Browsing by Author "Sulekha, G R"

Now showing 1 - 9 of 9

Improvement of in vitro somatic embryogenesis in cashew (Anacardium occidentale L.)
(Department of Horticulture, College of Agriculture, Vellayani, 1999) Rekha, S; Sulekha, G R
Studies were conducted for improving techniques for in vitro somatic embryogenesis in cashew during 1996-1999 in the Plant Tissue Culture Laboratory of the Department of Horticulture, College of Agriculture, Vellayani. Attempts were made to standardise the various stages of somatic embryogenesis, namely, induction, initiation, maturation and germination using nucellus and embryo mass as explants. Out of the two explants tried, nucellus responded better than embryo mass in initiating embryogenic callus/somatic embryoids. Induction of somatic embryogenesis from nucellus was found to occur at its maximum when cultured in darkness on MS basal medium having half strength major salts, supplemented with 2,4-D 1.0 mg/l, BA 1.0 mg/l, NAA 1.0 mg/l, sucrose 30.0 g/l, Activated charcoal 0.5 g/l and agar 6.0 g/l. The best treatment identified for the induction of embryogenic callus / somatic embryoids from embryo mass was MS basal medium supplemented with 2,4-D 4.0 mg/l, NAA 4.0 mg/l, kinetin 4.0 mg/l, adenine sulphate 40.0 mg/l, yeast extract 200.0 mg/l, PVP 250.0 mg/l, sucrose 30.0 g/l and agar 5.5 g/l, in dark culture condition at regulated temperature (26 ± 2°C). 2 Initiation of somatic embryoids from nucellus as well as embryo mass occurred at its best in darkness on MS basal medium supplemented with NAA 0.5 mg/l, kinetin 2.0 mg/l, adenine sulphate 40.0 mg/l, PVP 250.0 mg/l, yeast extract 200.0 mg/l, sucrose 30.0 g/l and agar 5.5 g/l. . Among the treatments tried for inducing proper maturation of the somatic embryoids, the maximum survival of embryoids was recorded on a combination of basal media with Bs major salts and MS minor salts supplemented with ABA 1.0 mg/l, coconut water 200.0 mlll, casein hydrolysate 100.0 mg/l, PVP 10.0 g/l, sucrose 40.'0 g/l and agar 5.0 g/l. Culture conditions did not influence the maturation process of the somatic embryoids. Maturation process was not found to be essential in inducing normal germination of the somatic embryoids. The cultures showed good response when subcultured from initiation media to germination media without a maturation phase. Germination of somatic embryoids occurred only in the presence of light, on a combination of basal media with Bs major salts and MS minor salts supplemented with BA 1.0 mg/l, PVP 10.0 g/l, coconut water 200.0 mlll, sodium chloride 0.1 per cent, cobalt chloride 10.0 g/l, sucrose 50.0 g/l and agar 6.0 g/l.
In vitro somatic embryogenesis in bael [Aegle marmelos (L.) Corr.]
