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Open Access
Evaluation of f 1 hybrids resistant to bacterial wilt and inheritance of resistance in brinjal (lolanum melongena L.)
(Department of Olericulture, College of Horticulture, Vellanikkara, 1991) Geetha, Varghese; Abdul, Vahab M.
The present studies "Evaluation of F hybrids resistant to bacterial wilt and inheritance of resistance in brinjal ( Solanum melongena L . ) were conducted during February 1990 to July 1991in the vegetable research plots of Kerala Agricultural University,Vellanikkara. Evaluation of F hybrids over 4 environments revealed that all the 3 hybr ids were superior to their parents for yield during all the four seasons. It also indicated significant role of genotype x environment interaction in the yielding abi l ity of the hybrids. Considering wilt resistance the hybrids were not superior to their parents. Varietal difference was observed for plant height, fruits/plant, fruit weight, fruiting period and productive flowers. Estimation of heterosis of three F^s over their parents revealed significant heterosis for plant height, days to flower, days to first fruitset, days to harvest, primary branches/plant, total fruits/plant, total yield/plant, average fruit weight and fruiting period. All the three hybr ids viz. Surya x Pant Rituraj, SM 6-6 x SM 132, SM 6-2 x Pusa Purple Cluster were stable. Study on the nature of inheritance showed that resistance to bacterial wilt is inherited in a recessive and monogenic manner.
Open Access
Effect of time of planting and growth regulators on flowering and vase life of Gerbera jamesonii
(Department of Pomology and floriculture and Landscaping, College of Horticulture,Vellanikara, 1993) Suma, P; KAU; Lila Mathew, K
Studies were carried out in the Department of pomology and Floriculture, College of Horticulture, Vellanikkara, Thrissur, during 1991 – 93 to examine the effect of time of planting and growth regulators on flowering and vase life of gerbera. Four varieties, namely , Eoliet, Presley, Pritty and Sunbird and five treatments, viz., GA 50 ppm, GA 100 ppm, CCC 500 ppm, CCC 750 ppm and control, were tried. Varieties were found to have significant influence on both vegetative as well as the floral characters whereas the treatments did not have any significant effect on vegetative characters of the Gerbera cultivars in general, when evaluated in the first season. In the second season both varietal and treatment effects were not consistent. Variety Presley was found to be early flowering while Eoliet was late flowering. GA 50 ppm and GA 100 ppm hastened flowering whereas CCC 500 ppm and CCC 750 ppm delayed it. In general the longevity of flowers was maximum in varieties Eoliet and Sunbird. Variety Presley had the least longevity. Among the treatments, CCC 750 ppm and GA 50 ppm increased the longevity of flowers in field. Maximum number of blooms was produce by Presley and the minimum by Eoliet. In general GA 100 ppm and CCC 750 ppm increased the number of blooms. In general CCC 750 ppm, GA 50 ppm and GA 100 ppm had a significant positive influence on flower diameter. In general variety sunbird had the maximum stalk length and diameter, while Pritty produced the shorest stalks. CCC 500 ppm and CCC 750 ppm had the best effect on stalk length. Vase life was found to be significantly increased by GA 100 ppm and CCC 750 ppm treatments given to the plants. Five per cent sucrose + 20 ppm AgNO3 significantly increased the longevity of flowers in vase. Planting in June was found to be better than October planting with respect to vegetative as well as floral characters, especially for number of flowers and flower diameter. Among the varieties, with respect to growth and number of flowers, Presley was found to be superior. In the correlation studies flower number was found to have positive and highly significant correlation with plant height and leaf area whereas flower diameter had significant negative correlation with leaf area and stalk length. Petiole length, stalk diameter and leaf number had positive correlation with this character. Vase life had significantly positive correlation with fresh weight of flowers.
