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Open Access
Calibration and validation of ceres rice crop simulation model
(Department of Agronomy College of Agriculture, Vellayani, 2018) Anju, V S; KAU; Girija Devi, L
The project entitled ‘Calibration and validation of CERES-Rice crop simulation model’ was conducted in the Department of Agronomy, College of Agriculture, Vellayani from 2016 to 2018 with the objectives to calibrate and validate CERES-Rice model to generate the genetic coefficients of the rice variety Prathyasa, to study the crop- weather relationship and to quantify the yield gap of the variety by running simulations. The field experiment was conducted at Upanniyoor Panchayat in farmer’s field for four seasons (Virippu 2016 and 2017 and Mundakan 2016 and 2017) and it was laid out in randomized block design. The treatments consisted of five dates of sowing each in Virippu (D1 - May 31, D2 –June 15, D3 –June 30, D4 –July 15 and D5 – July 30) and five dates of sowing each in Mundakan (D1 -Oct 14 / Sept 26, D2 – Oct 30 /Oct 10, D3 – Nov 14/ Oct 25, D4 –Nov 30/Nov 9 and D5 – Dec 14/Nov 24). The sowing dates in Mundakan seasons of 2016 and 2017 varied due to the delayed onset of rainfall in 2016. The plot size was 5 x 4 m2 with three replications. Routine observations on height, leaf area, dry matter production (DMP), number of tillers, panicles, spikelets per panicle, filled grains per panicle, 1000 grain weight, straw yield and grain yield were recorded apart from phenological observations. Soil analysis was conducted before and after the experiment. The soil and crop data collected from the experimental field and weather data from the Department of Agrometeorolgy were used as inputs for running the model. Study on phenology revealed that the crop duration decreased from 111 to 100 and 117 to 107 days respectively in Virippu 2016 and 2017. A similar decreasing trend was observed in Mundakan 2016, but in Mundakan 2017, it increased from 114 to 117 days in early sowing and decreased drastically from 117 to 105 days in delayed sowing. The height of the plant was found varying at different stages, D1 produced the tallest plants at harvest in Virippu seasons of both the years, while it was the highest in D3 in Mundakan 2016 at different stages and D5 in Mundakan 2017. The number of tillers was the highest in D2 and D1 respectively in Virippu in both the years and D2 and D1 respectively in Mundakan 2016 and 2017. The DMP was the highest in D2 and D1 respectively in Virippu and Mundakan 2016 and 2017. The grain yield was the highest in D2 in both the seasons in 2016 and D1 in both the seasons in 2017. The yield attributes such as productive tillers m-2 was the highest in D2 in both the seasons in 2016 and D1 in both seasons in 2017. The number of spikelets per panicle was the highest in D1 during Virippu 2016 and 2017 and Mundakan 2017 and D2 in Mundakan 2016. D1 in Virippu 2017 was on par with D2, and D2 in Mundakan 2016 was on par with D1. The number of filled grains per panicle was higher in D1 in Virippu 2016 and Mundakan 2017, while D2 recorded higher filled grains per panicle in Virippu 2017 and Mundakan 2016. D1 in Virippu 2016 was on par with D2 and D2 in Mundakan 2016 was on par with D1. The harvest index (HI) was higher in D1 in Virippu 2016 and 2017 and Mundakan 2017, while D2 recorded higher HI in Mundakan 2016. D1 in Virippu 2016 was on par with D2 and D5, and D1 in Virippu 2017 was on par with D2. In Mundakan season, D2 was on par with D1 and D5 in 2016 and D1 was on par with D2 in 2017. In Virippu and Mundakan 2016, N uptake was the highest in D1 while P and K uptake were the highest in D2, whereas in Virippu and Mundakan 2017, N, P and K uptake were the highest in D1. The organic carbon content of the soil was found influenced only after Virippu 2016 with D5 recording the highest value. In the case of available N, P and K status of the soil, only the N status was found affected and that was only after Mundakan 2017 with D2 recording the highest value. Crop weather relationship was studied by computing the different heat units such as Growing degree days (GDD), Heliothermal units (HTU), Photothermal units (PTU) and Heat unit efficiency (HUE) at different stages such as sowing to active tillering (P1), active tillering to panicle initiation (P2), panicle initiation to booting (P3), booting to heading (P4), heading to 50% flowering (P5), 50% flowering to physiological maturity (P6), vegetative stage (P7), reproductive stage (P8) and ripening stage (P9). These heat units computed were the highest in D1 and showed positive correlation with yield for GDD at P1, HTU at P5 and P6, PTU at P1 in Virippu, while in Mundakan positive correlation was obtained with GDD at P1 and P7, HTU at P2, PTU at P1 and P7. Negative correlation was obtained with GDD at P3, P8 and P9 and PTU at P4, P8 and P9 in Virippu and with HTU at P2 and P3 and PTU at P6 and P9 in Mundakan. The correlation between yield and yield attributes with weather parameters revealed positive correlation for minimum temperature at P3, P4 and P8, RH I & RH II at P1 and P7, BSS at P2, P3, P4 and P6, rainfall and rainy days at P1 and P7, pan evaporation at P6, P8 and P9 and wind speed at P6 and P9 in Virippu season. Negative correlation was observed with minimum temperature, pan evaporation and wind velocity at P1, rainfall at P3, P4, P6, P8 and P9, rainy days at P6, P8 and P9, RH I at P6, P8 and P9, RHII at P5, P6 and P9 in Virippu season. In Mundakan season positive correlation was obtained with maximum temperature from P1 to P9 except P6, RH I at P2, P4, P5, P7, P8 and P9 and rainy days at P1 and negative correlation with maximum temperature at P1, P2 and P6, minimum temperature at P6, BSS at P2, rainfall at P6, pan evaporation at P3, P5, P6, P7, P8 and P9. The genetic coefficients for the variety Prathyasa was generated by calibrating the CERES-Rice model by using the data of Virippu rice 2016 and validated by using the data of Mundakan 2016, Virippu and Mundakan 2017 respectively and the genetic coefficients generated were P1-720, P2R-33.7, P5-21.3, P2O-12, G1-38.7, G2-0.028, G3-1, G4-1 respectively. Model simulated results showed that there was close association between observed and simulated yield and the error percentage varied from -16.90 to 16.55 for Virippu 2016 and from -1.26 to 64.77 in Virippu 2017. In Mundakan, error per cent ranged from -13.43 to 16.63 in 2016 and from -11.09 to 12.58 in 2017. The error percentage for panicle initiation day varied from 1.96 to 18.37 in Virippu 2016, while it varied from -5.88 to 10 in Virippu 2017 and for Mundakan it varied from -8.16 to 0 in 2016 and from -8 to 1.96 in 2017. Similarly the error percentage for anthesis day varied from 8.54 to 11.25 and 4.88 to 9.88 in Virippu 2016 and 2017 and from 4.88 to 9.88 and 3.66 to 8.43 in 2016 and Mundakan 2017. The error percentage of physiological maturity day varied from -1.96 to 18 in Virippu 2016, while it deviated from -7.84 to 0.99 in Virippu 2017. During Mundakan season, error percentage ranged from -1.98 to 6.54 in 2016 and from -2.91 to 4.81 in 2017. Regression equations for grain yield were developed for certain phenological stages in Virippu and Mundakan from highly correlated weather parameters. The yield gap quantification revealed that the highest total and sowing yield gaps were in delayed sowing (D5), management yield gap in early sowing(D1), and the lowest in D3 and D4 (delayed sowing) and D2 (early sowing) respectively for the same parameters. Thus, the study enabled to generate the genetic coefficients of variety ‘Prathyasa’ and simulated the grain yield and panicle initiation, anthesis and physiological maturity days with minimum error percentage. The study also helped to quantify various yield gaps such as total, management and sowing gaps due to different dates of sowing, from the potential yield generated by the model along with the attainable and actual yield data supplied from the field experiment and farmers’ field. The various correlations worked out between yield, weather parameters and heat units provided an insight into the crop weather relationship. Finally, and the foremost implication of the study is that delayed sowing reduces the yield considerably in rice crop in both the seasons irrespective of other factors.
