Browsing by Author "Manikantan Nair, P"

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Combining ability in okra (Abelmoschus esculentus [L.] Moench)
(Kerala Agricultural University, Vellanikara, 2001) Rajani, B; Manju, P; Manikantan Nair, P; Saraswathy, P
A study was conducted to estimate the combining ability of six genetically divergent parental strains of okra by diallel analysis with respect to yield and a few related attributes. The combining ability analysis by the Method I of Griffing's (1959) approach revealed that the parent NBPGR/TCR 861 was the best general combiner for single fruit weight and length and NBPGR/TCR 864 for yellow vein mosaic resistance. Among hybrids, NBPGR/TCR 893 x NBPGR/TCR 864 exhibited outstanding sea effect for yield while NBPGR/TCR 865 x NBPGR/TCR 438 and NBPGR/TCR 893 x NBPGR/TCR 861 were notable for single fruit weight, length and girth. The hybrid NBPGR/TCR 854 x NBPGR/TCR 865 showed maximum tolerance to YVM.
Correlation studies in black gram under partially shaded conditions
(Kerala Agricultural University, 1992) Saji T Abraham; Sreekumar, S G; Saraswathy, P; Gopinathan Nair, V; Manikantan Nair, P
Cytological studies on four inter varietal crosses of capsicum annuum
(Kerala Agricultural University, 1975) Manikantan Nair, P; Mary K George
Cytological studies of microsporocytes in four hybrids and five parents of the varieties of Capsicum annuum were conducted. Variety local blue was taken as the seed parent. The pollen parents Included varieties, Russian, Indian long red, Chinese g-'ant and Oskosh. All the four crosses revealed pronounced heterosis as regards pollea size. Further, all the hybrids manifested the presence of ring quadrivalents, chain quadrivalents, and trivalents while the hybrid local blue x Indian long red contained univalents, pycnotic behaviour, unequal distribution and anaphase bridges. The abnormal meiotic behaviour of microsporocytes had a positive correlation on the pollen sterility and affected the ultimate fruit set.
Cytomorphological and chemical studies on intervarietal crosses of Capsicum annuum, L.
(Division of Agricultural Botany, Agricultural College & Research Institute, Vellayani, 1970) Manikantan Nair, P; Mary K George
1. The cytomorphological and chemical aspects of four F1 hybrids of crosses involving five varieties of Capsicum annuum L. were studied . The variety ' Local blue' which possessed mosaic resistance , prolific bearing habit , long life span and high pungency was selected as the common seed parent. The selected pollen parents were, Russian, Indian long red , Chinese giant and Oskosh which were gifted with a higher content of ascorbic acid and sucrose and larger fruit size , but lacking the qualities of the common seed parent. 2. All the four F1 hybrids manifested a marked degree of heterosis in many economically important attributes like , carliness in blooming, number of leaves, number of branches, leaf area and chemical constituents like ascorbic acid and sucrose. 3. An intermediate condition was observed with regard to height , spread, number of fruits, fruit size and number of F2 seeds
Effect of growth regulators on the yield of tomatoes
(Kerala Agricultural University, 1974) Manikantan Nair, P; Mohanakumaran, N; Ramachandran Nair, V
Estimation of heterosis in bhindi [Abelmoschus esculentus (L.) Moench]
(Department of Plant Breeding, College of Agriculture, Vellayani, 1984) Balachandran, P V; Manikantan Nair, P
Evaluation of bhindi hybrids for yield and its components
(Department of Plant Breeding, College of Agriculture, Vellayani, 1986) Sheela, M N; Manikantan Nair, P
Evaluation of the productivity of chilli hybrids
(Department of Plant Breeding, College of Agriculture, Vellayani, 1986) Elizabeth Philipose; Manikantan Nair, P
A study was conducted at College of Agriculture, Vellayani, for evaluating the productivity of six intervarietal chilli (Capsicum annuum L.) hybrids obtained by crossing four inbreds in all possible combinations without reciprocals. Since the germination of the combination PR x PCl was poor, the other five hybrids along with four parents were evaluated in a 9 x 3 RED during 1984-85 and 1985-86. Observations on twenty quantitative and five five qualitative attributes were recorded. The statistical analysis included analysis of variance , pooled analysis and the estimation of genetic parameters, correlations among sixteen quantitative traits and three types of heterosis namely relative heterosis, heterobeltiosis and standard heterosis
Genetic analysis of biological nitrogen fixation traits and yield components in cowpea (Vigna unguiculata (Linn). walp)
(Department of Plant Breeding and Genetics, College of Agriculture, Vellayani, 1995) Sreekumar, K; Manikantan Nair, P
Genetic evaluation of M2 V1 guinea grass (Panicum Maximum Jacq) clones under partially shaded conditions
(Department of Plant Breeding, College of Agriculture, Vellayani, 1991) Santhi Priya, G; Manikantan Nair, P
