Browsing by Author "Deepa S Nair"

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Chitosan mediated metabolite elicitation and growth responses in kasthuri turmeric(curcuma aromatica)
(Department of plantation crops and spices, college of agriculture, Vellayani, 2019) Nivya J Thengumpally; Deepa S Nair
Cryoconservation of koovalam (Aegle marmelos L.Corr.) by encapsulation-dehydration technique
(Department of Plant Biotechnology, College of Agriculture, Vellayani, 2018) Deepa, E; Deepa S Nair
The study entitled “Cryoconservation of Koovalam (Aegle marmelos L. Corr.) by encapsulation-dehydration technique,” was carried out in the Department of Plant Biotechnology, College of Agriculture, Vellayani during 2015-2017. The objectives of the present study were to standardize a cryopreservation protocol for Aegle marmelos using encapsulation and dehydration technique and to assess the genetic fidelity of plantlets regenerated from encapsulated axillary buds after cryostorage, using molecular markers. Investigation was carried out in three phases viz., enhancement of multiplication rate, standardization of in vitro conservation using the encapsulation-dehydration technique and assessment of genetic fidelity of the regenerated plantlets using ISSR markers. Single node segments with axillary buds from in vitro maintained cultures were used as the explants in all the experiments. Among the twelve combinations of auxins and cytokinins were tried, MS (Murashige and Skoog, 1962) medium supplemented with BA 2 mg L-1 + IBA 0.5 mg L-1 was found to be the best treatment with respect to shoot multiplication (9.33 shoots per explant). The additives chitosan (CH), thidiazuron (TDZ) and adenine sulphate (AdS) at different concentrations were supplemented in two different media i.e. 1) hormone free MS medium and 2) MS + BA 2 mg L-1 + IBA 0.5 mg L-1 to study their effect on shoot proliferation. The best shoot proliferation response obtained for each additives were MS + BA 2 mg L-1 + IBA 0.5 mg L-1 + chitosan 10 mg L-1 (35.66 shoots per explant), MS + AdS 60mg L-1 (5.33 shoots per explant) and MS + BA 2 mg L-1 + IBA 0.5 mg L-1 + TDZ 0.02 mg L-1 (20.00 shoots per explant). Even though higher shoot proliferation was observed in CH and TDZ supplemented media, they exhibited morphological abnormalities. Normal shoots were obtained with AdS supplemented medium, but shoot proliferation was less compared to MS + BA 2 mg L-1 + IBA 0.5 mg L-1. Hence MS + BA 2 mg L-1 + IBA 0.5 mg L-1 was used as basal medium for cryopreservation studies. Encapsulation-dehydration technique of cryopreservation involved various steps like preconditioning, encapsulation, pre-culture, dehydration (desiccation), thawing and recovery. Nodal segments with single axillary buds were used as the explant. In preconditioning experiment, PC2 (sucrose 0.1M in semi solid MS for 7 days) was selected as the best preconditioning treatment, which produced maximum shoot proliferation (5.50 shoots per culture) when cultured on basal medium. Among different encapsulation treatments, maximum shoot proliferation of (6.66 shoots per culture) was obtained in the beads formed with sodium alginate 3.5 per cent in modified MS medium and calcium chloride 100 mM, when cultured on modified basal medium (½ MS + BA 2 mg L-1 + IBA 0.5 mg L-1). Pre-culture experiments were conducted using preconditioned and encapsulated explants. The pre-culture treatment selected was liquid MS medium supplemented with sucrose 0.5 M and DMSO 3 per cent for 3 days, which gave maximum shoot proliferation (3.66 shoots per explant) in modified basal medium. The preconditioned, encapsulated and pre-cultured beads were subjected to 0 to 7 h of desiccation under laminar airflow. The moisture content declined from 82 per cent to 12.60 percent on 7 h of desiccation. The desiccated beads were then cryopreserved in liquid nitrogen for 2h, followed by thawing for 30-60s at 40oC and inoculated on to recovery medium ½ MS + BA 2 mg L-1 + IBA 0.5 mg L-1. Survival (66.67 per cent) and regeneration (50 per cent) could be obtained only at 6h of desiccation when the moisture content was 19.50 per cent. The beads when stored in liquid nitrogen for different duration did not show any significant variation with respect to survival and regeneration. The genetic fidelity of plantlets regenerated from encapsulated axillary buds subjected to cryostorage were analysed using ISSR markers. Among the nine primers tried, four primers UBC 807 (AGAGAGAGAGAGAGAGT), UBC 840 (GAG AGA GAG AGA GAG AYT), UBC 847 (CACACACACACACACART) and UBC 826 (ACACACACACACACACC) that gave scorable (5-7) bands were selected for the study. The ISSR banding patterns of the cryoregenerated plantlets and control plants were identical, which indicated the genetic stability. This study was successful in developing a protocol for cryopreservation using encapsulation-dehydration technique in A. marmelos with 50 per cent regeneration efficiency.
