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ThesisItem Open Access Divergence studies in pumpkin (Cucurbita moschata Pair)(Department of Olericulture, College of Horticulture, Vellanikkara, 1989) Suresh Babu, V; KAU; Gopalakrishnan, T RThe present investigation on "Divergence studies in pumpkin (Cucurbita moschat a Poir ) was conducted at the College of Horticulture , Vellanikkara, Trissur during June 1988 - Marc h 1989. Seventy one pumpkin genotypes collected from different part of India and abroad were utilized for the study. The extent of variability and divergence among 50 selected genotypes were assessed and grouped into 5 clusters based on Mahalanobis D2 statistic . Cluster I, II, III, I V and V contained 2, 7, 9, 12 and 20 genotypes respectively y . Intercluster distance was maximum between clusters I and II and was minimum between clusters III and V . Cluster I showed maximum average intercluster distance with any other cluster. Screening 71 genotypes for resistance/ tolerance to pumpkin mosaic and yellow vein mosaic diseases revealed that all genotypes except C M 214 were susceptible. Artificial inoculation studies confirmed immunity of C M 214 (Nigerian Iocal ) to pumpkin mosaic virus and yellow vein mosaic virus .ThesisItem Open Access Homeostatic analysis of components of genetic variance and inheritance of fruit colour, fruit shape and bitterness in bitter gourd (Momordica charantia L.)(Department of Olericulture, College of Horticulture, Vellanikkara, 1989) Abdul Vahab, M; KAU; Gopalakrishnan, P KThesisItem Open Access In vitro studies on the propagation of cardamom (Elettaria cardamomum maton)(Department of Plantation Crops and Spices, College of Horticulture, Vellanikkara, 1989) Reghunath, B R; KAU; Gopalakrishnan, P KThesisItem Open Access Standardization of growing media for dendrobiums (Qendkobium dpp.)(Department of Horticulture, Pomology & Floriculture and Landscaping, College of Horticulture, Vellanikkara, 1989) Anitha, Paul C; Rajeevan, P KThesisItem Open Access Physiological investigations in relation to flowering, fruit set and capsule developmentj of cardamom (elettaria cardamomum maton)(Department of Plantation Crops and Spices, College of Horticulture, Vellanikkara, 1986) Vasantha Kumar, K; KAU; Mohanakumaran, NInvestigations were carried out at the Cardamom Research Station, Pampadumpara and at the College of Horticulture, Vellanikkara during 1982 – ’84 to gather information on the physiological factors governing flowering, fruit set and capsule development of the three popular cardamom cultivars, Malabar, Mysore and Vazhukka. Emphasis had been given to unravel the causes of fruit (Capsule) shedding so as to evolve methods of control. Studies on growth and development in a broad sense depicted that an individual tiller of cardamom had a biennial growth habit. The different aspects of flowering and fruit set studied. Indicated that the variability was high in the Vazhukka cultivar and low in the Mysore cultivar. An early crop bearing habit was exhibited by Malabar, whereas Mysore possessed a late bearing habit and Vazhukka exhibited varying trends. The percentage of fruit set was high in Vazhukka, followed by Malabar and Mysore. Influence of climatic components on the physiology of flowering showed that a distinct dry spell triggered the panicle initiation process. The onset of rain coupled with high temperature was congenial for flower opening. A high soil moisture status combined with a high status of relative humidity (which resulted from a well distributed rainfall) enhanced the setting of capsules. Histological studies conducted in the genotype PV-1 (Malabar) showed that differentiation of panicle primordial was more during November to March. A prominent vascular zonation was observed in the rhizome nodes prior to the initiation of panicle promordia. Histology of the seeds revealed the development of starch grains at the greenish- yellow seed stage. Biological assays for endogenous auxins, inhibitors and cytokinins in the developing capsules indicated a spurt in auxin and cytokinin activity preparatory to fruit set. The level of inhibitory substances rose after the fruit set stage, while that of auxins fell which favoured the formation of an abscission zone causing shedding of immature capsules. Exogenous application of NAA (40 ppm) and 2, 4-D (4 ppm) increased the plant height, enhanced the production of panicles and flowers, reduced dropping of immature capsules and increased the yield. The uptake of nutrients revealed that cardamom is a heavy feeder of potash. The Vazhukka and Malabar cultivars developed less nutrients than the Mysore cultivar for producing unit yield of capsules. Radiotracer studies showed that the photosynthetic efficiency of cardamom was more under low light intensities. The rhizome was found to be the main sink in a cardamom tiller. Gas chromatographic estimation of cardamom oils indicated that the Mysore