(Department of Plantation Crops and Spices, College of Agriculture, Vellayani, 2003) Hima Sugathan; Sulekha, G R
Performance of spiny coriander (Eryngium foetidum L.)under different shade regimes
(Department Of Plantation Crops & Spices,College of Agriculture, Vellayani, 2008) Appukuttan, J; Sulekha, G R
The studies on the “Performance of spiny coriander (Eryngium foetidum L.) under different shade regimes” were carried out at the Department of Plantation Crops and Spices, College of Agriculture, Vellayani, during 2004-2006. The objectives were to evaluate the adaptability and performance of Eryngium foetidum L. under varying levels of shade and plant population densities and also to study the feasibility of cultivating Eryngium foetidum L. under the homestead conditions of Kerala. Its use, both as a flavouring agent and herbal medicine, and also as a home remedy for various ailments point towards its inclusion as an important item in Kerala homesteads. The performance of Eryngium foetidum was studied at three levels of shade (25, 50 and 75%) and four spacings (10cm  15cm, 15cm  15cm, 20cm  15cm and 30 cm  15 cm). High Density Poly Ethylene shade nets of appropriate mesh size were used for providing the required shade levels. Observations on growth parameters, physiological characters, growth analysis, yield characters, bio-chemical analysis, storage studies etc., were taken and the benefit: cost ratio was worked out. From the experiment, it was found that the crop performed best under 75 per cent shade level in most of the characters studied. Maximum yield (1411.04 g/plot of size 120  150 cm) was recorded under 75% shade level and also at a closer spacing of 10x 15cm (1131.41 g/plot). But the interaction effect of shade and population density on total herbage yield was not significant. On analysis, no measurable quantity of volatile oil could be estimated. The highest NVEE of 0.86 per cent was obtained from the plants grown under 75 per cent shade and a spacing of 30 × 15cm. From the storage studies it was concluded that under ambient temperature the leaves could be stored for a maximum of 5.2 days and 4.8 days when grown under 50 per cent and 75 per cent shade respectively, whereas under cold storage, the leaves from 75% shade could be stored for a maximum of 109.65 days without any deterioration. Maximum benefit: cost ratios of 1.28, 1.27 and 1.21 were obtained in the treatments 75% shade and 15cm × 15 cm spacing, 75% shade and 10cm  15 cm and 75% shade and 20cm  15 cm spacing, respectively. In general, as the intensity of shade increased, performance of the crop was better. Since the highest level of shade (75%) was found to be the best for the growth and yield of Eryngium foetidum, a higher level of shade, can be studied. Further studies on intercropping Eryngium foetidum under the existing homestead farming situations and other shaded situations like coconut, rubber, oil palm and other perennial tree crops are necessary. Popularization of the crop and development of appropriate marketing strategy are necessary for making the crop more remunerative.
Rooting of microshoots and ex vitro establishment of plantlets of bael (Aegle marmelos (L.) Corr.
