Browsing by Author "Simi, S"

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Characterisation of traditional mango (mangifera indica L.) varieties of southern Kerala
(Department of Pomology and Floriculture, College of Agriculture, Vellayani, 2006) Simi, S; Rajmohan, K
Attempts were made at the Department of Pomology and Floriculture and the Department of Plant Biotechnology, College of Agriculture, Vellayani during June 2003 to December 2005 for characterizing the traditional mango (Mangifera indica L.) varieties of southern Kerala. Field visits were made in order to locate the varieties, to conduct survey and to collect the research materials. Fifty varieties were located in the four districts of southern Kerala, Trivandrum (17), Kollam (10), Pathanamthitta (6) and Alappuzha (17). Wide variability could be observed in the vegetative characters. The varieties / accessions varied remarkably in the vegetative characters like tree height, tree habit, leaf shape, leaf margin and leaf tip. Leaf length, leaf width and petiole length varied significantly between the varieties. The varieties / accessions varied widely with respect to the floral characters like position of inflorescence, shape, length, colour and density of flowers and season and regularity of flowering. The percentage of hermaphrodite flowers ranged from 8.4 (Velutha Muvandan) to 96.0 (Eara Local). The fruit characters like shape, presence of basal cavity, beak type, sinus type, presence of groove, type and slope of shoulders and apex exhibited by the varieties / accessions showed remarkable variation. High variability in fruit length, breadth, thickness, weight and volume could also be observed among the varieties / accessions. Muthalamookan recorded the highest length, breadth, thickness, weight and volume of fruits and Puliyan manga recorded the lowest values. Fruit weight ranged from 37.5 g to 826.0 g. Skin characters like colour, thickness, texture and weight also showed high variability. Percentage contribution of skin weight to the fruit weight varied from 8.4 (Ambalathara Local) to 37.7 (Puliyan). The different varieties varied considerably in the various flesh characters like weight, texture, adherence of skin to pulp, fibre content and colour. Pulp weight ranged from 14.8 g to 676.0g. Stone characters showed wide variation among the accessions. Quality characters of fruits varied widely among the accessions. Titrable acidity ranged from 0.12 per cent (Nedungolan) to 4.03 per cent (Eara Local). Ascorbic acid content ranged from 3.08 (Neendakara manga) to 119.05 (Natumav Type-2) mg / 100g. The total carotenoid content varied from 0.21 (Natumav Type-4) to 7.97 mg / 100g (Karpoora Varikka). The TSS of ripe fruits ranged from 8.77 to 25.71 0 Brix. Total sugar content ranged from 2.0 (Natumav Type-4) to 22.2 per cent (Neenda Karpooram). The reducing sugar content ranged from 0.9 per cent (Kalluketty) to 6.1 per cent (Perakka manga). Non- reducing sugar content varied from 0.81 per cent (Natumav Type-4)to 16.8 (Neenda Karpooram ). The crude fibre content in fruit pulp ranged from 0.4 per cent (Nedungolan) to 2.92 per cent (Natumav Type-3). Perakka manga was rated as the best in organoleptic evaluation. The accessions, Pulichi, Natumav Type- 2, Natumav Type-5, Kalluketty, Vellari Type-1and Kalkanda Vellari can be recommended as outstanding in pickling qualities. Of the table types, Nedungolan, Perakka manga, Muthalamookkan, Vellari Type-2, Karpooram manga and Neenda Karpooram can be recommended as superior with respect to important economic characters like fruit weight, pulp content and eating quality. Among the dual types, Kotookonam Varikka, Velutha Muvandan, Karpoora Varikka, Ambalathara Local and Kizhakkan Thali can be recommended as excellent in overall acceptability. DNA was extracted from young leaves using CTAB method (Dellaporta et al., 1983) with slight modification (Anuj et al., 2004). A total of 157 RAPDs (average of 3.74 bands per primer) were generated on PCR amplification using 42 decamer primers, of which 96.18 per cent (151 bands) were polymorphic. This accounts to an average of 3.6 bands per primer. Of these, ten primers yielded 92 scorable bands with an average of 9.2 bands per primer. The number of bands resolved per amplification varied from six to fourteen. A genetic similarity matrix was constructed using the Jaccard’s coefficient method. The pair wise similarity coefficient values ranged from 0.217 to 0.833. In the dendrogram, the thirty accessions subjected to RAPD analysis, were observed to group into seven clusters. The largest cluster contained 20 accessions. Four table varieties, Kappa manga, Mylapore manga, Neenda Karpooram and Kandiyoor Local were grouped together. All these were soft fleshed. Muthalamookan and Kolambi manga clustered together. Puliyan, Perakka manga, Kalluketty and Champa Varikka formed four separate clusters. Similarity assessment based on morphological and quality characters suggested that there was very high diversity among the traditional mango varieties. The pair wise similarity coefficient values varied between 0.042 and 0.708. The clustering pattern based on RAPD analysis was not strictly in accordance with that based on morphological and quality characters.
