CFU/g). The tomato sauce preserved with 750 ppm sodium benzoate recorded lowest fungal and yeast count. The products added with 0.05% and 0.1% ethanol extract of lichen also recorded lower fungal and yeast counts. Microbial analysis of products showed the relevance of ethanol extract as an alternative to sodium benzoate in preventing the microbial spoilage of foods. Sensory analysis revealed that lichen extract added products were acceptable for consumption. Acute oral toxicity study of the ethanol extract of Parmotrema tinctorum conducted in Wistar rats revealed the absence of clinical signs of toxicity and mortalities. There were no treatment related changes in body weight and gross pathological changes in the test animals. Single dosing of ethanol extract of Parmotrema tinctorum upto a dose of 2000 mg/kg body weight orally was found to be safe in Wistar rats.
Open Access
Diversity analysis in landraces of rice(oryza sativa L.) in Wayanad through morphological and molecular polymorphism study
(Department of Plant Breeding and Genetics,College of Horticulture, Vellanikkara, Thrissur, 2018) Manjunatha, G A; KAU; Elsy, C R
The present investigation entitled “Diversity analysis in landraces of rice (Oryza sativa L.) in Wayanad through morphological and molecular polymorphism study” was conducted at the Department of Plant Breeding and Genetics, College of Horticulture, Vellanikkara, Thrissur and Regional Agricultural Research Station, Ambalavayal, Wayanad during the period 2015- 2018. The study aimed to collect and characterize the rice landraces of Wayanad at morphological level and also to characterize the popular aromatic genotypes of the area at molecular level. DUS characterization revealed that, all the landraces under the study exhibited presence of leaf collar, absence of anthocyanin colouration of leaf collar, presence of leaf ligule, split shape of leaf ligule, absence of anthocyanin colouration for plant parts like lemma (keel), area below apex of lemma, stem nodes and presence of secondary branching in panicle. Variability was exhibited for majority of characters namely coleoptile colour, basal leaf sheath colour, intensity of green colour of leaf, anthocyanin colouration of plant parts like leaf, leaf sheath, auricles, ligules, lemma apex, area below apex of lemma, distribution of anthocyanin colouration in leaf, pubescence of leaf blade surface, leaf auricles, culm attitude, density of pubescence of lemma, colour of stigma, attitude of flag leaf blade, curvature of main axis of panicle, lemma and palea colour, presence and colour of awns, distribution of awns in panicle, secondary branching in panicle, attitude of branches in panicle, panicle exsertion, leaf senescence, sterile lemma colour, shape, colour and aroma of decorticated grain, gelatinization temperature and lodging nature.Thavalakannan, Mullan puncha and Sugandhamathi exhibited distinct morphological characters. Among the 60 landraces, Kanni kayama, Ambalavayal-1, Kothandan, Onamottan, Thondi-2, Chenthadi, Kannali and Thondi-1 exhibited significantly high grain yield per plant, which was on par with that of Uma and Aathira (high yielding check varieties), indicating the possibility of commercial cultivation of these cultivars. High PCV value than GCV for all the characters under study, indicated the influences of environmental factors on the characters. High heritability and high genetic gain was exhibited by the characters like length of leaf blade, width of leaf blade, stem thickness, stem length, number of tillers per plant, number of panicles per plant, length of panicle main axis, number of spikelets per panicle, number of grains per panicle, seed setting (per cent), 1000 grain weight, grain length, grain L/B ratio, decorticated grain L/B ratio and grain yield per plant, indicating that these characters could be used in crop improvement programmes. Character association studies including correlation and path-analysis revealed that, five characters viz., width of leaf blade, stem length, number of panicles per plant, weight of 1000 grains and decorticated grain width showed both positive correlation and positive direct effect on grain yield per plant. Cluster analysis based on qualitative characters categorized 60 landraces into 11 clusters at 74 percent similarity level. Based on D2 statistics analysis, the landraces