Open Access
Hybridization using promising second generation inbred and molecular characterization of a the third generation inbreds of WCT coconut
(Department of Plant Breeding and Genetics, College of Horticulture, Vellanikkara, 2018) Hassain, N; KAU; Sujatha, R
The research project entitled “Hybridization using promising second generation inbred and molecular characterization of the third generation inbreds of WCT coconut (Cocos nucifera L.)” was carried out in the Department of Plant Breeding & Genetics, College of Agriculture, Padannakkad during the year 2016-2018. The major objectives of this study include development of D x T hybrids using promising palms in second generation (S2) inbreds of West Coast Tall (WCT) as male parent and Malayan Yellow Dwarf (MYD) as female parent and characterization of third generation (S3) inbred seedlings of superior S2 palms of WCT using RAPD analysis. For hybridisation, the male parent was selected from the superior inbred family based on the reports on morphological evaluation and estimation of inbreeding depression during the period 2013-2015 (Chethana, 2016). The family IIIS2-1 showed lowest inbreeding depression for yield related traits among 12 families followed by VS2-2. The palm 313 (IIIS2-1) and 225 (VS2-2) were selected as male parents. Superior MYD palm to be used as the female parent was selected from among the MYD palms available at CoA, Padannakkad based on the general features of mother palm selection (Nair et al., 2008). Observations were recorded from these parental palms which included 24 morphological characters. The male parents showed inbreeding depression for several vegetative characters such as stem girth, functional leaves etc and reproductive characters such as number of female flowers per inflorescence, setting percent and nut yield per palm per year, compared to WCT. The results showed that inbreeding depression for these characters was more in palm 313 (developed by selfing) than palm 225 (developed by sibmating). Total five nuts were harvested from MYD (two nuts by using pollen from palm 313 and three nuts using pollen from palm 225) during May 2018 and were sown in the nursery. Molecular characterization of the 15nos of S3 inbred seedlings of IIIS2 family planted in the field in replicated plots were done using RAPD. Genomic DNA was isolated from 15 seedlings of IIIS3 family among which 10 were produced by selfing the S2 palms (IIIS3-1) and 5 were produced by sibmating the S2 palms (IIIS3-2) along with COD, CGD and WCT. After DNA isolation, samples were subjected to RAPD analysis using 10 decamer primers namely OPAU02, OPBA3, OPAW14, OPAW19, OPAW12, OPAW13, OPAW13, OPAW09, OPAU03, OPAW08 and OPAW15 selected based on screening 30 primers. Using primer OPAW08, a band of size of ~400bp was specifically found in inbreds alone while it was absent in dwarfs and WCT seedlings. In OPAU 03 primer, band size of ~1200bp was absent in WCT but present in all inbreds and CGD. The sibmated inbred NL1 showed a distict pattern when amplified with OPAW 09 compared to all other inbreds. The primer produced a specific band of size ~1050bp only in the sibmated inbred CL1 and was absent in all other samples. Amplification with OPAW19 primer produced a banding pattern in which it mainly distinguished CGD from all other seedlings where there were only two bands while others were having six bands. Primer OPAU 02 produced two unique amplicons: 1100bp present in selfed inbred I1M1 TH2 and MYD; 1000bp present in COD and MYD. Genetic similarity among the 15 IIIS3 seedlings, CGD, COD, MYD and WCT was estimated by using of software DARwin (Darwin 6.Ink). The dendrogram indicated three major clusters in which the grouping of several inbreds along with WCT, COD and CGD may be an indication supporting the hypothesis that the dwarfs might have been originated from the talls during the course of evolution followed by selection. The two dwarfs present in the group are COD and CGD which are from Chavakkad area in Kerala and WCT is the most common cultivar of Kerala. As a future line of study, further evaluation of these S3 inbreds regarding the flowering time and yield characters has to be carried out to find out the genetic potential of these inbreds as breeding lines for producing superior hybrids. The seedlings to be emerged from the hybrid nuts produced in the present study, though limited in number, needs to be evaluated for important traits and the hybridisation programme using superior palms in S2 generation needs to be continued for production of more number of hybrid nuts.