The top ranking ten clumps from the open pollinated seed progeny of each of the four mutant clones of guinea grass variety FR - 600 viz., MC - 2, MC - 14, MC - 16 and MC-23 and two control varieties FR – 600 and Makueni were studied in terms of green fodder yield, dry matter yield, tiller count and root length and were evaluated to identify genetically superior clones. The six clones comprising of 60 progenies were evaluated in a field trial in a compact family block design with four replications. Analysis of variance carried out for ten characters revealed significant differences among the six families for seven characters. The familywise analysis of variance carried out displayed significant differences among the progenies in either one or more of the families for eight out of the ten characters, indicating that sexual reproduction is prevalent in the crop at least to some extent. As genetic variability existed within the families, selection will be effective within the families too. Genotypic coefficient of variation was maximum for inflorescence count and minimum for height of grasses. High heritability estimates were recorded for inflorescence count, height of grasses and free proline content of leaves, indicating that its genetic improvement can be effected through selection. Moderate heritability values were recorded for root length, leaf area and dry matter yield while tiller number. Leaf/stem ratio, green fodder yield and reaction to collar rot recorded low heritability values. Genetic advance expressed as percentage of mean was high for free proline content of leaves and inflorescence count and low for all the other characters. A selection index based on plant height, tiller number, leaf area, leaf/stem ratio and green fodder yield identified six of the progenies as genetically superior from among the sixty progenies studied, when ten per cent selection was exercised. The top ranking six progenies belonged to the families MC – 23 and Makueni.
Genetic evaluation of pre-release cultures and varieties of rice for yield, sheath blight and sheath rot diseases
(Kerala Agricultural University, 1992) Sreekumar, S G; Gopinathan Nair, V; Balakrishnan Asan, R; Manikantan Nair, P
Genetic variability and correlations in sugarcane hybrid clones
(Kerala Agricultural University, 1993) Alice Antony; Manikantan Nair, P; Gopinathan Nair, V
A field trial with selected sugarcane hybrid clones of the intervarietal cross Co 775 x Co 453 was conducted at the Sugarcane Research Station, Thiruvalla to study the different genetic parameters in the settling progeny. High heritability was observed for shoot count, total weight of cane, number of miIIable canes, length of internode, length and girth of cane and weight of single cane at harvest. Cane yield and its components displayed low coefficients of variation. Correlation studies indicated that cane yield has positive correlation with all majoreconomicaltributes except U.K. Brix. The closest association of cane yield with number of millablc canes at harvest was well established with the present study. The study suggested that probabilities of varieties combining higher yield and quality attributes are remote.
Heterosis in bhindi
(Kerala Agricultural University, 1988) Sheela, M N; Manikantan Nair, P; Gopinathan Nair, V
Six parents and their six hybrids were evaluated during 1984-'85 on the basis of percentage of heterosis manifested by them for yield and its components. All the hybrids displayed desirable heterosis for the major economic characters such as weight of fruits per plant, number of fruits per plant etc. Negative heterosis was exhibited by the hybrids for crude fibre content, the most important quality attribute in bhindi. The results suggested that heterosis breeding could be effectively employed in augmenting the yield potential and allied attributes in bhindi. The present study could identify two hybrids Selection 2-2 x Kilichundan and Sevendhari x Kilichundan with high yield potential coupled with other desirable attributes. The hybrids, Selection 2-2 x Kilichundun and Sevendhari x Kilichundan have out yielded the standard cultivar, Pusa Sawani, by 65.06 percent and 50.34 per cent respectively. Both the hybrids produced large number of long heavy fruits with good thickness and low crude fibre content. These hybrids will go a long way in boosting up the production potential of bhindi in homestead and commercial cultivations.
Heterosis in chilli (Capsicum annum L.)
(Kerala Agricultural University, 1986) Manikantan Nair, P; Mary K George; Mohanakumaran, N
An experiment was laid out in 1979 at the Department of Agricultural Botany, College of Agriculture, Vellayani to study the heterosis in Capsicum annum L. Nine parents and 36 F1 hybrids were compared. Eighteen economic attributes including vitamin A, vitamin C, capsaicin and oleoresin content were studied. All the characters under investigation manifested heterosis over midparental values though there was wide variation for different traits in different cross combinations. Maximum heterosis was noticed for number of primary bradches and vitamin C content. A comparison of average heterosis for various characters revealed that number of secondary branches topped the list followed by vitamin C, capsaicin content and number of primary branches. The studies identified two promising hybrids with desirable attributes namely Purple Round x Vellanotchi and Pant C1 x Purple Cluster. Negative heterosis was noticed for two important economic attributes namely number of days taken for blooming and number of seeds per fruit. For nutritive and quality characters very little expression of hybrid vigour in vitamin A content was noticed. However, there was considerable manifestation of hybrid vigour in vitamin C and oleoresin content.