were grouped into seven clusters with variable number of landraces in each cluster, indicating wide genetic diversity in the Wayanad landraces. All the inter-cluster distances were higher than the intra-cluster distance, indicating the wider genetic diversity among landraces of different clusters. Molecular characterization of aromatic rice genotypes of Wayanad by SSR (RM) profiling revealed high level of genetic polymorphism among the genotypes studied. Out of 86 SSR markers used for molecular characterization, 44 markers were polymorphic and remaining 42 were monomorphic. Maximum number of amplicons was exhibited by RM247 with five amplicons, followed by RM85, RM251, RM248 and RM493 with four amplicons each. The highest PIC value was exhibited by RM247 (0.90), followed by RM85, RM251 and RM493 with 0.88 PIC value each. Out of 86 SSR (RM) markers, 21 markers distinguished Basmati from traditional aromatic landraces of Wayanad viz., Gandhakasala and Jeerakasala. Seven SSR markers distinguished Gandhakasala from Jeerakasala, whereas 23 markers distinguished Basmati from Jeerakasala. Twenty-two markers distinguished Basmati from Gandhakasala and 23 markers distinguished aromatic group from non-aromatic group. Cluster analysis for molecular characterization revealed maximum similarity coefficient (1.00) within all the Jeerakasala morphotypes and all the Gandhakasala morphotypes. Cluster analysis effectively differentiated Basmati, Jeerakasala, Gandhakasala, Uma and Aathira from each other. Among the five clusters formed, cluster III was the largest one comprising all the 12 Gandhakasala morphotypes, followed by cluster IV with all Jeerakasala morphotypes. Cluster I, Cluster II and Cluster V exhibited one genotype each namely Aathira, Uma and Basmati, indicating their genetic distinctness.
Open Access
Dissipation and risk assessment of select insecticides used for pest management in cabbage and cauliflower
(Department of Agricultural Entomology, College of Agriculture, Vellayani, 2018) Anju Padmanabhan; KAU; Ambily Paul
Studies on “Dissipation and risk assessment of select insecticides used for pest management in cabbage and cauliflower” was conducted in College of Agriculture, Vellayani, Cardamom Research Station, Pampadumpara and farmers field at Kalliyoor during 2015-2018. The present research work was under taken to study the dissipation of select insecticides viz., chlorantraniliprole 18.5 % SC, flubendiamide 39.35 % SC, indoxacarb14.5 % SC, emamectin benzoate 5 % SG, fipronil 5 % SC, quinalphos 25 % EC, cypermethrin 10% EC, acetamiprid 20% SP, thiamethoxam 25 % WG and dimethoate 30 % EC in cabbage and cauliflower, to assess their potential risks to human health, to determine their effect on soil microbial activity, to estimate the residues in cooked samples and to evaluate the efficacy of “Veggie Wash” to eliminate residues. Survey conducted among 25 each of farmers cultivating cabbage and cauliflower in plain (Thiruvananthapuram) and hill (Idukki) representing two agro climatic conditions revealed that pest infestation was more in hills when compared with plains. Accordingly, pesticide usage was higher in Idukki (84 % each) than in Thiruvananthapuram district (12 and 8 %) in cabbage and cauliflower respectively. Dissipation studies of insecticides having label claim for cabbage and cauliflower under CIB & RC in two agroclimatic regions of Kerala viz., Thiruvananthapuram and Idukki showed that the degradation of insecticides varied with crop and chemistry of the insecticides. Insecticides persisted more in cabbage under plain were flubendiamide (20 days) followed by acetamiprid and quinalphos (10 days each), while in hills, higher persistence was observed in flubendiamide, cypermethrin and quinalphos (10 days each). The lowest persistence was observed in fipronil (3 days) in cabbage under plains and acetamiprid (3 days) in hills. In cauliflower higher persistence was observed for flubendiamide, chlorantraniliprole and dimethoate in plains and flubendiamide, quinalphos (20 days each) and cypermethrin (15 days) treated plots in hills. The lowest persistence was observed for emamectin benzoate (3 days) in cauliflower under plains and hills. Risk assessment study was carried out in cabbage and cauliflower using selected insecticides under plains and hills by comparing the values of Theortical Maximum