Open Access
Induction of Genetic Variability in Musa Sp. Var. Nendran By in Uitro Methods
(Department of pomology and floriculture, College of horticulture,Vellanikkara, 1993) Mini Balachandran; P.K.Valsalakumari
Investigations were carried out at the Department of Pomology and Floriculture and Plant Tissue Culture Laboratory of the All India Co-ordinated Floriculture Improvement Project, College of Horticulture, Vellanikkara, Thrissur, during 1991-93 on the induction of variability in the banana variety Nendran (Musa AAB ‘Nendran’) by in vitro methods. Explants utilized for the study were shoot tip and eye bud for direct organogenesis through enhanced release of axillary buds and shoot tip, flower base, inflorescence axis, embryonic leaves and scalp for somatic organogenesis/embryogenesis. For culture establishment, axillary shoot initiation and in vitro rooting, different growth regulators, like NAA, 2, 4-D and 2, 4, 5-T (auxins) and BA and kinetin (cytokinins) were made use of. The plantlets produced in vitro were subjected to hardening treatments to ensure a better establishment of planted out plants and their growth parameters were studied. For shoot tip and eye bud explants, a combination of treatments involving, an initial dipping of explants in emisan (0.1 per cent) for 30 minutes followed by dipping in norfloxacin (0.1 per cent) for 30 minutes followed by dipping in norfloxacin (0.1 per cent) for 30 minutes and finally rinsing the explants in mercuric chloride (0.1 per cent) for 20 minutes was found to be best, but for flower base and inflorescence axis explants, emisan (0.1 per cent) treatment for 20 minutes and for embryonic leaves, dipping in alcohol for one second were in the best. Better and speedier establishment and growth of shoot tip and eye bud explants were observed on MS (semi-solid) medium containing NAA 2 ppm + BA 5 ppm. Addition of activated charcoal (500 mg per litre) to the medium, reduced media and explant discolouration due to polyphenol oxidation. When the performance of the shoot tip and eye bud explants was compared, eye bud explants took more time for culture establishment and growth. In shoot tip culture, on an average, each explant released 8.66 axillary shoots in the treatment involving MSb*+ NAA 2 ppm + BA 10 ppm. In the case eye bud, on an average, each explant released five axillary shoots. Continuous sub culturing was carried out at two week interval to assess the variation induced to cultured plants due to repeated subculturing. It was found that, the number of shoots produced per culture was not constant in all the subcultures. Still, the axillary shoots produced per explant per culture vessel increased at the mean rate of 5.90. BA alone at higher concentration (10 ppm) resulted in colloid (globular semi-hard, light green callus like structure) formation and subsequent regeneration. MSb*: MS medium containing half concentration of inorganic salts and full concentration of organic growth factors. For in vitro rooting, MSb medium containing NAA 10 ppm and AC 0.05 per cent was found to be effective for early root initiation and the maximum number of roots per shoot was produced at the treatment involving MSa* +NAA 5 PPM+ AC 0.05 per cent. Of the various explants, viz., shoot tip, inflorescence axis, flower base, embryonic leaves and scalp(in vitro) tried for initiating collus scalp and embryonic leaves recorded maximum response. Among the media tried for callus initiation, MSb media at liquid consistency was found to be more effective. Maximum callus index (266) was recorded for the treatment combination involving 2, 4-D 7 ppm and BA I ppm. For callus differentiation the treatments involving 2, 4-D and BA, BA alone and basal MS media resulted in rhizogenesis, and treatments involving 2, 4-D alone produced embryoid like structures from scalp callus. No shoot organogenesis was observed. Also treatments were conducted with changed levels of nitrate source in the media, but they did not give any favourable results. Embryoid like bipolar structures were recovered from scalp callus when they were transferred to media devoid of growth regulators. To study the variation, if any, induced due to derail subculturing, the shoots obtained from each subculture cycle (through enhanced release of axillary buds) were isolated and their MSa* : MS medium containing full concentration of inorganic salts and organic growth factors identify maintained. The shoots thus separated were rooted and planted out after subjecting them to a process of hardening. Somatic chromosome counts were made at the root tips of plantlets from 10 subcultures to confirm the ploidy. All the plants were triploids (2n = 33). The plantlets from different subcultures were planted out in sand, which was found to be the best medium. Observations made on growth parameters, at fifteen days interval, revealed that the plants from subcultures differed significantly with respect to the rate of growth in height and leaf area.