Characterization of bud necrosis virus infecting tomato
(Department of Plant Pathology, College of Agriculture, Vellayani, 2011) Simi, S; Umamaheswaran, K
Studies were conducted to characterize the tospovirus causing the bud necrosis disease of tomato in Kerala. The characteristic symptoms observed were, necrotic ring spots on leaves and severe necrosis, death of the emerging buds, stem necrosis and concentric yellow colored rings on fruits. Host range studies were conducted and the virus was found to infect members of family Chenopodiaceae, Solanaceae, Fabaceae, and Cucurbitaceae. The virus was efficiently transmitted by mechanical means using 0.01 M phosphate buffer (pH 7.2) containing 0.1 per cent 2-mercaptoethanol. No seed transmission was recorded. However successful graft transmission was observed. The virus recorded a DEP in the range of 10-3 to 10- 4 , TIP of 50 oC to 55 oC, and LIV of 8 h at room temperature (28±2oC) and 24 h at 80C. The carbohydrate levels in inoculated plants were lower compared to the uninoculated tomato plants. Similarly the content of chlorophyll a, b and total chlorophyll were also lower in inoculated tomato plants. The phenol content was found to be more in inoculated plants. There was an increase in protein content in inoculated plants compared to the healthy plants. In case of inoculated plants the activity of the defense related enzymes were higher than the control plants. Protein profile of tospovirus infected tomato plants using SDS - PAGE showed three extra novel proteins with molecular weights of 28, 15 and 12 kDa respectively. Isozyme analysis of PPO produced three isoforms in both healthy and inoculated plants with relative mobility (Rm) values of 0.60 and 0.77. The activity of the two isoforms were more in the inoculated plants. The virus causing bud necrosis disease in tomato was confirmed as tospo virus by serological analysis such as ELISA and DIBA. The virus isolate showed close relationship with WSMV. The virus was also detected using PCR and an amplicon of size 800 bp was obtained using primer specific to tospovirus. The meristem from the infected tomato plants were regenerated into plantlets and were tested for the presence of the virus by subjecting it to DAC- ELISA. The absorbance of the plantlet regenerated from healthy and infected meristem were found to be 0.13 and 0.12 respectively which was on par with the healthy field sample but much lower than that of the infected field sample which was used as the positive control which recorded an absorbance of 0.81.
Evaluation of propagation techniques and rootstock studies of mango (Mangifera indica L.)