Cryopreservation of chethikoduveli (Plumbago rosea L.) and assessment of genetic fidelity of regenerated plantlets using molecular markers
(Department of Plant Biotechnology, College of Agriculture, Vellayani, 2014) Anand Vishnu Prakash; Deepa S Nair
Cryopreservation of Koovalam (Aegle marmelos L.) using vitrification technique
(Plant Biotechnology , Cryopreservation , Koovalam , Aegle marmelos L, 2021-12-21) Parvathy, B.; Deepa S Nair
The research work entitled “Cryopreservation of Koovalam (Aegle marmelos L.) using vitrification technique” was conducted in the Department of Plant Biotechnology, College of Agriculture, Vellayani during the year 2020-2021. The objective of this study was to determine the effect of vitrification technique of cryopreservation on recovery and regeneration of A. marmelos plantlets and assessment of their genetic fidelity using molecular markers. In vitro cultures of A. marmelos were established via embryo culture and the nodal segments containing a single axillary bud were inoculated on MS medium supplemented with BA 2 mg L-1 and IBA 0.5 mg L-1 to enhance the release of axillary buds. The axillary buds obtained from these in vitro shoots were used as explant for the study. In vitro conservation of A. marmelos was attempted using the vitrification method of cryopreservation. Two vitrification techniques viz., simple vitrification and encapsulation-vitrification were tried. The main steps involved in vitrification protocol are preconditioning, encapsulation (in case of encapsulation vitrification), pre-culture, loading, vitrification, cryostorage, thawing, unloading and recovery. Nodal segments (ca. 5-8 mm) bearing single axillary buds were subjected to preconditioning in MS medium containing sucrose 0.1 M for 7 days. The preconditioned explants were encapsulated (in the case of encapsulation vitrification) using sodium alginate 3.5 % and CaCl2 100 mM. The preconditioned explants with and without encapsulation were subjected to pre-culturing in liquid MS medium containing DMSO 3 % and sucrose 0.5 M for 5 days at 4 ºC under dark conditions with medium change after every 24 h. The pre-treated explants were then transferred to a sterile cryovial containing autoclaved loading solution (liquid MS with glycerol 2 M and 0.4 M sucrose) and incubated aseptically for 20 min. Post incubation, the explants were treated with PVS2 or PVS3 solutions for different durations ranging from 0 to 210 min with 30 min interval. The vitrified explants were then plunged directly into liquid nitrogen and stored for 2 h. Following cryo-treatment, the explants were warmed in a water bath 68 maintained at 40 ºC for 2 min. The warmed explants were treated with unloading solution (liquid MS with sucrose 1.2 M) for 20 min and then, inoculated in regeneration medium (Half MS supplemented with BA 2 mg L-1 and IBA 0.5 mg L-1 ). Among the various treatments in both the techniques, non-encapsulated explants subjected to PVS2 treatment for 60 min alone survived. The survival and regeneration obtained were 65.57±1.57 % and 61.10±4.16 % respectively. The new bud initiation was observed in 28.33±1.02 days of inoculation in the regeneration medium. The cryo-recovered explants produced 2.09±0.44 shoots per explant, 1.72±0.10 nodes per shoot and 4.17±0.08 cm long shoots. Explants treated with PVS3 solution turned albino and did not show any signs of survival. The treatments in encapsulationvitrification techniques also did not show any sign of survival until eight weeks of inoculation in the recovery medium. Axillary buds obtained from single seeds, subjected to simple vitrification method of cryopreservation using PVS2 solution for 60 min were cryostored for 2 h, 1 day, 1 week, 2 weeks and 1 month in liquid nitrogen. No significant difference was observed in terms of survival per cent, regeneration per cent, days to bud initiation, shoots per explant, shoot length and nodes per shoot for various durations of cryostorage. The genetic stability of cryo-regenerated plants was determined using ISSR markers. Out of the eight primers screened, five primers viz., UBC-809 (AGAGAGAGAGAGAGAGG), UBC-819 (GTGTGTGTGTGTGTGTA), UBC-826 (ACACACACACACACACC), UBC-836 (AGAGAGAGAGAGAGAGYA) and UBC-840 (GAGAGAGAGAGAGAGAYT) gave clear distinct bands. The banding profile of control plants and cryo-regenerated plants were identical indicating that the regenerated plants were true to type. The simple vitrification technique standardised for the cryopreservation of A. marmelos using axillary bud as explant encompasses preconditioning in MS medium supplemented with sucrose 0.1 M for 7 days, pre-culture in liquid MS medium supplemented with DMSO 3 % and sucrose 0.5 M for 5 days, loading treatment (liquid 69 MS supplemented with glycerol 2 M and sucrose 0.4 M) for 20 min, vitrification with PVS2 solution for 60 min, cryostorage in liquid nitrogen, thawing at 40 o C for 2 min, unloading treatment (liquid MS supplemented with sucrose 1.2 M) for 20 min and inoculation in regeneration medium (Half MS supplemented with BA 2 mg L-1 and IBA 0.5 mg L-1 ). The standardised protocol resulted in 65.57 % survival and 61.10 % regeneration.