Open Access
Effect of seed treatment on growth, seed yield and quality in Okra (Abelmoschus esculentus L. Moench
(Department of Seed Science and Technology College of Horticulture, Vellanikkara, 2018) Adersh, S; KAU; Dijee Bastian
The research work 'Effect of seed treatments on growth, seed yield and quality in okra (Abelmoschus esculentus L. Moench)', was conducted in the Department of Seed Science and Technology, College of Horticulture, Vellanikkara, during 2017-18 with an objective to find the effect of seed treatmentwith growth regulators on growth, seed yield and quality in okra and to delineate their effect on seed quality and longevity. Two separate experiments were conducted. Freshly harvested okra seeds of variety Arka Anamika, were treated with different concentrations of growth regulators namely GA3, IAA, NAA, Cycocel, Maleic hydrazide and Thiourea for two different time period (12 hours and 24 hours) and used to conduct the field experiment (Experiment 1) immediately. The experiment uses the treated seeds was laid out in Randomised Block Design with three replication and twenty five treatments including control. Observations on growth and yield parameters were recorded at appropriate stages. The results revealed that seed treatment with different plant growth regulators exhibited significant differences for all the characters studied. Growth characters like plant height, internode length, number of fruits per plant and seed yield per plant were found to be high in T24 (Thiourea 1000 ppm for 24 hours), while T16 (CCC at 150 ppm for 24 hours) and T14 (CCC at l50ppm for 12 hours) registered higher values for nodes per plant and branches per plant respectively. Among the treatments T3 (GA3 50 ppm for 24 hours) flowered early at 36.26 days. Higher values for fruit length and seeds per fruit were recorded in GA3 100 ppm for 24 hours (T4) and fruit weight was found to be higher in NAA 100 ppm for 24 hours (Tu). The seeds obtained under the field experiment were used to conduct the seed storage studies (Experiment II). The seeds from each treatment of experiment I were dried separately to a moisture content of less than 8 per cent and packed in 700G polythene covers and sealed. Seeds were stored under ambient conditions and seed quality parameters evaluated at monthly intervals for a period of seven months. Experiment II was laid out following a Completely Randomized Design (CRD) with twenty five treatments (To to TZ5) as in experiment I and three replications. Significant differences existed among the treatments for all seed quality parameters studied except time taken for 50% germination, seed moisture and seed microflora. It was clearly evident from the storage study that, as storage period increases the seed quality decreases irrespective of the treatments. In case of germination, all treatments including the control maintained the Minimum Seed Certification Standard (MSCS) of 65 percent up to fifth month of storage. At the end of the storage period (7 MAS) only two treatments (T11-NAA 50ppm for 24 hours and T3-GA3 50ppm for 24 hours) retained MSCS (65%). Vigour index I and II had higher values in Til which was statistically on par with TIZ, TlO, T3 and T4. Seed quality parameters such as germination, vigour indices and seedling dry weight decreased with the advancement of storage period, whereas EC of seed leachate, germination time, time taken for 50% germination increases over the storage period. The effect of growth regulators on seed microflora was found to be non-significant at the start and the end of the storage period. But the per cent of seed infection by seed microflora increased at the end of storage period, irrespective of the treatments. Ranking of characters in experiment I along with germination percent and vigour index I of experiment II was undertaken to identify the superior treatments. Based on the total score obtained GA3 at 50 ppm for 24 hours (T3) was adjudged as the best treatment followed by NAA at 50 ppm for 24 hours (T11). Hence it is concluded that soaking seeds with GA3 at 50 ppm and NAA at 50 ppm effectively enhances the growth, fruit and seed yield, seed quality and longevity in okra.
Open Access
Breeding for shattering resistance in rice (Oryza sativa L.)
(Department of Plant Breeding and Genetics, College of Horticulture, Vellanikkara, 2018) Anju, M Job; KAU; Biju, S
The research work 'Breeding for shattering resistance in rice (Oryza sativa L.)' was conducted in the Department of Plant Breeding and Genetics, College of Horticulture (COH), Vellanikkara, during the academic year 2017-2018. The research work was mainly divided into three experiments. Experiment 1 consisted of screening of rice genotypes for shattering resistance which was conducted at Agricultural Research Station (ARS), Mannuthy. After screening, four selected shattering resistant rice genotypes were crossed in Line x Tester pattern with three shattering prone high yielding varieties in experiment 2. In experiment 3 progenies were evaluated along with parents for shattering resistance. Shattering was measured based on Induced Random Impact method using a force gauge apparatus. Wide variability was found to exist among twenty five genotypes for yield and most yield attributes studied indicating ample scope for improvement through selection. High heritability coupled with high genetic advance as per cent of mean indicating the influence of additive gene action in the expression of trait were observed for days to fifty per cent flowering, flag leaf width, flag leaf length, panicle per plant, seed yield per plant and shattering per cent. Substantial improvement in the expression of these characters over base population can be expected through simple selection. Tillers per plant showed moderate heritability along with high genetic gain implying influence of both additive and non additive gene action in the expression of these characters. Improvement of these traits could be attained by following recurrent or reciprocal recurrent selection to exploit both additive and non-additive genetic components. Seed yield per plant recorded high significant correlation with number of tillers per plant, flag leaf width, number of panicles per plant and seeds per panicle and significant correlation with test weight. Shattering per cent recorded a high significant inter correlation with panicle length and significant inter correlation with kernel length. High estimates of general combining ability (OCA) over specific combining ability (SCA) is indicative of preponderance of additive gene action and it was evident in the case of days to maturity, flag leaf width, seeds per