(Department of Pomology and Floriculture College of Agriculture, Vellayani, 2019) Reshma, U R; Simi, S
Fertigation studies in banana (Musa acuminata AAA) cv. red banana
(Department of Fruit Science, College of Agriculture Vellayani,, 2025-01-15) Divya Hari.; Simi, S
The present study entitled ‘Fertigation studies in banana (Musa acuminata AAA) cv. Red banana was carried out at the Department of Fruit Science, College of Agriculture, Vellayani, Thiruvanathapuram, during the period 2020-2023. Red banana or Chenkadali (fruit locally known as kappa pazham) is one of the most relished and highly priced varieties of Kerala rich in antioxidants, beta carotene, vitamin C and vitamin B6. For increased yield and productivity, standardization of nutrient requirement and fertigation schedule is pertinent to ensure steady supply of nutrients and water at the right growth phases. Considering these aspects, the present study was proposed to standardize the nutrient levels and fertigation schedule for yield improvement in red banana under fertigation system. The experiment was conducted in combinations of four different fertigation levels (F) and three levels of split applications of fertilizers (S), laid out in randomized block design replicated thrice with 12 plants per plot at a spacing of 2.1 x 2.1 m. Fertigation treatments were fixed based on the soil test-based N and K recommendation. The fertigation levels were F1 – 60 % recommended dose (RD) of N and K, F2 – 80 % RD of N and K, F3– 100 % RD of N and K, F4 – 120 % RD of N and K and the split application levels include S1– equal splits of N and K at weekly intervals upto 12 months, S2 – equal splits of N and K at fortnightly intervals upto 12 months, S3 – split application of N and K according to the phenological growth stage from 5th to 12th week (30% N and 10% K), 13th to 25th week (35% N and 10% K), 26th to 37th week (20% N and 30% K), 38th to 49th week (15% N and 25% K), 50th to 52nd week (25% K), control KAU POP (200: 200: 400 g NPK plant-1 year-1), soil application of nutrients with conventional land management and drip irrigation). Organic manure (10 kg FYM plant 1) and P (200 g plant-1) was given uniformly to all treatments as basal. The biometric parameters recorded showed that nutrient level at 120% RDF of N and K (F4) recorded the highest values for plant height, pseudo stem girth, leaf number, total functional leaf area and leaf area index. Lesser number of days to shooting, shoot to harvest, crop duration and phyllocron was recorded for 80% RDF of N and K (F2). Fertigation schedule according to the growth stage of the crop (S3) 156 recorded higher plant height, pseudo stem girth, leaf number, total functional leaf area and leaf area index, it also recorded earliness in days to shooting, shoot to harvest and crop duration. F2S3 interaction recorded earliness in days to shooting, shoot to harvest and crop duration which was on par with F3S3 for days to shooting. The yield parameters including bunch weight and fingers per bunch was observed to be the highest with application of 80 % RDF of N and K (F2) which was on par with F3 and F4. Finger length, finger girth and finger weight were the highest for F3 which was on par with F4, yield (t/ha) was the highest for F2 which was on par with F3 and F4. Length of bunch, bunch weight, fingers per bunch, fingers per hand, finger length, girth and weight were observed to be higher with application of fertilizers according to the growth stage of the crop (S3). F2S3 recorded the highest length of bunch, hands per bunch, fingers per bunch and fingers per hand. F3S3 recorded the highest yield and B: C ratio and was on par with F2S3, F4S1, F4S3, F3S1. The quality parameters of fruit including TSS, total sugar, reducing sugar, non reducing sugar and carotenoid content were the highest in F3 which was on par with F2. Total sugar, non-and reducing sugar recorded highest values for S3 which was on par with S1. F2S3 recorded the highest total sugar and reducing sugar which was on par with F3S3. The nutrient analysis of fruit at harvest stage recorded the highest N content on fruits for F4 and N and P content for S3. The interaction of fertilizer level and split application recorded the highest N and K content for F4S3 and F3S1 respectively. The highest NPK content on index leaf was recorded in nutrient levels F3 and F4 and in split application, S3. The interaction effect recorded higher N content for F3S3 and K content for F3S1. The soil analysis after the experiment recorded higher EC and organic carbon content for F4 and F3 respectively. The split application of fertilizers according to growth stages of the crop (S3) recorded higher organic carbon content. Interaction effect of nutrient level and fertigation schedule recorded higher electrical conductivity for F4S3 and organic carbon content for F3S1. The N and K content of soil recorded higher values for F3 and F4 respectively. Interaction effect of nutrient level and split application 157 of fertilizers record higher N and K content for F4S3. Among the micronutrients, Fe content was found to be maximum in F1 at fertilizer level and F2S1 interaction. Application of 80% RD of N and K in split doses according to the growth stage of the crop exhibited superior performances across biometric, yield and quality parameters in red banana under fertigation system with high B: C ratio. The treatment could save 20 % of fertilizers, reduced the crop duration by 100 days, increased the yield by 10.8% when compared to the control.