(Department of Plantation Cropsand Spices, College of Agriculture, Vellayani, 2005) Surya D Aniyan; Sulekha, G R
Studies were conducted on “Rooting of microshoots and ex vitro establishment of plantlets of bael (Aegle marmelos (L.) Corr.)” for evolving techniques for in vitro rooting, ex vitro rooting and ex vitro establishment of plantlets of bael during 2003-2005 in the Department of Plantation Crops and Spices and Department of Plant Biotechnology, College of Agriculture, Vellayani, Thiruvananthapuram. The in vitro propagation techniques in bael have already been standardised. The microshoots 3.00 to 5.00 cm long with 3.00 to 4.00 leaves were taken from the cultures of previous study maintained in the Plant Biotechnology Laboratory, College of Agriculture, Vellayani, Thiruvananthapuram. The highest rooting of the microshoots (50.00 per cent) occurred in two treatments namely, MS basal medium supplemented with IBA 2.50 mg l-1, sucrose 30.00 g l-1 and agar 6.00 g l-1 and on the same basal medium supplemented with NAA 1.00 mg l-1, sucrose 30.00 g l-1 and agar 6.00 g l -1. The microshoots took the least number of days (8.00) for root initiation in full strength MS basal medium supplemented with IBA 0.50 mg l-1, sucrose 30.00 g l-1 and agar 6.00 g l-1. The highest number of roots (2.67) was obtained in full strength MS basal medium supplemented with IBA 2.50 mg l-1, sucrose 30.00 g l-1 and agar 6.00 g l-1. The best pre-treatment identified for ex vitro rooting was IBA 1000.00 mg l-1 for 20 s (quick dip) which gave the highest survival rate (50.00 per cent), number of roots (1.67) and length of roots (0.63 cm), compared with IBA 50.00 mg l-1 (slow dip). Different potting media like sand, soilrite, sand and soil (1:1), sand, soil and coirpith (1:1:1) and sand, soil and leafmould (1:1:1) were compared to study their effect on ex vitro establishment.. Sand was found to be the ideal potting media for ex vitro establishment. The highest survival rate (50.00 per cent), leaf number (4.67), plant height (3.67 cm), fresh weight (0.6501 g), dry weight (0.25 g), stomatal conductance (0.1165 cm S-1), leaf area index (0.1370) and crop growth rate (0.0291 mg cm-2 day-1) were obtained when planted out in sand than in other potting media. The effect of VAM (Glomus etunicatum and Glomus fasciculatum) in different potting media were also studied in the ex vitro establishment of plantlets. It was observed that mycorrhiza inoculated plants in a potting media of sand showed higher survival rate (66.67 per cent) than control (50.00 per cent). The highest values for number of leaves (6.00), plant height (4.30 cm), number of roots (2.33), fresh weight (0.6908 g), dry weight (0.2847 g), stomatal conductance (0.0383 cm S-1), leaf area index (0.1478) and crop growth rate (0.9921 mg cm-2 day-1) were obtained for the mycorrhiza treated plantlets in sand, compared to other mycorrhizal treated potting media. In the present investigation, protocols were evolved for the in vitro rooting of microshoots of bael (Aegle marmelos (L.) Corr.). But ex vitro rooting and ex vitro establishment gave only limited success. However, few plantlets could be acclimatized and were transferred to mud pots containing sand, soil and cowdung in the ratio 1:1:1 for observing further growth and establishment.