Residue Concentration (TMRC) and Maximum Permissible Intake (MPI). The result revealed that consumption of dimethoate and fipronil treated cabbage and cauliflower were found to be risky to the end users. However, all other insecticides are safe even on the same day of insecticide application. Effect of insecticides on soil microbial activity was studied in cabbage and cauliflower through the activity of urease, phosphatase and dehydrogenase enzymes. Lower reduction in urease activity was observed in flubendiamide, dimethoate and thiamethoxam treated plot and higher reduction was recorded in fipronil and quinalphos treated plots over control both in cabbage and cauliflower. However, lower reduction in phosphatase activity was recorded in flubendiamide, thiamethoxam and cypermethrin and higher reduction was observed in indoxacarb and fipronil treated plots over control. Lower reduction in dehydrogenase activity was recorded in cypermethrin, acetamiprid and thiamethoxam treated plots and higher reduction was recorded in indoxacarb and fipronil treated plots over contol in both cabbage and cauliflower. Study on extent of removal of insecticides through cooking from cabbage and cauliflower was conducted with insecticides which had more persistence revealed that 15 min cooking removed more residues and the highest removal was observed for quinalphos (54.79 %) in cabbage under plains and cypermethrin (66.47 %) in hills. However, in cauliflower the highest per cent removal was observed for chlorantraniliprole (44.78) in plains and cypermethrin (52.32 %) in hills. “Veggie wash” technology was evaluated in the cabbage and cauliflower after application of insecticides at recommended doses revealed that dipping of cabbage and cauliflower in one per cent “Veggie Wash” solution for 10 min. followed by water wash removed 12-40 per cent of treated insecticides while water wash alone removed 9 -35 per cent. The present study revealed that the dissipation pattern of insecticides varied with crop, agro climatic areas, and chemistry of the molecules. Risk assessment study shown that insecticides viz., fipronil and dimethoate posed risk on human health even at recommended dose. Studies on effect of insecticides on soil enzyme revealed that except fipronil and indoxacarb, all other insecticides under present study have less impact on soil enzymes. Decontamination studies showed that cooking at 15 min. removed 50-60 per cent of insecticides and “Veggie Wash” removed 12-40 per cent of treated insecticides. Present study urged the need to evaluate the new insecticides carefully, by considering safety to environment and human health. The risk assessment studies of all insecticides should be done before going for field level recommendations.
Open Access
Distant hybridization and compatibility studies in wild orchids
(Department of Plant Breeding and Genetics, College of Agriculture, Vellayani, 2018) Seeja, G; KAU; Arya, K
The present investigation entitled “Distant hybridization and compatibility studies in wild orchids” was carried out with the objective of studying the cross compatibility through distant hybridization in wild orchids and molecular characterization of hybrid seedlings using RAPD/ISSR- markers. The study was carried out at Saraswathy Thangavelu Extension Centre of KSCSTE- JNTBGRI, Puthenthope, Thiruvananthapuram and at College of Agriculture, Vellayan, Thiruvananthapuram. The research work included experiment I, II, III and IV. Experiment I was carried out in two parts as evaluation of parents and hybridization, experiment II was cross compatibility studies of selected species, experiment III was in vitro culture of resultant hybrids and evaluation of seedlings and experiment IV was molecular characterization of hybrids. In experiment I, wild types belonging to different genera/species namely Vanda (Vanda tessellata, Vanda spathulata, Vanda sp.), Rhynchostylis retusa, Spathoglottis (Spathiglottis albida, Spathoglottis unguiculata, Spathoglottis gracilis, Spathoglottis plicata), Aerides ringens and Arundina graminifolia available at the orchid conservatory of Saraswathy Thangavelu Extension Centre of JNTBGRI, Puthenthope, Thiruvananthapuram were selected as parents based on variability in floral characteristics and these were evaluated for various quantitative and qualitative characters. Statistical