Open Access
Refinement of in vitro propagation technique in pineapple var. mauritius and mass multiplication of elite clones
(Department of pomology and floriculture, College of horticulture,Vellanikkara, 1996) Jo Jose C; Radha T
The studies on refinement of in vitro propagation technique in pineapple var. Mauritius and mass multiplication of elite clones were conducted at Kerala Horticulture Development Programme, Kerala Agricultural University, Vellanikkara during 1993 – ’95. Based on the survey conducted at the major pineapple growing areas, namely, Vazhakulam – Muvattupuzha regions of Ernakulam district, five elite clones of Mauritius variety with higher yield and other desirable fruit characters were selected propagules from the selected clones were planted at Vellanikkara for taking explants for their mass multiplication through refined in vitro propagation techniques. For shoot tip explants, treatment with emisan 0.1 per cent for 35 minutes followed with mercuric chloride 0.1 per cent for 10 minutes and for lateral bud explants treatment with emisan 0.1 per cent for 10 minutes followed by 0.1 per cent mercuric chloride for three minutes was found to be the ideal surface sterilization treatment. Culture establishment and growth initiation of shoot tip explants from different sources (suckers, crowns and slips) and lateral bud explants were better in MS medium supplemented with BAP 3 and 4 mg 1-1. Explants from shoot tips were found to be better than those from lateral buds for achieving faster culture establishment and growth initiation. Enhanced release of axillary buds was the maximum in Ms medium containing BAP 4.0 mg 1-1. Among the different subculture stages, multiple axillary bud production was higher in second suculture stage. Addition of casein hydrolysate 100.0 mg 1-1 in to the medium with BAP 4.0 mg 1-1 favoured the production of axillary buds. Adventitious bud initiation from sucker shoot tips was fastest in MS medium supplemented with BAP 5.0 mg 1-1 + NAA 1.0 or 0.5 mg 1-1. For adventitious bud production from lateral buds, treatment with BAP 7.5 mg 1-1 + NAA 1.0 mg 1-1 was the best. Proliferation rate of adventitious buds was maximum in MS medium supplemented with BAP 4.0 mg 1-1 + NAA 0.5 or 1.0 mg 1-1. Rate of multiplication of adventitious buds was higher in liquid medium under shake culture condition, than in solid medium. Faster shoot regeneration and increased vigour of the shoots were resulted in growth regulator free MS medium. However, highest number of shoots were produced in MS medium supplemented with BAP 1.0 mg 1-1. Liquid medium under shake culture condition was found superior of solid media with respect to initiation of shoots and mean number of shoots, however, the latter resulted in longer shoots. In vitro rooting was fastest in MS medium, without any growth regulator, which produced longer and normal roots with secondaries and root hairs. Though addition of NAA (3 mg 1-1) resulted in increased number of roots, they were very short and hair like. Stationary liquid medium was found superior to solid
Open Access
Response of Gladiolus to Rapid Cloning Through in Vitro Techniques
(Department of pomology and floriculture, College of horticulture,Vellanikkara, 1995) Sakkeer Hussain, C T; KAU; Geetha, C K
Investigations were carried out to study the response of gladiolus to rapid cloning through in vitro techniques at the Department of Pomology and Floriculture and Plant Tissue Culture Laboratory of All India Co-ordinated Floriculture Improvement Project, College of Horticulture, Vellanikkara, during 1992-94. The main objective was to identify the most suitable explant and media combination for in vitro cloning. The explants used were corm axillary buds, cormel tips, inflorescence nodal segments (for enhanced release of axillary buds), inflorescence internodal segments, flower buds, flower bud bracts, root segments (for somatic organogenesis) and leaf segments (for somatic embryogenesis). The best season for the collection of corm axillary