Standardisation of in vitro techniques for the rapid clonal propagation of bael (Aegle marmelos (L.) corr)
(Department of Plantation Crops and Spices, College of Agriculture, Vellayani, 2001) Hazeena, M S; Sulekha, G R
Standardisation of in vitro techniques for the rapid clonal propagation of mango (Mangifera indica L.)
(Department of Horticulture, College of Agriculture, Vellayani, 1996) Sulekha, G R; Rajmohan, K
Standardization of techniques for the in vitro propagation of mango (Mangifera indica L) varieties was attempted. The studies were carried out at the Plant Tissue Culture Laboratory, Department of Horticulture, College of Agriculture, Vellayani, during 1992-96. Attempts for the in vitro propagation via somatic embryogenesis, somatic organogenesis and enhanced release of auxillary buds were made. Six monoembryonic and six polyembryonic mango varieties were subjected to the initial response studies. Neelum (monoembryonic) and Vellari Manga (polyembryonic) varieties were selected for further detailed studies. Explants like nucellus, embryo mass, segments of leaf and inflorescence were used. The effects of culture medium (basal medium, major and minor nutrients, plant growth substances, casein hydrolysate, sucrose, glutamine, coconut water, activated charcoal, polyvinyl pyrrolidone, sodium butyrate, thidiazuron, polyethylene glycol, sodium chloride, silver nitrate, cobalt chloride and agar), culture conditions (light and temperature) and frequency of subculture on the various stages of somatic embryogenesis were studied. Among the various explants tried, somatic embryogenesis could be induced only from nucellus and embryo mass. In Neelum, somatic embryogenesis could be induced in 66.67 percent cultures of nucellus and 75.00 percent cultures of embryo mass. In vellari manga 83.33 percent cultures of nucellus and 66.67 percent cultures of embryo mass responded. Somatic embryogenesis from nucellus of Neelum could be best induced on half strength MS basal medium supplemented with GA3 5.0mg/l, 2,4-D 2.0mg/l, GA3 5.0mg/l, sucrose 60.0g/l, glutamine 400.0mg/l, coconut water 200.0ml/l, activated charcoal 2.5g/l and agar 5.0g/l. The ideal treatment for inducing somatic embryogenesis from nucellus of Vellari Manga was half strength MS basal medium supplemented with 2, 4-D 2.0 mg/l, GA3 5.0mg/l, sucrose 60.0g/l, glutamine 600.0 mg/l, coconut water 200.0ml/l, activated charcoal 2.5g/l and agar 6.0g/l. Subculturing in medium of the same composition at an interval of five days increased the percentage induction in Neelum (30.0 percent) and five to ten days in Vellari Manga (40.0 percent). The best treatment identified for the initiation of somatic embryoids from nucellus of Neelum was half strength MS basal medium supplemented with 2, 4-D 2.0mg/l, GA3 5.0mg/l, BA 1.0mg/l, sucrose 60.0g/l, glutamine 400.0mg/l, casein hydrolysate 500.0mg/l, coconut water 200.0ml/l, activated charcoal 2.5g/l and agar 5.0g/l. The ideal treatment for the initiation of somaticembryoids from nucellus of Vellari Manga was half strength MS basal medium supplemented with 2, 4-D 0.5mg/l, GA3 5.0mg/l, BA 1.0mg/l, sucrose 60.0g/l, glutamine 400.0 mg/l, case in hydrolysate 600.0 mg/l, coconut water 200.0ml/l, activated charcoal 2.5g/l and agar 5.5g/l. Subculturing at an interval of ten days in Neelum and five to ten days in Vellari Manga was beneficial for the initiation of somatic embryoids. The corresponding percentage of initiation of somatic embryoids was 66.67 in Neelum and 55.56 percent in Vellari Manga. A medium containing B5 major salts and MS minor salts supplemented with abscisic acid 5.0mg/l, sucrose 40.0g/l, casein hydrolysate 100.0mg/l, coconut water 200.0ml/l, polyvinyl pyrrolidone 10.0g/l and agar 4.5g/l was the best for supporting the maturation of the somatic embryoids of Neelum. The best medium for the maturation of the somatic embryoids of Vellari Manga contained B5 major salts, MS minor salts, abscisic acid 4.22mg/l, sucrose 40.0g/l, casein hydrolysate 100.0mg/l coconut water 200.0ml/l, polyvinyl pyrrolidone 10.0g/l and agar 5.0g/l. The size of embryoids was the highest (1.0-1.5cm long) when subcultured at an interval of ten days for Neelum and fifteen days (0.5-1.5cm long) for Vellari Manga. Incubating the cultures in darkness at 26 ± 20C favoured the induction, initiation and maturation of somatic embryoids of both the varieties. Near-normal germination of the somatic embryoids of Neelum was observed when cultured on a medium containing B5 major salts and MS minor salts, BA 0.1 mg/l, sucrose 40.0g/l, sodium chloride 0.5g/l, cobalt chloride 10.0 mg/l, polyvinyl pyrrolidone 10.0g/l and agar 5.5g/l. Near-normal germination of the somatic embryoids of Vellari Manga was observed on a medium containing B5 major salts and MS minor salts, BA 1.0 mg/l, sucrose 50.0g/l, sodium chloride 0.5g/l, cobalt chloride 10.0 mg/l, polyvinyl pyrrolidone 10.0g/l and agar 5.5g/l. A few germinated embryoids were planted out. However, they did not survive. Histological and morphological studies ascertained the status of the somatic embryoids formed. Scanning electron microscope studies depicted the morphological features of the developmental stages of the somatic embryoids. Attempts to standardize in vitro propagation via somatic organogenesis and enhanced release of auxiliary buds were not successful. However, de-diffrentiation could be induced from leaf segment explants of Neelum and Mulgoa.
Standardisation of organic manures and effect of microbial inoculants on growth, yield and quality of kasthuri turmeric (Curcuma aromatica Salisb.)
(Department of Plantation Crop and Spices, College of Agriculture, Vellayani, 2009) Nirmalatha, J D; Sulekha, G R
Standardization of techniques for better rooting and growth of orthotropic shoots in black pepper (Piper nigrum L.)