genotype (PR-107) was superior in quality aspects (because of high content of the esters, alpha terpenyl acetate, geranyl acetate and linalyl acetate) when compared with the Vazhukka genotype (PV-5) and Malabar genotype (PV-1). For consumption as a spice as well as for distillation of the essential oils, the black seed stages (‘karimkai’) was the most idel stage in cardamom.ThesisItem Open Access Evaluation of a set of non-segragating and segragating populations of tomato for field resistance to bacterial wilt(Department of Olericulture, College of Horticulture, Vellanikkara, 1985) NarayananKutty, C; KAU; Peter, K VBacterial wilt caused by Pseudomonas solanacearum E.F. Smith is the single limiting factor for tomato cultivation in the warm humid tropical soils of Kerala. The susceptibility of reportedly resistant varieties elsewhere necessitates the need for continuous evaluation of tomato lines for wilt resistance. An experiment was planned and carried out during 1983-’85 at the College of Horticulture, Vellanikkara to identify new sources of resistance to bacterial wilt. The susceptible check Pusa Ruby showed 100% susceptibility in all the trials. The F2 hybrids of Saturn and LE 79 were found resistant, out of the four non-segregating (Saturn, LE 79, Pusa Ruby and Pusa Ruby x LE 79 F1) and two segregating populations (Pusa Ruby x LE 79 F2, Saturn x LE 79 F2) evaluated. In a repeated trial F3s were also evaluated along with the F2s and non-segregating populations (Saturn and FE 79). Resistance was observed in Saturn x LE 79 F3 (percentage wilt, 10.7) and Saturn x LE 79 F2 (percentage wilt, 18.23). Pusa Ruby x LE 79 F2 s and F3s were susceptible to moderately susceptible. Among the non-segregating populations, LE 79 showed moderate resistance, while Saturn was moderately susceptible to susceptible in both the trials. Information on days to fruit set, days to harvest, fruit yield/plant and average fruit weight were also gathered. A higher average fruit weight (44.63g) was observed in the resistant Saturn x LE 79 F3s. Evaluation of 15 reportedly resistant lines of tomato confirmed resistance in LE 79 LFG and LE 217. The line LE 79 LFG was also medium fruited (40.1g) and high yielding. Concentric cracking and irregular cracking were observed higher than radial cracking in all the lines evaluated. Fruit set ranging from 50 to 63% was observed in all the lines at higher night temperatures (230C average). Genetics of fruit shoulder colour revealed that white colour was recessive to green and governed by a single gene. Evaluation techniques like root dipping in bacterial culture and planting, stem inoculation in leaf axil and alternate row planting were compared with spot-planting for efficiency. Spot-planting was found easier and effective. The chances for escape are negligible in this method of evaluation.ThesisItem Open Access Radiation induced variability in interspecific hybrids involving abolmoschus esculentus moench and abolmoschus manihot(Department of Olericulture, College of Horticulture, Vellanikkara, 1986) Dalia Cherian; KAU; Peter, K VYellow vein mosaic is the most destructive viral disease of bhindi, which takes heavy toll of the crop, infecting at all growth stages. Attempts to isolate source(s) of resistance to yellow vein mosaic disease from cultivars and wild relatives were proved to be of limited success because of either incompatibility or sterility barriers between the cultivars and wild relatives. An experiment was planned and carried out during June - October,1984; November - April, 1984-'85 and June - October 1985 at the Instructional Farm _ of the College of Horticulture, Vellanikkara, Trichur to induce variability in interspecific hybrids involving Abolmoschus esculetus (L.) Moench and Abolmoschus manihot (L.) Medic. The three accessions of Abolmoschus manihot were observed cross compatible with Abolmoschus esculentus cv. ‘Pusa Sawani', Abolmoschus menihot sap, tetraphyllus crossed readily with abolmoschus esculentus (Cl = 95%) . This was proved through Fo fruit set, Fo seed set and germination of F0 seeds. The F1 plants did not bear normal seeds and F2 generation could not be raised. The pollen fertility of F1 hybrids were much lower than the parents. There was reciprocal difference in the crossability index. radiation created considerable variability in interspecific F1 hybrids for days to flower, plant height,leaf length, leaf width, fruit length, fruit girth, nodes on main stem, fruiting nodes on main stem, intemodal length, fruits/plant, ridges/fruit and fruit yield/plant, in Abolmoschus esculentus x 2 accessions of Abolmoschus manihot. There was preponderance of characters of Abolmoschus manihot in the interspecific hybrids. Considerable changes in discrete characters were observed in irradiated F1 hybrids. Dominant characters like branched habit, pubescence and pigmentation of vegetative parts, and hairiness of fruit got changed with gamma