buds and cormel tips was from September to May. Surface sterilization of the explants could be effectively done with 0.1 or o.2 per cent mercuric chloride and the duration of treatment varied from I to25 minutes. Culture establishment of the corm axillary bud, cormel tip explants were better in MS medium supplemented with BAP ranging from 1.0 mg 1 -1 to 4.0 mg 1-1. The concentration of BAP required varied according to the stage of development of corms and cormels. Higher levels of BAP was ideal during early stages of development of corm and cormels. Of the different media (White’s, SH and MS) tried, MS medium was found to be the best culture establishment (Stage 1) when supplemented with 3.0 mg 1-1 BAP. Elongated shoots of Stage I were subjected to shoot proliferation (Stage 2). Multiple axillary bud production was very high when the MS medium was supplemented with BAP 1.0 mg 1-1 and NAA 0.5 mg 1-1 or BAP 2.0 mg 1-1 and NAA 0.5 mg 1-1. Callus production from the base of the elongated shoots were observed when the concentration of NAA increased in the medium. Of the different cytokinins (BAP, kinetin and 2ip) tried, BAP was found to be the best in Stage 2. Frequent subculturing onto the MS medium containing BAP 2.0 mg 1-1 and NAA 0.5 mg 1-1 increased the production of multiple axillary buds. These when transferred to the MS medium devoid of growth regulators resulted in elongation of shoots. The elongated shoots produced maximum number of roots in the MS medium containing 1.0 mg 1-1 IBA under the exclusion of light. However, early rooting was obtained in MS liquid medium devoid of growth regulators. Plantlet survival was maximum when treated with 0.2 per cent Bavistin immediately after removing from the culture vessels, followed by treatment with 0.2 per cent mancozeb and norfloxacin at the time of transplanting and post planting treatment with 1/10 MS solution and drenching with triadimefon 20.0 mg 1-1 at three days interval inside improvised mist chamber. Direct organogenesis could be obtained from immature inflorescence segments in modified MS medium supplemented with 15.0 mg 1-1 NAA and 3.0 mg 1-1 BAP. Among the various explants tried for callus mediated organogenesis, callus index was the maximum (400) when immature inflorescence segments were inoculated to the modified MS medium supplemented with NAA 15.0 mg 1-1 in 16 h photoperiod and also in the medium supplemented with 15.0 mg 1-1 NAA + 2.0 mg 1-1 BAP and kept under exclusion of light. The callus derived from inflorescence segments differentiated into shoots in the MS medium supplemented with 3.0 mg 1-1 BAP and also in the medium supplemented with 1.0 mg 1-1 BAP and 0.5 mg 1-1 NAA. Callus also could be obtained from flower buds and flower bud bracts. The callus derived from the corm axillary buds and cormel tip explants in Stage 2, differentiated in the basal MS medium devoid of growth regulators or supplemented with 20.0 ml 1-1 coconut water and also in the medium with 0.5 mg 1-1 BAP. The root segments (both in vitro and in vivo) produced callus in MS medium supplemented with 1.0 mg 1-1 NAA and the differentiation was obtained in the medium containing 3.0 mg 1-1 BAP an 1.0mg 1-1 NAA. Leaf segments failed to develop callus. However, the explants collected from the leaf covering the inflorescence boot leaf) when cultured in modified MS medium supplemented with 15.0 mg 1-1 NAA and 1.0 mg 1-1 BAP and incubated under darkness for three months developed somatic embryos. In vitro corm production was noticed in the cultures, if planting out was delayed. Earliest and large sized corm induction was made possible in elongated shoots of gladiolus from Stage 2 in Ms medium containing 5.0 per cent sucrose, 0.5 mg 1-1 NAA and 5.0 mg 1-1 triadimefon kept under etiolated condition. The size of the in vitro produced corms enlarged from 0.2 cm to 2.3 cm in the MS liquid medium containing 5.0 per cent sucrose and 3.0 mg 1-1 triadimefon.
Open Access
Vegetative, Floral and fruit characters in mangosteen (Garcinia mangostana L.)