Effect of chitosan application on physiological, biochemical and molecular characteristics of Piper longum L.
(Department of Plant Biotechnology, College of Agriculture ,Vellayani, 2022-10-01) Abhijith K.; Deepa S Nair
The study on the "Effect of chitosan application on physiological, biochemical and molecular characteristics of Piper longum L." was carried out in the Department of Plant Biotechnology and Department of Plantation Crops and Spices, College of Agriculture, Vellayani, Thiruvananthapuram, Kerala during 2021-2022. The objective of the study was to investigate the physiological, biochemical and molecular responses of Piper longum to foliar application of chitosan (CHT). The plants raised from the rooted cuttings of long pepper variety, Viswam were exposed to foliar spray with varying concentrations of chitosan (1 g L-1, 2 g L-1, 3 g L-1, 4 g L-1) at 2, 4, and 6 months after planting (MAP). The control plants were devoid of chitosan application. The study was carried out in a completely randomized design (CRD) with four replications. The observations were taken on plant growth, physiological and biochemical parameters and molecular characteristics.
Establishment of in vitro regeneration systems from callus and protoplast in capsicum frutescens L.
(Department of Plant Biotechnology, College of Agriculture, Vellayani, 2018) Jancy J Sathyaraj; Deepa S Nair
The present study entitled “Establishment of in vitro regeneration systems from callus and protoplast in Capsicum frutescens L. was carried out in the Department of Plant Biotechnology, College of Agriculture, Vellayani during 2015-2017. The objective of the study was to establish callus culture from different explants in C. frutescens, to establish protocol for protoplast isolation from callus/leaf mesophyll and to culture protoplast. The study was carried out in two phases viz., establishment of callus culture and organogenesis; and standardization of protocol for protoplast culture. Callus was induced from leaves and internodal segments from in vitro raised seedlings. Among the 44 treatments in MS medium with different combinations of auxins (NAA, IAA, IBA, 2,4-D and picloram) and cytokinins (BA and Kn), 100 per cent callus induction was obtained in MS media supplemented with picloram 0.50, 1.00, 1.50 and 2.00 mg L-1 (C41, C42, C43, and C44), NAA 1.50 mg L-1, NAA 2.00 mg L-1(C3, C4) and BA 3.00 mg L-1 + NAA 1.00 mg L-1 (C29). Among the 78 treatments tried for organogenesis, calli obtained from C29 treatment showed organogenesis in MS + BA 3.00 mg L-1 + IBA 1.00 mg L-1 (R37) and (MS + BA 5.00 mg L-1 + IAA 2.00 mg L-1 (R61) in 41 and 90 days, respectively. The microshoots obtained recorded 83.33 per cent rooting in MS medium supplemented with IAA 1.50 mg L-1(Rt7) in 12.83 days. Leaves excised from in vitro seedlings, and calli produced in MS + BA 3.00 mg L-1 + NAA 1.00 mg L-1 (C29), were used as explants for protoplast isolation. Leaf bits incubated in cell protoplast washing (CPW) solution containing cellulase 2.00 per cent, macerozyme 0.50 per cent and mannitol 0.50 M (maintained at pH 5.8) for 6 h (DM28) in dark at 27oC, yielded (124 x 105) protoplast per g, with a viability of 95.16 per cent. The callus yielded maximum protoplast (36 x 105 protoplasts per g) in an enzyme combination of cellulase 2.00 per cent + macerozyme 0.50 per cent + mannitol 0.60 M (maintained at pH 5.8) after 4 h 91 (DM47) of incubation under same conditions. In protoplast purification, floatation medium with 21 per cent sucrose recorded maximum protoplast yield (30 x 105 protoplasts per g tissue and 10 x 105 protoplasts per g callus) and maximum viability (90.91 per cent and 100 per cent), from leaf derived and callus derived protoplast, respectively. The purified protoplasts with 10 x105 plating density initiated microcalli in liquid MS medium supplemented with mannitol 0.50 M, 2,4- D 0.50 mg L-1 and sucrose 30g L-1 (PCM5) in 45 days. Further development