Molecular characterization of banana (Musa AAB plantain subgroup) clones
(Department of Pomology and Floriculture, College of Agriculture, Vellayani, 2001) Simi, S; Rajmohan, K
Attempts were made for characterizing eleven banana (Musa AAB Plantain subgroup) clones at molecular level during January 2000 to October 2001 at the Department of Pomology and Floriculture and the Plant Molecular Biology and Biotechnology Centre, College of Agriculture, Vellayani. Tissues from fully unfurled leaves of the clones, were used for isolating DNA, using modified Walbot's method. Storage of leaves at -SYC did not affect either the DNA yield or purity ratio. Gel elctrophoresis using agarose concentrations of 0.09 per cent and 1.4 per cent were the best for visualizing the genomic DNA and RAPD pattern, respectively. The best voltage level was 75 V. TBE buffer could produce better separation of bands compared to TAE buffer. Twenty nanogram of DNA, 200 IlM each of dNTPs, 0.6 units Taq DNA polymerase and 5 pM primer in presence of the assay buffer gave good PCR amplification results. The programme consisted of an initial denaturation at 95°C for 3.0 minutes, followed by 45 cycles of denaturation at 95°C for 1.0 minute, annealing at 36°C for 1.0 minute 30 seconds and extension at 72°C for 2.0 minutes. The synthesis step of the final cycle was extended further by 6.0 minutes. The products of .ampl ification were kept at 4.0°C until attended. One hundred and six RAPDs were generated when PCR amplification was carried out using forty decamer primers (Operon Inc., CA, USA) of kit A and kit B. Of these, 100 bands were polymorphic which accounted to an average of 2.5 polymorphic bands per primer. Eight primers (OPA-OI, OPA-03, OPA-13, OPB-OI, OPB-06, OPB-lO, OPB-12 and OPB-IS) produced reproducible banding patterns on at least two runs. These primers yielded 42 scorable bands with an average of 5.25 bands per primer. The amplification products ranged in size from 400 to 1500 bp. The number of bands resolved per amplification was primer dependent and varied from a minimum of three to a maximum of nine. Reproducible bands were scored for their presence (+) or absence (-) for all the plantain clones studied. A genetic similarity matrix was constructed u~ng the Jaccard's coeffecient method. The pairwise coefficient values varied between 0.3333 and 0.9355. The least similarity coefficient values were those of Zanzibar with Changazhikodan and Manjeri Nendran (0.3333). The highest value for similarity index was obtained for Koonoor Ethan - Quintal Banana pair (0.9355), followed by Manjeri Nendran - Myndoli pair (0.8889). The next value was for the Kaliethan - Koonoor Ethan pair (0.8529). Based on the similarity coefficients, distances between the clones were computed using SYSTA T software package. The distance was the least between Koonoor Ethan and Quintal Banana (0.042), followed by Manjeri Nendran and Myndoli (0.06). Zanzibar and Mysore Ethan showed the greatest distance (0.349), followed by Mysore Ethan and Padalamurian (0.167). In the dendrogram constructed by the nearest neighbour (single-link) method (Krzanowski, 1988), all the eleven plantain clones were found grouped under five clusters. Attu Nendran, Changanasseri Nendran, Changazhikodan, Kaliethan, Koonoor Ethan and Quintal Banana formed the largest cluster. Manjeri Nendran and Myndoli formed the second cluster. Padalamurian, Mysore Ethan and Zanzibar formed three separate clusters. Zanzibar, belonging to 'Horn Plantain', was different from the rest of the clones. Quintal Banana and Myndoli, which were considered to be identical, got grouped under two different clusters.