(Department of plantation crops and spices, College of Agriculture, Vellayani, 2014) Nimisha Mathews; Sulekha, G R
The present study on “Standardization of techniques for better rooting and growth of orthotropic shoots in black pepper (Piper nigrum L.)” was carried out at the Department of Plantation Crops and Spices, College of Agriculture, Vellayani during 2012- 2014. The objective of the study was to standardize techniques for profuse rooting and vigorous growth of orthotropic shoots of black pepper so as to produce quality planting material. The experiment was laid out in completely randomized design consisting of 10 treatments with 3 replications. All the treatments were tried using 2 node and 3 node semi hardwood cuttings of orthotropic shoots of black pepper. The treatments consisted of IBA (500 ppm and 1000 ppm), common sugar solution (1 per cent, 2 per cent and 3 per cent), AMF, Azospirillum 15 per cent and Psuedomonas 15 per cent. Solarized potting mixture enriched with Trichoderma was used for all the treatments including control and PGPR Mix -II was drenched uniformly in all treatments except absolute control. In the experiment with 2 node cuttings, T7 (Azospirillum 15 per cent) was found to be superior for most of the growth characters like minimum number of days for sprouting and number of days for 50 per cent sprouting . The same treatment recorded the highest value for height of sprouted cutting, length of leaf, breadth of leaf and leaf area. But the maximum values for number of leaves, petiole length, internodal length, root volume and number of roots was recorded in T2 (IBA 1000 ppm). In experiment with 3 node cuttings, T2 registered minimum number of days for sprouting, number of days for 50 per cent sprouting, highest values for height of sprouted cutting, number of leaves, petiole length, number of roots and root volume. The anatomical characters when studied, leaf cuticle thickness was highest in 2 node cuttings treated with T5 (common sugar solution 3 per cent) and in 3 node cuttings treated with T6 (AMF). The number of vascular bundles in leaf was found highest in T2 (IBA 1000 ppm) for both 2 node and 3 node cuttings. But the number of vascular bundles in root was highest in T1 (IBA 500 ppm), both in the case of 2 node and 3 node cuttings. For stomatal frequency, T7 showed maximum value in both the cases. The treatment T8 (Psuedomonas 15 per cent) recorded highest value for total dry matter production in both the experiments. The biological properties of potting mixture (after the experiment) showed that, AMF colonization and spore count was maximum in T6 for 2 node and 3 node cuttings .The observation on total actinomycetes load was highest in T7 in both the experiments. The treatment, T7 showed the highest percentage of success in the establishment of 2 node orthotropic cuttings which was on par with T1 and T2. With 3 node cuttings also T7 and T1 showed highest percentage success in the establishment of cuttings. From the results, it can be concluded that 2 or 3 node cuttings with Azospirillum 15 per cent or IBA 1000 ppm or IBA 500 ppm were found to be the best treatments for better rooting and growth of orthotropic shoots in black pepper (Piper nigrum L.) when planted in solarized potting mixture enriched with Trichoderma. However, 2 node cuttings are preferred because the availability of orthotropic shoots are scarce in black pepper.
Studies on the effect of plant population density and age at transplanting on the growth, frequency of harvest and total vegetative yield in amaranthus (Amaranthus gangetlcus Linn.)”
(Department of Horticulture, College of Agriculture, Vellayani, 1980) Sulekha, G R; Mohanakumaran, N
Investigations wore undertaken at the College of Agriculture, Vellayani to study the effect of plant population density sad age at transplanting on the growth, frequency of harvest and total vegetative yield in amaranthus. Bach of -the three groups of amaranth seedlings aged 15 days (A1,20 days (A2) end 25 days (A3) were transplanted, at three spacings namely 10 x 10 cm (S1). 15 x 10 cm (S2) end 20 x 10 cm (S3) In the population density trial low density plants (transplanted at 20 x 10 cm) exhibited overall better growth and quality characteristics. With regard to all the characters contributing to yield/harvest;, and total yield, except yield/unit area, the low density plants exhibited their clear superiority over the medium, density and high density plants.Increased number of harvests was also obtained when planted at wider spacing. However for obtaining higher yield/unit area, transplanting at 10 x 10 cm seemed to have advantage over the others. Such closely planted amaranthus came to flowering faster than the widely spaced ones. The investigation carried out with a view to understanding the effect of age at transplanting on the growth,c yield and quality in amaranth, revealed that the 25 day-old seedlings when transplanted gave better growth. With regard to the quality aspects also, the 25 day-old seedlings seemed to have a slight edge over the others. However these plants showed early initiation of flowering, thus limiting the number of possible harvests. Further,when yield and yield attributes were considered, the 15 end 20 day-old seedlings performed better. Considering all the aspects together, transplanting of 15 to 20 day-old seedlings can be recommended for obtaining higher weight of leaves/plant, higher weight of stem/plant, better leaf/stem ratio, higher yield/plant, higher yield/m end more number of harvests.