to visual colony formation of microcalli was obtained on addition of liquid MS medium supplemented with mannitol 0.40 M and sucrose 5g L-1, in 60 days from callus derived protoplast and in 70 days from leaf derived protoplast. In the study, maximum callusing response was obtained in MS medium with picloram 1.50 mg L-1. Organogenesis was obtained from the calli derived in MS medium with BA 3.00 mg L-1 and NAA 1.00 mg L-1. The shoot initiated from the calli in MS medium with BA 3.00 mg L-1 and IBA 1.00 mg L-1. The rooting of microshoots could be obtained in MS medium with IAA 1.50 mg L-1. In protoplast isolation, leaf gave higher protoplast yield and viability in CPW solution with cellulase 2.00 per cent, macerozyme 0.50 per cent and mannitol 0.50 M, incubated in dark for 6 h and callus, in CPW solution with cellulase 2.00 per cent, macerozyme 0.50 per cent and mannitol 0.60 M, incubated in dark for 4 h. The protoplasts purified in 21 per cent sucrose supplemented floatation medium and adjusted to a plating density of 10 x 105, initiated microcalli in liquid MS medium supplemented with mannitol 0.50 M, 2,4- D 0.50 mg L-1 and sucrose 30g L-1. The visual colony formation of microcalli was obtained on addition of liquid MS medium supplemented with mannitol 0.40 M and sucrose 5g L-1. In this study, a callus mediated in vitro regeneration system has been established in C. frutescens. A protocol has also been developed for protoplast isolation from leaf and calli, and its culture resulting in microcalli formation.
Evaluation of genetic stock of sanghupushpam (Clitoria ternatea L.) for yield, Alkaloid content and nitrogen fixing potential
(Department of Horticulture, College of Agriculture, Vellayani, 2000) Deepa S Nair; Reghunath, B R
The present study entitled “Evaluation of genetic stock of ‘Sanghupushpam’ (Clitoria ternatea L.) for yield, alkaloid content and nitrogen fixing potential” was carried out at the Department of Horticulture, College of Agriculture, Vellayani from June 1999 to January 2000. Seeds of twenty different accessions were collected from various locations from inside and outside the state. Thirteen accessions having high rate of seed germination were raised as intercrop in young coconut garden and maintained till seed maturation stage. The performance of the accessions in terms of growth, yield and physiological parameters were evaluated. Growth and yield parameters with respect to shoot, pod, root and root nodule characters were evaluated. Physiological parameters evaluated included leaf area index, leaf area duration, net assimilation rate, crop growth rate, relative growth rate, absolute growth rate and harvest index. Number of effective nodules was taken as an index for assessing nitrogen fixing potential of the plant. Leaf yield, shoot yield and root yield were significantly superior in the accession MP-90. MP-83 recorded significantly superior pod yield. The number of nodules was the highest in accessions MP-76 and MP-82. Crude alkaloid content was significantly superior in seeds of MP-74 and MP-76. Six accessions were selected based on yield , nodule characters and crude alkaloid content viz ., MP-90, MP-74, MP-83, MP-78, MP-76 and MP-82. Results of the present study indicated that Clitoria ternatea, is not a good proposition as an intercrop in young coconut garden. However, it may be worth studying the performance of the crop as a pure crop under open condition or as an intercrop in coconut gcirden with comparatively lesser shade (less than 50 per cent) than the situation of the present study.
Germination and plant growth responses in Ashwagandha (Withania Somnifera (L.) Dunal) and Kiriyathu (Andrographis paniculata (Burm.F.) Nees) to seed pretreatments
(Department of Plantation Crops and Spices, College of Agriculture, Vellayani, 2020) Namitha Nadesh; Deepa S Nair
Growth, yield and essential oil production responses to microbial elicitation in Ocimum basilicum L.