Performance evaluation of ecotypes of banana (Musa AAB plantain subgroup)
(Department of Pomology and Floriculture, College of Agriculture, Vellayani, 2017) Annjoe Joseph, V; Simi, S
Varietal evaluation of guava(Psidium guajava L.) for urban horticulture
(Department of Fruit Science, College of Agriculture, Vellayani, 2025) Swetha, V; Simi, S
The present research work entitled “Varietal evaluation of guava (Psidium guajava L.) for urban horticulture” was conducted at the Department of Fruit Science, College of Agriculture, Vellayani, from 2023 November to 2024 October. The study was under taken to evaluate the growth and yield response of planting materials of guava to different type and size of containers and to evaluate the growth response of different varieties of guava in containers. The experiment 1 entitled “Performance evaluation of guava (Psidium guajava L.) in containers” was laid out in Completely Randomized Design (CRD) with 18 treatments and 3 replications using the guava variety Arka Kiran. The treatments included two container types (C1 - Plastic container and C2 - Air-pot), three container sizes (V1 – 40 L, V2 – 60 L and V3 – 80 L) and three different planting materials (P1 - Air layers, P2 - Rooted cuttings and P3 - Grafts). The medium of planting consisted of soil, coir pith and farm yard manure in 1 : 1 : 1 ratio across all treatment. Twelve- month-old potted plants were subjected to the study. Plants in plastic containers (C1), registered significantly taller growth with greater plant spread, primary stem girth, number of leaves per plant (at 15, 18, and 21 MAP), stem girth (at 15 and 18 MAP), root dry weight, shoot dry weight, and leaf area (at 21 MAP) compared to those in airpots. Meanwhile, plants in airpots exhibited earlier flowering, shorter duration from flowering to harvest and longer flowering duration. They also produced greater number of fruits and higher fruit weight, length, diameter and fruit yield. Among different container volumes, 80 L (V3) had the tallest plants with the highest plant spread, stem girth and primary stem girth and the highest number of leaves per plant (15 MAP, 18 MAP and 21 MAP). In addition, they exhibited earliness in flowering and harvest, highest flowering duration, fruit weight, length, diameter, number of fruits and fruit yield. Root dry weight, shoot dry weight (21 MAP) and leaf area were also the highest in V3. 168 Among the different planting materials, air layers produced taller plants with greater plant spread (at 15, 18, and 21 MAP), number of leaves per plant, leaf area and root-to-shoot ratio (at 21 MAP). In addition, they exhibited early flowering, longest flowering duration and the shortest number of days from flowering to harvest. The number of fruits, fruit weight, fruit length, diameter and fruit yield were also observed to be the highest in air layers. Grafts (P3) recorded the highest values for stem girth, primary branch girth, root dry weight and shoot dry weight. The fruits were analysed for quality parameters, including TSS, total sugar, reducing sugar, ascorbic acid, total antioxidant activity and total carotenoids. Container size, type, and planting material showed a significant difference in ascorbic acid and carotenoid content, whereas all other parameters were non-significant. Ascorbic acid and carotenoid content were higher in airpots. In terms of container volume, the 80 L containers showed higher ascorbic acid(227.67 mg 100g-1) and carotenoid levels (0.67 mg 100g-1) , while, among planting materials, air-layered plants had the highest values. Leaf tissue was analysed for physiological and biochemical parameters viz., chlorophyll content, total carotenoids, total reducing sugars and total soluble proteins at 18 MAP. Container type and planting material did not show any significant effect on these parameters, while 80 L container volume showed significantly higher total soluble proteins compared to 40 and 60 litres. The two factor interaction between container type and size (C x V), showed that 80 L plastic containers (C1V3) recorded significantly higher plant spread (E-W and N-S), stem girth, leaves per plant, leaf area and root dry weight. The shoot dry weight was higher