(Department of Pomology and Floriculture, College of Horticulture, Vellanikkara, 1996) Ajay Alex; KAU; Sarah, T George
The present investigations on the growth habit, phases of growth, flowering and floral biology, fruit development, seed viability and storage life of mangosteen were carried out in the Department of Pomology and Floriculture, College of Horticulture, during the period 1994-96. The studies indicated that shoot growth in mangosteen coincided with the main flushing season from June to August and with a second one from January to February. Maximum shoot growth was observed during July. The growth of the tree was slow, with an extension growth of 6.91 cm in an year. The tree had a monopodial orthotropic trunk meristem which showed continuous growth. Laterals exhibited plagiotropy, sympodial growth and sylleptic branching habit. Leaf arrangement was spiral in the seedling stage but distichous on the branches of mature tree. Emerging leaves which were purplish red, later changed to dark green. The flowering season was from December to January. But development was completed in 28 days. Flowers were female and borne terminally on branchlets either singly or in groups of two to four. Flower drop was meager. Peak anthesis period was between 17.30 and 18.00 hours. Flowers had four scarlet red sepals and four yellow petals each having imbricate aestivation. Androecium consisted of 18-20 staminodes. Gynoecium was syncarpous with five to seven carpels having single ovule in each locule on axile placentation. Style was short and had a five to seven fid capitate stigma at its end. Anthers failed to dehisce until flower opening but a few showed signs of dehiscence after anthesis. Stigma showed no signs of receptivity. Anthers produced numerous non viable pollen grains which failed to germinate in vitro. Different methods of pollination had no effect on fruit set. Initial set was high but a fruit drop of 41 per cent occurred during first month. Though fruit development was parthenocarpic and seed development parthenogenetic, seeds produced were viable. Therefore, mangosteen can be considered as an obligate agamosperm where proembryos developing from integuments of embryosac mature into embryos. Pulp development took place from 42nd day onwards. Average weight of ripened fruit was 100 g. The percentage contribution of pulp towards total fruit weight at ripening stage was 33.00 per cent as against 62.30 and 4.70 per cent in the case of rind and seed, respectively. Chemical composition of pulp showed a decreasing trend. Total sugars, reducing sugars, non reducing sugars and sugar : acid ratio increased upto harvest. Season of harvest coincided with South West monsoon. Stage of harvest was identified as 90 days after fruitset. Such fruits ripened normally in two days at ambient temperature and showed no difference in quality as compared to that of tree ripened fruit. At this stage, 25 per cent of the fruit skin developed a purple colour and scar formed at the stalk end was smooth, without any exudation of gum. Mechanical injury should be avoided during harvesting and handling to save fruits from Transluscent Flesh Disorder. Yield varied from 650 to 3350 fruits/tree. Number of segments, which was same as that of stigmatic lobes, ranged from four to seven. However, number of viable seeds ranged from zero to three. Fruits caught in the rain were severely affected with gamboges, a disorder, which accounted to about 33.82 per cent fruit loss. Exudation of yellow gum from the rind was the characteristic symptom. The fruit pulp also became yellow, gummy, corky, bitter in taste and inedible. Biochemical analysis showed that ripened fruit contained water 76.57, protein 0.5, citric acid 0.32, total sugars 17.02, reducing sugars 3.22, non reducing sugars 13.80, nitrogen 0.28, phosphorus 0.01, potassium 0.13, calcium 0.01 and magnesium 0.24 on percentage basis. Sugar : acid ratio, TSS and ascorbic acid content was 53.18, 27.00 0brix and 5 mg/100 g, respectively. β carotene was only in traces. Fruits stored under refrigerated conditions showed no quality deterioration and fruit loss even after one month of storage. Fruits kept in bamboo baskets lasted for a fortnight. Keeping quality of fruits even without any treatment was more than a week. During storage TSS, sugars and sugar: acid ratio decreased, whereas acidity increased with the storage period. Seeds varied in size and shape. Viability was very high when sown immediately after harvest. Storage reduced the viability and was completely lost by 35 days of storage. Seeds took 20 days for germination. Germination was hypogeal with single seedlings arising normally, but 10 per cent polyembryony with 2-4 seedlings/seed was also noticed.

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