(Department of Plantation Crops and Spices, College of Agriculture, Vellayani, 2021) Rajeswari, E; Deepa S Nair
The seeds of O. basilicum used for the study were sourced from Anand Agricultural University, Gujarat. The study was carried out in two phases: Phase 1- Seed priming using fungal derivatives for enhanced germination. Phase 2- Evaluation of the effect of foliar application of fungal derivatives for growth, yield and essential oil production. In the first phase of study, the seeds were subjected to various priming treatments using fungal derivatives viz., Trichoderma viride cell wall extract (1 %) (TCWE), Trichoderma viride culture filtrate (1 %) (TCF), Piriformospora indica cell wall extract (1 %) (PCWE), Piriformospora indica culture filtrate (1 %) (PCF) and hydro priming, maintained upto 30 days after sowing. The seeds without any priming were taken as the absolute control. In the second phase of study, the 30 days old seedlings of O. basilicum were transplanted to grow bags. The foliar spray of corresponding fungal derivatives (cell wall extract and culture filtrate) at 1 % concentration were given to plants at fortnightly intervals from transplanting to 90 days after sowing. The treatment without any foliar application was taken as the absolute control. The seeds bioprimed with PCF @ 1 per cent recorded the highest germination per cent (96%), survival per cent (96%) and had taken minimum number of days (3 days) to initial sprouting. While TCF @ 1 per cent exhibited the highest germination index (34.50) and lowest mean germination time (6.29 days). With regard to seedling development, PCF @ 1 per cent recorded a significantly higher shoot length (21.50 cm), root length (19.50 cm), seedling length (41.00 cm) and seedling vigour index (39.37). The highest (1.07) allometric index was observed in the treatment PCWE @ 1 per cent. At 110 DAS, the plants subjected to foliar application with PCF @ 1 per cent exhibited higher plant height (80.20 cm), collar girth (6.03 cm), leaf area (4010.82 cm2 ), number of branches (28.00) and number of flowering shoots (104.00). The same treatment induced early flowering (55 days) in O. basilicum. The foliar spray treatment with PCF @ 1 per cent exhibited significantly higher total chlorophyll content (1.20 mg g-1 ) and polyphenol content (84.31 mg PE g-1 ) at 110 DAS. The plants subjected to foliar application with PCF @ 1 per cent recorded maximum leaf biomass (210.00 g and 19.04 g), stem biomass (135.33 g and 12.21 g), herbage yield (345.33 g and 31.25 g), root biomass (52.00 g and 4.63 g) and total plant biomass (397.33 g and 35.88 g) respectively, on both fresh weight and dry weight basis. The same treatment recorded the highest leaf biomass (125.33 g and 12.44 g), stem biomass (76.00 g and 7.31 g), and herbage yield (201.33 g and 19.75 g), on fresh weight and dry weight basis respectively, in the ratoon crop harvested 60 days after the first cut. PCF @ 1 per cent was also observed to give the highest essential oil content (2.11 per cent and 1.00 per cent) and oil yield (443.10 g and 19.04 g, respectively) in terms of both fresh and dry leaf weight. This is followed by PCWE @ 1 per cent and TCF @ 1 per cent in terms of oil content and yield. In the first phase of study, PCF @ 1 per cent gave better performance in terms of seed germination, seedling growth and seedling vigour index. The transplanted seedlings from the same treatment when subjected to foliar application with PCF @ 1 per cent at fortnightly intervals gave the highest plant growth, biochemical and yield parameters in the second phase of study. Hence, it can be inferred that biopriming followed by foliar application of the fungal derivative PCF @ 1 per cent would give superior performance in terms of plant growth, yield and essential oil production in O. basilicum.