radiation. Though the radiation enhanced the pollen fertility of interspecific hybrids, they had seedless fruits or fruits with incompletely filled seeds. With the doses 15 kR, 20 kR and 25 kR tried, quantitative and qualitative characters were affected, though there appeared to be scope for the use of still higher dose of rays to create wider variability in interspecific hybrids. Under natural field conditions and artificial inoculation, ‘Pusa Sawani’ was infected by yellow vein mosaic virus, whereas none of the wild species did exhibit any symptoms. Artificial inoculation provides a means to select desirable plant types having resistance to yellow vein mosaic disease.ThesisItem Open Access Pattern of root activity in bananas under irrigated and rainfed conditions(Department of Pomology and Floriculture, College of Horticulture, Vellanikkara, 1985) Sobhana, A; KAU; Aravindakhan, MThe experiments were undertaken with an objective to find out the most active root zone of banana var. ‘Nendran’ employing radioactive 32p. These were conducted in the College of Horticulture, Kerala Agricultural University, Vellanikkara, during the year 1983-84. The field experiments were laid out in randomised block design, with three replications and the plants were raised under normal conditions. While taking into consideration the number, length and diameter fresh and dry weights of roots, all these were found to be more for the rainfed crop than the irrigated. This explains the enhanced production of roots under conditions of moisture stress. The radioactivity was injected at four months ago of the plant. The area around each experimental plant was injected with 32p solution with the help of a dispensette. The different lateral distances used for the 32p injection were 20cm, 40cm, 80cm and 120 cm and the different depths were 5cm, 15 cm , 30cm and 60cm. The third leaf was radio assayed and the 32p counts were used for finding out the percentage of active roots at the various treatment sites. The results of radiotracer studies indicated that maximum percentage of active roots was located at a soil zone covering 20cm distance and 30 cm depth from the base of the plant under irrigated condition, at five and six months age of the plant. The rainfed crop had its maximum percentage of active roots at a soil zone of 30cm deep and 40cm away from the plant. As the lateral distances increased from 20cm to 120cm, a reduction was noticed in the percentage activity of roots accordingly, under both irrigated and unirrigated conditions. But the root activity was not significantly different at different depths for the irrigated crop, which was significant for the rainfed crop. Under high moisture stress roots tend to forage into deeper layers of soil for getting the available water. Hence deeper soil zones had more active roots under unirrigated conditions, compared to irrigated crop, which had more surface active roots. An experiment was also organized to study of the translocation of absorbed 32p to various parts of the plant after flowering under irrigated condition. It was observed that male flowers had maximum concentration of 32p followed by female flowers or fruits. Of the various leaves, topmost younger leaves were found to build up more 32p than matured leaves, indicating a translocation to the developing immature leaves.ThesisItem Open Access Phenotypic stability analysis in bacterial wilt resistant lines of brinjal (Solanum melongena L.)(Department of Olericulture, College of Horticulture, Vellanikkara, 1987) Ushamani P, P; KAU; Peter, K VTwenty six genotypes of brinjal (Solanum melongena L.) were grown continuously in two seasons each under two contrasting environments in a randomised block design. Observations were recorded on yield and seven of its component characters. Significant variations among the genotypes were observed. G x E interaction was significant for plant height, primary branches/plant, percentage of productive flowers, fruits/plant, average fruit weight and yield/plant. The 26 lines were classified as suited to low, medium and high yielding environments. SM 6-6 M, SM 6-4 PL and SM 6-2 SP were suited to average environments; SM 6-6 PL and SM 6-3 SP suited to high yielding environments and SM 6-8PL and SM 6-1 SP suited to low yielding environments. The path analysis revealed fruits/plant and primary branches/plant having maximum direct effect on yield. The 26 lines were grouped into 4 clusters in each environment based on Mahalanobis D2 statistics. The intra and inter cluster distances and genotypes within clusters differed in the four trials. The stable lines were moderately resistant to bacterial wilt. They had root galls caused by Meloidogyne incognita. Root volume was positively correlated with yield. Survey conducted on preference to color and shape showed that white long and purple long fruits were the most preferred. The stable brinjal lines possessed this economic value also.