panicle and kernel width. Prevalence of non-additive gene action i.e., dominance and epistatic gene action in trait expression indicated by high SCA over OCA was registered for the remaining characters. When parents were evaluated on the basis of mean performance, it was evident that for seed yield per plant L2, L3 and T1 recorded a high response. The response recorded for panicle length and shattering per cent were exactly similar. When all the fourteen characters for the seven parents considered together, L2, L3 and T2 represented as best parents for yield and yield attributes and T1 recorded to be a moderate response. Evaluation of hybrids based on mean performance revealed that out of the twelve hybrids, H1, H2, H3, H4, H6 and H11 recorded a high response towards reduced shattering and H5 reported moderate response. Among the twelve hybrids H1 (L1 x T1), H2 (L1 x T2), H3 (L1 x T3), H5 (L2 x T1), H6 (L2 x T2) and H11 (L3 x T3) showed a high total response compared to the rest. Results from gca effects of parents indicated that L1 and T3 to be better combiner for reduced seed shattering indicating a scope for further utilization of these lines in plant breeding programmes for reduced shattering. When all the fourteen characters were considered, L2, T1, T2 and T3 recorded as better combiner. All the seven parents recorded to be moderate combiner for tillers per plant and flag leaf width. Scoring based on mean performance and combining ability effects for seed yield per plant revealed that, L2, L3 and T2 proved to be promising. T1, T2 and T3 proved to be promising parents for reduced seed shattering and T4 and Ll with a moderate response. When all the fourteen characters considered together L2, T1 and T2 were recorded as most promising parents.Specific combining ability studied among the cross combinations indicated that out of the twelve hybrids, H4, H5, H6 and H11 recorded high response and HI exhibited a moderate response for seed shattering. When the fourteen characters considered together, H3, H4, H5, H6, H8, H10 and H11 recorded to be better cross combination among the twelve characters. When mean performance and sea effect for all the fourteen characters for hybrids considered, the hybrids H1, H2, H3, H5, H6, and H11 reported high scores and H8 recorded moderate response. All the twelve hybrids recorded high significant heterobeltiosis for plant height, flag leaf width, panicles per plant, panicle length, test weight, kernel width, kernel length and shattering per cent. Based on the scoring for both mean performance and heterotic effect revealed that hybrids H5 recorded highest score followed by H3, H9, H11, and H1. Evaluation of hybrids based on mean performance, sea effects and heterosis revealed that hybrids H5, H6 and H3 recorded the first three positions among the twelve hybrids evaluated. Among this H5 and H6 have both the parents as better combiners. The remaining cross combination involving different combinations of parents viz., good x good, average x average, average x poor, poor x good, poor x average and poor x poor etc., can be used for transgressive breeding since there will be better recombinations in segregating generation.
Open Access
Management and utilization of water hyacinth (Eichhornia crassipes ( Mart.) Solms)
(Department of Agronomy College of Horticulture, Vellanikkara, 2018) Indulekha, V P; KAU; George Thomas, C
Water hyacinth is one of the most productive plants on earth, but it is also considered as the world’s worst aquatic weed. The phytoremediation capacity of water hyacinth and its management through ecofriendly means like silage making, composting, and mulching were studied at the College of Horticulture, Vellanikkara. The phytoextraction capacity of water hyacinth was evaluated through a purposive sampling by collecting plant and water samples from 20 sites in central Kerala. These samples were analysed for various nutrients including heavy metals. To study the association of plant nutrients with water nutrients, cross tabulation was done and dependence of plant nutrient factor on water nutrient was measured through Chi-square. The Chi-square statistic was significant for N, P, Mg, and Ni indicating that the level of nutrients could be brought to a minimum through water hyacinth. The accumulation of heavy metals in water hyacinth was in the order Fe> Al> Mn> Zn> Cr> Ni> Co> Hg> Pb> As. Among them, Pb content in plant samples was within the permissible limit, but contents of Fe, Cu, Cr, Zn and Ni were beyond the safe limits. The quality and palatability of silage prepared with fresh and wilted water hyacinth with or without rice straw or guinea grass and using molasses, cassava flour, or rice bran as additives was investigated. Considering the quality parameters such as pH, odour, and palatability, wilted water hyacinth with molasses (5%) or cassava flour (10%) and wilted water hyacinth with cassava flour (10%) and rice straw (10%) or guinea grass (10%) are the best options for utilizing water hyacinth as silage. The composting experiment consisted of four methods viz., Bangalore method, Indore method, phospho-composting, and vermicomposting. All the prepared composts had neutral to slightly alkaline pH. The lowest C: N ratio was recorded with vermicompost (11.58) followed by Bangalore compost (12.68). Nitrogen content at 3 months after composting (MAC) was higher in vermicompost and Bangalore compost. The highest N content at 6 MAC was observed in vermicompost (1.75%). Phosphorus content was higher in phospho-compost at 3MAC and 6 MAC. There was no significant difference in K content of different composts at 3 MAC. Calcium, Mg and S contents were high in vermicompost. Micronutrients such as Zn, Cu, Co, and Ni were higher with Bangalore composting. Heavy metals such as As, Cd, and Pb were not detected in any of the composts. None of the composts contained heavy metals beyond safe limits. A field experiment involving three mulch materials–jack tree leaves, green water hyacinth, and coconut leaves–were compared with no mulching in turmeric for two years. All the mulch materials including water hyacinth had positive effects on most morphological and physiological parameters of turmeric such as plant height, number of leaves, leaf area index, leaf area ratio, and dry matter production. In both years, rhizome yield was also higher in plots mulched with organic debris compared to non-mulch control. Nutrient uptake by the crop was also higher with mulching compared to non-mulched plots. All the mulch materials substantially affected weed density and weed dry weight and reduced turmeric-weed competition for different growth factors.