analysis was carried out in Completely Randomized Design and analysis of variance revealed highly significant differences for all the biometrical characters included in the evaluation. Estimation of components of variance revealed that Phenotypic Coefficient of Variation (PCV) was higher than both Genotypic Coefficient of Variation (GCV) and Environmental Coefficient of Variation (ECV) for all the traits studied. PCV (143.93) and GCV (128.52) were the highest for number of spikes plant-1. Heritability was the highest for flower width (99.06 %) and it was high for all thirteen traits. Genetic advance as percent of mean was high for all the traits studied. It was the highest for number of spikes plant-1 (239.80). Estimated phenotypic correlation coefficient revealed highly significant and positive association between flower length and flower width (0.9519). The highly significant and negative association was obtained between internodal length and days for inflorescence emergence to first flower opening (-0.6896). Similarly genotypic correlation coefficient exhibited highly significant and positive association between flower length and flower width (0.9545) and highly significant and negative association between plant spread and number of leaves plant-1 (-0.9903). Based on this, parents were selected and were crossed in all possible combinations. In Vanda a hybrid evolved from the wild species was available at the centre and it was also crossed with the wild parents to study the cross compatibility of wild species with hybrids. In experiment II, cross compatibility of 152 cross combinations made was studied based on successful capsule setting. Capsule characteristics were recorded. The genus Spathoglottis took only four days for attaining pod setting whereas for the genus Rhynchostylis it was ten days for pod setting. Capsule attained maturity much earlier (30 days) in the genus Spathoglottis but the species Vanda spathulata took more days for attaining capsule maturity i.e., harvesting stage (150-154 days). In experiment III, capsules developed among thirty one cross combinations were subjected to seed culture for rapid germination under in vitro condition and seedling development. Observations regarding seed germination were recorded and seeds of ten crosses exhibited seed greening and initiation of protocorm development. Seeds of seven cross namely one intergeneric hybrid and six interspecific hybrids were developed into seedlings. Evaluation of hybrid seedlings was made based on variability in morphological characters at monthly intervals. The six interspecific hybrids were Spathoglottis unguiculata x Spathoglottis albida (Culture 622), Spathoglottis gracilis Spathoglottis unguiculata (Culture 652), Spathoglottis albida x Spathoglottis unguiculata (Culture 778), Spathoglottis albida x Spathoglottis unguiculata (Culture 1368), Spathoglottis plicata x Spathoglottis unguiculata (Culture 1386), Spathoglottis unguiculata x Spathoglottis plicata (Culture 1388) and intergeneric hybrid was Spathoglottis unguiculata x Vanda sp. (Culture 679). In experiment IV, molecular characterisation of seedlings evolved through the crossing was done based on ISSR analysis to distinguish F1 hybrid seedlings from selfed seedlings and their parents. Percentage of polymorphism between hybrids and parents ranged from 11.99 to 32.97 and these results confirmed that all the seven crossed seedlings tested were F1 hybrids and these were distinct from their relevant parents. The above study revealed that through distant hybridization in wild orchids, one intergeneric hybrid Spathoglottis unguiculata x Vanda sp. and six interspecific hybrids viz., Spathoglottis unguiculata x Spathoglottis albida, Spathoglottis gracilis x Spathoglottis unguiculata, Spathoglottis albida x Spathoglottis unguiculata, Spathoglottis albida x Spathoglottis unguiculata, Spathoglottis plicata x Spathoglottis unguiculata, Spathoglottis unguiculata x Spathoglottis plicata could be obtained and molecular characterization confirmed the hybridity of the intergeneric and interspecific hybrids. Therefore, the intergeneric and six interspecific F1 hybrids evolved through distant hybridization can be carried forward for the development of varieties or can be utilised for genetic improvement programme in future.

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