in both plastic container and air-pots with 80 L (C1V3 and C2V3). Air-pots with 80 L (C2V3), exhibited early flowering with more fruits per plant, enhanced flowering duration, earlier flowering to harvest and the highest fruit weight, length, diameter and fruit yield. Interaction between container type and planting material (C x P) also confirms similar results in air-pots with air layers (C2P1). Root : shoot ratio was the highest in air-pots with grafted plants (C2P3). The two factor interaction between container size and planting material (V x P) showed that air layers grown in 80 L containers (V3P1) outperformed other combinations with respect to plant height, plant 169 spread, leaves per plant, leaf area, number of fruits, flowering duration, days to flowering, days from flowering to harvest, fruit weight, length, diameter and fruit yield. Shoot dry weight, stem girth and primary stem girth were the highest in 80 L with graft (V3P3). In three factor interaction, 80 L plastic containers with graft (C1V3P3) showed higher root dry weight and shoot dry weight while plant height and leaf area were the highest for air layers in 80 L plastic container (C1V3P1). The least number of days to flowering and days from flowering to harvest were observed in 80 L airpots with air layers (C2V3P1) they also produced the highest number of leaves and fruits, as well as the greatest fruit weight, length, diameter and fruit yield. Another notable feature observed in the study is the presence of root coiling in plastic containers of all sizes (40, 60, and 80 L), regardless of the type of planting material. In contrast, root coiling was absent in airpots of all container sizes. This study underscores the importance of selecting appropriate container types, sizes, and planting materials for successful guava cultivation in containers. Airpots outperformed plastic containers by enhancing reproductive traits like early flowering, extended flowering duration, and superior fruit yield and quality. Larger containers (80 L) showed the best results across growth, fruit yield and biochemical parameters, including ascorbic acid and carotenoids. Among planting materials, air layers excelled in vegetative growth, earliness in flowering, and fruit quality, establishing 80 L airpots with air layers as the optimal choice for container-based guava cultivation. The experiment 2 entitled “Varietal evaluation of guava (Psidium guajava L.) for urban horticulture” was laid out in Completely Randomized Design (CRD) with 5 treatments and 3 replications. The treatments included five varieties of air layered guava: T1-Allahabad Safeda, T2-Lucknow 49, T3-Arka Kiran, T4-Arka Rashmi and T5- Arka Mridula. (Note: The best container type, container size and planting material (Airpots 80 L air layers) was selected from the result of first year observations of the experiment entitled “Performance evaluation of guava (Psidium guajava L.) in container and used in this experiment). T5-Arka Mridula registered the highest plant 170 height, primary and the secondary stem girth, while early flowering with highest number of flowers was registered in T4-Arka Rashmi. Leaf tissue was analysed for physiological and biochemical parameters viz., chlorophyll content, total carotenoids, total reducing sugars and total soluble proteins at 6 MAP. Total chlorophyll (0.98 mg 100 g -1), reducing sugar (1.84%) and carotenoid content(0.70 mg 100 g -1) were the highest in T5-Arka Mridula and total soluble protein was the highest in T1-Allahabad Safeda. This study emphases the importance of the growth response of different varieties of guava in containers. Among vegetative parameters, plant height, primary and secondary stem girth were the highest in Arka Mridula which was reflected in physiological and biochemical parameters like chlorophyll, reducing sugar and carotenoid contents that gave the highest values. However, in plant spread and flowering parameters like days to flowering and number of flowers the highest values were in Arka Rashmi. Plants with a compact canopy and good reproductive parameters are ideal for container growing. Thus, the present study unveils the suitability of Arka Rashmi for container growing of guava.