Growth, yield and secondary metabolite production responses to microbial elicitation in Withania somnifera (L.) Dunal
(Department of Plantation Crops and Spices, College of Agriculture, Vellayani, 2021) Ragin Shaji; Deepa S Nair
The study entitled “Growth, yield and secondary metabolite production responses to microbial elicitation in Withania somnifera (L.) Dunal.” was conducted at the Department of Plantation Crops and Spices, College of Agriculture, Vellayani, Thiruvananthapuram during 2019-2021 with a view to evaluate the effect of bacterial inoculants on seed germination, seedling vigour, growth, yield and secondary metabolite production in W. somnifera. Seeds of W. somnifera were primed with B. amyloliquefaciens (Bam), B. pumilus (Bp) and B. velezensis (Bv) at 1x 108 cfu mL-1 individually and in combination for 24 h. Among these treatments, T7, the trio combination of Bam+Bp+Bv recorded the earliest germination (5.33 days) highest germination per cent (96.67), survival per cent (92.67) seedling vigour index (958.93), basal shoot girth (0.81 cm), number of leaves (6.07), leaf area (13.38 cm2 ), shoot length (5.77cm), root length (4.16 cm) and root volume (0.54 cm3 ). All the biopriming treatments with Bacillus spp. recorded superior germination and seedling parameters over the untreated control (T9) and hydropriming (T8). The seedlings from the first phase were subjected to root dip with the respective bacterial suspension for 30 min on transplanting. The morphological and yield determining parameters such as shoot length(78.99 cm), root length (21.27cm), number of branches (8.78), number of leaves (71.00), collar girth (3.91 cm), leaf area (5146.81 cm2 ) number of flowering branches (7.89), stem fresh weight (61 .85 g plant -1 ), stem dry weight(9.78 g plant -1 ), leaf fresh weight (45.89 g plant -1 ), leaf dry weight (5.07g plant - 1 ), root fresh weight (5.47g plant-1 ), root dry weight (1.44 g plant-1 ) 100 seed weight (0.26g ) root diameter (1.33cm), root volume (5.39 cm3 ) and harvest index (0.10) were observed to be significantly higher in T7, the trio combination of (Bam+ Bp+ Bv), which was observed to be on par with T5, dual combination of (Bam+ Bv). T5 was found to be superior in shoot fresh and dry weight, berry fresh and dry weight, number of berries and 133 seed yield per plant and total dry matter production (97.48, 17.51, 8.85 and 5.32 g plant-1 , 90.56, 7.35, 18.89 g plant-1 respectively, which was observed to be on par with T7. All the said parameters were significantly lower in untreated control. Seedlings treated with bacterial suspension of B. velezensis (Bv) recorded highest chlorophyll content in the leaves of W. somnifera at the time of harvest. The highest total alkaloid content in leaves (7.86 µg 100 mg-1 ) was recorded in dual combination of Bp+Bv which was on par with the other combinantions, Bam+Bv (T5) and Bam+Bp+Bv (T7). T5 recorded the highest protein and carbohydrate content (2.96 and 23.30 mg 100 mg-1 respectively) in the roots which was on par with T7. The withanolide content was superior (7.46 µg mg-1 ) in T7, Bam+Bp+Bv which was on par with T5, Bam+Bv and T6, Bp+Bv. The yield of biochemical parameters on per plant basis viz., total leaf alkaloids, total root withanolides were the highest (397.44 µg plant-1, and 10.77 mg plant-1 respectively) in trio combination of T7 which was on par with dual combination T5. The control treatment recorded significantly lower values in all the biochemical parameters observed. In the first phase of the study, the trio combination of Bam + Bp+ Bv (T7) gave the best performance in terms of seed germination, seedling growth and seedling vigor index, In the second phase, Bam + Bp+ Bv (T7) and Bam+ Bv (T5) gave superior performance, in terms of plant growth, yield and biochemical parameters.
In vitro conservation of chethikoduveli (Plumbago rosea L.) using encapsulation and vitrification techniques
(Department of Plant Biotechnology, College of Agriculture, Vellayani, 2017) Sowmya, A S; Deepa S Nair
Salicylic acid mediated metabolite elicitation and growth responses in long pepper (Piper longum L.)