Open Access
Developing dwarf specific scar markers from WCT inbreds of coconut (Cocos nucifera L.)
(Department of Plant Biotechnology, Vellanikkara, 2018) Anto, Varghese; KAU; Sujatha, R
Coconut is an important subsistence and cash crop in the humid tropical regions of the world. The coconut palm is often called “the tree of life” because of its numerous uses as food, drink, fuel, building materials and so on. Coconut cultivars are mainly classified into two: tall and dwarf. West Coast Tall (WCT) is the most common and superior tall cultivar extensively cultivated all over the west coast region, especially in Kerala. One of the main methods of crop improvement in coconut is hybridization between tall and dwarf types. However the heterozygous nature of tall types is a hurdle in selection of mother palms and seedlings. Efforts to develop homozygous inbreds of WCT were started as early as 1924. Chethana (2016) studied the extent of inbreeding depression in second generation (S2) inbred palms and recorded morphological observations of one year old third generation (S3) inbred seedlings. Based on height, she classified the S3 seedlings into Low, Medium and High, before planting in the field. She also carried out the characterization of selected third generation (S3) inbreds using RAPD marker system along with tall (WCT) and dwarf palms (COD, CGD). The results revealed two dwarf specific RAPD bands in two of the S3 seedlings belonging to IAS3-1 and IBS3-1 family, when amplified with primers OPAU03 and OPAW15. However, as RAPD markers have low specificity and sometimes lack repeatability, converting them into Sequence Characterized Amplified Region (SCAR) markers is more advantageous. A tall specific SCAR marker was reported in coconut using primer OPA 09 (Rajesh et al., 2013). The present investigation was carried out in the departments of Plant Biotechnology, College of Agriculture, Padannakkad and College of Horticulture, Vellanikkara during the period 2016-2018 was undertaken with an objective of developing SCAR markers from dwarf specific RAPD marker for screening superior inbreds with dwarfing nature. DNA samples were extracted from total 54 genotypes, 22 seedlings belonging to the inbred families IAS3-1and IBS3-1, 10 seedlings from other three families viz, IIS3, IIIS3 and VS3, 14 dwarf seedlings (including COD, CGD and MYD) and 8 tall seedlings (WCT). These were subjected to RAPD analysis using the 3 reported primers viz, OPAU 03, OPAW 15 and OPA 09. Though OPAU03 showed polymorphism between tall and dwarfs, the bands lacked repeatability and hence this was not included in further analysis. OPA 09, which was reported to produce a tall specific band (Rajesh et al., 2013), confirmed the result in the present study also. Primer OPAW15 was successful in amplifying a polymorphic band of size around 320 base pair specifically in dwarf seedlings and it was not present in the tall cultivar (WCT). The polymorphic dwarf specific band produced by primer OPAW 15 was eluted and cloned in pTZ57R/T vector and transformed into E. coli DH5 alpha cells. Cloned cells were subjected to blue white screening and transformed ones were selected, the plasmid was isolated and sequenced. The sequence after vector screening was subjected to homology search using BLASTn. The DNA sequence of polymorphic band showed similarity with chromosome 2 of Solanum lycopersicum. Based on the sequence, one pair of SCAR primer was designed and tested for dwarf specific band. Dwarf specific amplicon was found in all the dwarfs but absent in the tall WCT seedlings. Hence, this was used to screen the S3 inbred seedlings which were classified as Low, Medium, and High based on their height at the time of planting, to confirm the effectiveness of this classification based on morphology. The result showed that the dwarf specific marker is present in S3 inbreds belonging to Low and Medium types but absent in all those seedlings classified as ‘High’ based on height. This shows that the classification based on height in the one year old seedlings is effective to some extent. However, some of the seedlings in ‘Low’ and ‘Medium’ category lack the marker, which indicate that a classification based on morphological and molecular marker is more effective than classification based on morphology alone. The dwarf specific SCAR marker developed in the present study after validation using other tall and dwarf cultivars, along with the earlier reported tall specific SCAR marker can be successfully employed in breeding experiments for marker assisted selection. The SCAR markers which distinguish tall and dwarf coconut cultivars can be used in screening seedlings at an early stage which would be of immense importance to nurseries and growers while establishing coconut plantations.