Induction of genetic recombinations in interspecific crosses of Abelmoschus
(Department of Plant Breeding and Genetics, College of Agriculture, Vellayani, 1994) Sheela, M N; Manikantan Nair, P
A study was undertaken at the College of Agriculture, Vellayani during 1990-91 aimed at inducing recombinations of the economic attributes of Bhindi (Abelmoschus esculentus (L.) Moench) and the yellow vein mosaic disease resistance of wild relatives. A preliminary evaluation of 56 accessions revealed good genetic diversity in Bhindi germplasm. The accessions were grouped into four clusters. The characterization of germplasm was done based on IBPGR descriptors. High genotypic coefficients of variation were exhibited by weight of fruits per plant, leaf area, height of plant, number of fruits per plant, single fruit weight and number of branches per plant indicating scope for selection. High heritability along with high genetic advance was recorded for weight of fruits per plant, height of plant, leaf area and number of seeds per fruit. Low heritability coupled with low genetic advance recorded for yellow vein mosaic disease incidence indicated the predominant role of environment in the inheritance of disease resistance.
Interspecific cross- compatibility in the genus Abelmoschus
(Department of Plant Breeding, College of Agriculture, Vellayani, 1993) Sindhu, S; Manikantan Nair, P
Interspecific cross – compatibility in the genus Abelmoschus was undertaken with the objective of probing into the reasons of low fruit and seed set in the interspecifc hybrids of Abelmoschus which may pave the way for the development of yellow vein mosaic resistant varieties through recombination breeding. Crossing was done between the local cultivar Abelmoschus esculentus var. Anacomban and two semi wild species (A. manihot and A. manihot ssp. Tetraphyllus). The fruit set in direct crosses of A. esculentus var. Anacomban x A. manihot and A. esculentus var. Anacomban x A. manihot ssp. Tetraphyllus was very low compared to the reciprocal crosses, exhibiting partial incompatibility consequent on the slow pollen tube growth of A. manihot and A. manihot ssp. tetraphyllus. The seed set was low in crossed fruits and there was recovery of shriveled seeds which may be attributed to the poor endosperm development. The crossed seeds exhibited good viability. All the hybrids exhibited field tolerance to yellow vein mosaic disease. The four hybrids recorded pollen sterility which may be attributed to meiotic abnormalities, due to difference in chromosome number between the species. The seed set in the hybrids was very low. The seed set was inversely proportional to pollen sterility. The lower the pollen sterility higher was the seed set. The F2 seeds showed reduction in seed weight which may be due to high seed sterility exhibited by the hybrids. The recovery of empty seeds which appeared normal may be ascribed to endosperm degeneration. The seed viability of F2 seeds was very low. The result leads to the conclusion that the reason for low fruit and seed set in interspecific hybridization in Abelmoschus may be due to partial incompatibility. The interspecific hybrids displayed hybrid sterility which may be attributed to the meiotic abnormalities consequent on the difference in the chromosome number between the parents. However, all the hybrids were not completely sterile. The hybrids exhibited field tolerance to yellow vein mosaic disease which is an added advantage. Back crossing the F1 as the seed parent to the A. esculentus var. Anacomban may overcome the hybrid sterility and pave way for the development of varieties with yellow vein mosaic resistance coupled with economic attributes of the popular cultivar Anacomban.
Path analysis for harvest index in black gram
(Kerala Agricultural University, 1992) Saji T Abraham; Sreekumar, S G; Saraswathy, P; Gopinathan Nair, V; Manikantan Nair, P
Performance of cowpea varieties under varying levels of phosphorus in red-loam soils
(Kerala Agricultural University, 1976) Mohamed Kunju, U; Ramachandran Nair, V; Manikantan Nair, P; Sadanandan, N
Studies on four intervarietal crosses of Capsicum annuum with references to chemical constituents
(Kerala Agricultural University, 1973) Manikantan Nair, P; Mary K. George
Studies on genetic parameters and association of yield and its components in short duration tapioca varieties (Manihot esculenta Crantz-)
(Department of Plant Breeding, College of Agriculture, Vellayani, 1987) Rekha, V R; Manikantan Nair, P