(Department of plantation crops and spices, college of agriculture, Vellayani, 2019) Krishna Veni Harish; Deepa S Nair
Standardisation of nursery management practices in pachotti (Symplocos cochinchinensis (Lour.) S. Moore)
(Department of Plantation Crops and Spices, College of Agriculture, Vellayani, 2018) Ajil, M S; Deepa S Nair
The study entitled “Standardisation of nursery management practices in pachotti (Symplocos cochinchinennsis (Lour.) S. Moore)” was carried out in the Department of Plantation Crops and spices, College of Agriculture, Vellayani durng 2017-18. The objective of the study was to evaluate the propagation efficiency of different propagules viz., seeds, stem cuttings and root cuttings and to standardise the potting media for the nursery plants of pachotti. The propagules viz., seeds, stem cuttings and root cuttings for the study were sourced form Jawaharlal Nehru tropical Botanical Gardens and Research Institute, Palode, Thiruvananthapuram and from Wayanad district. The seeds were subjected to in vivo and in vitro germination studies. In in vivo study, among the pretreatments tried, viz., physical treatments, chemical priming and bio priming, only physical treatment of scarification (with sand paper) responded with a very low germination of 2 per cent. The germination commenced after two months of the treatment. Other in vivo pretreatments as well as in vitro treatments did not give any germination. In vegetative propagation, stem cuttings were exposed dto hormone/chemicals (auxins, phloroglucinol and salicylic acid (SA) pretreatments for two hours before planting. When pretreated with SA @ 10 and 20 mg L -1, at three months after planting, the hardwood cuttings responded with 30 pere cent survival, whith a shoot length of 2.99 mcm and 3.62cm, respectively. The semihardwood cuttings pretreated with SA@ 20 mg L-1 responded with 23.33 per cent survival with a higher shoot length of 3.72 cm. Both the hardwood and semi hardwood cuttings pretreated with SA 20 mgL-1 had on par values with respect to shoot length. Root cuttings were pretreated with different concentrations of various types of auxins. Root cuttings pretreated with IAA @ 250 mg L -1, after three months of planting responded with 33.33 per cent survival with a shoot length of 5.73 cm. Though root cuttings had slightly higher survival percent and shoot length, hardwood cuttings were selected for the valuation of potting media due to better availability and ease in procurement. The three month old hardwood cuttings pretreated with SA @ mgL-1 were then transplanted to ten different potting media comprising of two basal media viz., soil:coipith compost :cowdung (1:1:1) (B1) and soil : soirpith compost : vermicompost (1:1:1) (B2), and each in combination with biofertilisers @ 5g plant -1 viz., PGPR (Plant Growth Promotng Rhizobacteria) Mix I, Azospirillum, PSB (Phosphorus Solubilising Bacteria ) and AMF (Arbuscular Mycorrhizal Fungi). At fourth month after transplanting, B2 in combination with biofertilisers were found to be significantly superior to B2, B1 and B1 in combination with biofertilisers with respect to morphological parameters. B2 +PGPR Mix I recorded highest shoot length (11.50 cm) and number of leaves (10.50) which was on par with B2+Azospirillum, B2+PSB and B2+AMF; the highest number of branches (1.92) was observed in B2+ Azospiriillum which was on par with the treatments , B2+ PGPR Mix I, B2+PSB and B2+AMF. The fresh and dry weight of shoots were the highest (21.35 g and 4.78 g respectively) in B2 +PGPR Mix I which was on par with B2+ AMF. B2+ AMF recorded highest values (4.77 cm, 0.30 mm, 3.28 g and 0.0092 g, respectively) with respect to root growth parameters viz., root length, root girth , fresh and dry weight of roots. The physiological parameters, leaf area index (1.36) and leaf area duration (34.63 days) were the highest in B2+ PGPR Mix I which was on par with B2 in combination with other biofertilisers. The phytochemical analysis indicated that carbohydrate content (80.9 mg g-1) of plant tissue was the highest in B2+PGPR Mix 1, which was on par with B2+PSB, B2+Azospirrillum and B2+AMF. Chlorophyll content was found to the highest (1.20 mg g-1) in B2+ Azospirillum which was on par with B2+PGPR Mix I. The same treatment recorded the highest soluble protein content (20.31mg g-1) and it was on par with B2 in combination other biofertilisers. The nutrient analysis of plant tissue showed that nitrogen (2.22 percent ) and potassium (2.15 per cent ) content was significantly higher in B2+ Azospirillum. B2+PSB Recorded higher phosphorus content (0.26 per cent) among the treatments. The study indicated that nursery plants in the potting media B2 in combination with biofertilizers gave better performance with respect to morphological parmeters, physiological parameters, phytochemicals and plant nutrients. Among the various potting media tried, B2+AMF recorded significantly higher plant growth potential (0.522) followed by B2 + PGPR Mix I (0.428). In the study, hardwood cuttings were identified as the preferred planting material for the nursery establishment of pachotti. The cuttings could be treated with salicylic acid @ 20 mg L-1 for initial establishment of nursery plants. The preferred potting media for transplanting the established cuttings for raising the nursery plants of pachotti is Soil : Coirpith compost : Vermicompost (1:1:1) +AMF (5g/plant).