Open Access
Phosphorous and boron interactions in black cotton soils of kerala with respect to groundnut (Arachis Hypogaea L.)
(Soil science and agricultural chemistry, Vellanikkara, 2018) Shaniba, M; KAU; Beena, V
Balanced supply of nutrients is one of the most important factors determining crop yield. Sometimes the applied nutrients may not be available for plant use, as their availability depends on interaction between nutrients. When the supply of one nutrient element affects the absorption and utilization of other nutrient element, the elements are said to be in interaction and interactions may be negative or positive. In Kerala, black cotton soils are seen in Chittur taluk of Palakkad district occupying an area of approximately 2000 ha. These soils are sandy clay loam, dark, calcareous, neutral to alkaline (pH 7.0 to 8.5), high in clay content and CEC. These soils are sufficient in all nutrients except phosphorus (P) and boron (B). Finding the interaction between Band P in black soils will help to understand the factors determining the availability of these nutrients to crops. The present study was carried out in College of Horticulture, Vellanikkara during 2016-18. The objectives of the study were to find out the interactions of boron and phosphorus in black cotton soils of Palakkad and to assess the treatment level of boron (B) and phosphorus (P) for maximizing the yield. The study consisted of a field experiment with groundnut variety, K-6 in black cotton soils of Chittur, Palakkad followed by analysis of soil, plant and pod samples taken from the experimental field. Soil samples were collected from different locations of Chittur and analyzed for available P and B. Field experiment was carried out where deficiency of both P and B was noticed. Experiment was laid out in factorial RBD with 17 treatments and 4 replications. Treatment combinations were made with four levels of P and four levels of B with soil test based recommendations as control. N and K levels are kept same (based on POP recommendations of KAU) for all treatments except for the first treatment where soil test based recommendations was given. P0 - 0 kg ha-1, P1 - 60 kg ha-1, P2 -75 kg ha-1 and P3 -90 kg ha-1 were the four levels of P and B0 - 0 kg ha-1, B1 - 5 kg ha-1, B2 - 10 kg ha-1 and B3- 15 kg ha-1 were the four levels of borax. super phosphate (SSP) was used as source of P and borax was used as source of B. Physical characteristics of soil viz., texture and bulk density were analyzed before experiment and chemical characteristics viz., pH, EC, organic carbon, N, P, K, Ca, Mg, S, Fe, Mn, Zn, Cu and B were analyzed before and after the experiment. parameters like plant height and number of leaves per plant were recorded at flowering, pegging, pod setting and harvest stages and yield parameters like number of pods per plant and yield were recorded at harvest stage. Plant nutrient content was analyzed and uptake was computed at different stages viz., flowering, pegging, pod setting and harvest stages whereas pod nutrient content and uptake was computed only at harvest stage. Soil nutrient status, plant nutrient content and uptake of nutrients were affected by main effect and interaction effect of P and B. Application of P at 90 kg ha-1 and B at 0 kg ha-1 resulted in highest plant height and number of leaves per plant. Application of P at 90 kg ha-1 and B at 5 kg ha-1 resulted in highest number of pods per plant and yield. Application of P at 90 kg ha-1 and B 0 kg ha-1 resulted in highest protein content in groundnut. Application of increased dose of P reduced availability of B due to anionic competition. Application of P reduced the availability of Fe, Mn and Zn in soil due to the formation of insoluble compounds like Fe-P, Mn-P and Zn-P. Application of P enhanced the availability of N. K content in soil was reduced with increased dose of P application. Ca and S were increased due to its supply through fertilizer in soil. Plant nutrient content showed a decreasing trend from flowering to harvest stage. Application of P enhanced plant and pod P content and application of B reduced plant and pod P content. Content of N, P, K, Ca and S was increased with increased levels of P and content of Fe, Mn, Zn and B was reduced with increased dose of P. Content of N, P, S, Zn and B were higher in pod than plant. Uptake of nutrient followed an increasing trend from flowering to harvest due to increased dry matter production. The uptake of N, P, S, Zn and B by pod was higher compared to plant uptake.