Utilization of pineapple (Ananas comosus(L) Merr.) biomass for biofuel production
(Department of Plant Biotechnology, College of Agriculture, Vellayani, 2014) Anoop, P; Deepa S Nair
A study on utilization of pineapple (Ananas comosus (L.) Merr.) biomass for biofuel production was conducted at College of Agriculture, Vellayani, Thiruvananthapuram during the period of 2013-14. Rising concern over depleting fossil fuel and greenhouse gas resulted in a high level of interest in nonconventional fuel originating from biorenewable sources including sugars, starches and lignocellulosic materials. Lignocellulosic materials constitute a substantial renewable substrate for bioethanol production that do not compete with food production and animal feed. Pineapple waste is a promising feed stock for alcohol production due to its abundance and ease of availability. Also it is a cheap substrate for biofuel production due to low lignin content and can undergo hydrolysis steps more easily. The feed stocks were prepared by drying and grinding of pineapple peel, pineapple fruit waste and pineapple plant residue separately. This is a method of physical pretreatment used for degradation of lignocelluloses and for reduction of cellulose crystallinity. The study on moisture content of the feedstocks using gravimetric method showed that pineapple plant residue has higher moisture content followed by pineapple fruit waste and pineapple peel waste. The estimation of sugar content of different feed stocks revealed that, pineapple fruit waste have highest values of glucose, fructose, xylose and sucrose compared to the other feed stocks and this higher levels of sugar content resulted in higher ethanol production during fermentation. Total dissolved solids was found to be maximum in pineapple fruit waste. Similarly total carbohydrate was recorded maximum in pineapple fruit waste followed by pineapple peel waste and lowest value was observed in pineapple plant residue. Estimation of cellulose, hemicelluloses and lignin content of the feed stocks revealed that pineapple plant residue have maximum cellulose content followed by pineapple fruit waste and pineapple peel waste. Whereas pineapple peel waste recorded maximum hemicellulose content. Lignin content was found maximum in pineapple fruit waste. To obtain a highly efficient conversion, pre treatment was performed for three feed stocks with acid and alkali which reduce the lignin content and make the sugar molecules accessible for fermentation. Acid and alkali pretreatment of the pineapple feed stocks resulted an increase in total reducing sugar and total non reducing sugar concentrations. The increase in sugar concentration in pretreated feedstocks is due to the hydrolysis of cellulose and hemicellulose in to sugars. The acid and alkali pretreatment decreased the lignin content, but a higher percentage removal of lignin was observed with alkaline pretreated pineapple feed stocks. The biochemical characterisation of the feed stocks revealed the sugar content and fermentation potential. To find out the effect of pretreatment fermentation was carried out in untreated and pretreated feed stocks with Saccharomyces cerevisiae and Zymomonas mobilis. Fermentation of untreated feedstocks gave higher alcohol percent than pre-treated feed stocks inspite of the fact that pretreatments resulted in an increase in total reducing and non reducing sugars and a decrease in the lignin content . This may be due to the production of various inhibitors or due to high salt formation during pH adjustments of the pretreated feedstocks. The results of percent conversion rate of reducing sugar to alcohol indicated that pineapple fruit waste have higher conversion rate than other feed stocks where as the percent conversion of non reducing sugar is found to be maximum with pineapple peel waste. pH of the fermenting medium also tend to become acidic. Characterisation of feedstocks and alcohol yield after fermentation showed that pineapple fruit waste is the most amenable feedstock for alcohol production than other two. The alcohol yield (8.34 per cent) obtained with untreated fruit waste using S.cerevisiae was found to be significantly higher than all other combinations tried. For the enhancement of fermentation and subsequent alcohol yield, cellulolytic microorganism was isolated from degraded pineapple waste. It was identified as Bacillus sp. by biochemical and molecular characterisation. Three modes of enhancement of fermentation were performed with pineapple fruit waste; Single batch bioconversion, simultaneous saccharification and fermentation (SSF) and separate hydrolysis and fermentation (SHF) using Saccharomyces cerevisiae and isolated native microorganism. Single batch bioconversion was found to be the best enhancement method yielding 11.09 per cent alcohol. The decreased level of ethanol in other enhancement methods may be due to the negative interaction of Bacillus sp. with Saccharomyces cerevisiae. The present study concluded that fruit waste is the best candidate for bioethanol production than other pineapple feed stocks tried. Single batch bioconversion using the cellulolytic organism, Bacillus sp. and fermenting organism, S. cerevisiae could bring about a substantial enhancement in alcohol yield.