Open Access
Economics of dairying in Thrissur district
(Department of Rural Banking & Finance Managemnet , College of Cooperation, Banking & Management, Vellanikkara, 2017) Greeni T, Thankachan; KAU; Molly, Joseph
Open Access
Plant growth-promotion and root knot nematode management in tomato by Piriformospora indica and rhizobacteria
(College of Agriculture, Vellayani, 2016) Shilpa, Varkey; KAU; Anith, K N
The study entitled “Plant growth-promotion and root knot nematode management in tomato by Piriformospora indica and rhizobacteria” was conducted at the Department of Agricultural Microbiology College of Agriculture,Vellayani during the period 2014-2016 with the objective to assess the potential of the root endophytic fungus Piriformosporaindicaand plant growth-promoting rhizobacteria in improving plant growth and suppressing root knot nematode infestation in tomato. The experiment was conducted as in vitro and in vivo studies involving interaction assay between the biological agents and the nematode pest, andin vivo pot culture studies. Egg hatching and J2 mortality asinfluenced by treatment withrhizobacteriaand their cellfree extracts (CFE) were analyzed.Cell free extracts of rhizobacteria significantly reduced egg hatching and increased the mortality ofMeloidogyne incognitajuveniles. After 72 hours, the minimum egg hatching was with CFE of Pseudomonas fluorescensAMB8 (22.33 %) followed by B. amyloliquefaciens (22.66 %) and the maximum was with B. subtilis(27%).Juvenile mortality was highly influenced by the cell free extracts of all the isolates. Higher rate of mortality was observed with undiluted CFE than the diluted ones. Mortality percentage ranged from 68.21% to 99.71% with highest accounted for CFE of B. amyloliquefaciens. Treatment with undiluted CFE of P. indicaresulted in mortality of the J2 by 98% and egg hatching was reduced to 23.33%. Allthe rhizobacterial strains(1x107bacterial cell/ml)negatively influenced the egg hatching(from 30 to 50%) as compared to the control(99 % hatching). Upon 72 hours of incubation, there was only 30 % egg hatching in the case of egg masses treated with Pseudomonas fluorescensAMB8 and in the case of Bacillus amyloliquefaciensit was 30.66 per cent. However, reducing the cell concentration in the test suspension of all the rhizobacterial strains had positive effect on egg hatching. Treatments with cell suspension of all rhizobacterial strainsshowed significantly low mortality of J2 juveniles, with highest mortality forB. amyloliquefaciens (8.56 %) indicating less influence by the rhizobacteria as such. Piriformosporaindicashowed no egg parasitism.Compatibility between Piriformosporaindicaandrhizobacteriawas assessed by dual culture plate assayunder in vitrocondition and it was found that B. pumilus and Pseudomonas fluorescensAMB8 were compatible with the fungus though the test medium differed. The compatible bacteria as single inoculation and combination with P. indicawere used for in vivo analysis. Pot culture experiments using sterile planting medium with single inoculation of the selectedrhizobacteria, Piriformosporaindica, and theircombinationsin the presence or absence of nematode were carried out. All treatments with P. indicashowed root colonization by the fungus.In the presence of nematode, percentage root colonization was found to be increased and the highest was for combination of P. indica and P. fluorescens AMB8. Higher biometric characteristics were observed with nematode untreated plants for all parameters.In the nematode inoculated treatments, application of combination of P. indicaandP. fluorescensAMB8had positive effect on leaf number, fruit number, shoot weight and root weight when compared to the control.Treatment withP.indica resulted in formation of less galls/plant (33.30), egg mass/root system (3.41), eggs/egg mass (306.405), number of nematodes/g of root (54.415) and final nematode population/100cc soil (58) as compared to the control plants, where the values were 142.24, 24.91, 663.54, 220.57, 294.16 respectively. The study established the biocontrol potential of P.indicaagainst root knot nematode in tomato. Application of P. indica in the protray seedling production ensures better performance in terms of plant growth and suppression of root knot nematode infection in the main field.

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