Browsing by Author "Narayanan Namboodiri, K M"

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Biological effects of gamma rays and EMS in the M1 generation of red gram(Cajanus cajan L.)
(Department of Agricultural Botany, College of Horticulture, Vellanikkara, 1986) Jayanthi, S; Narayanan Namboodiri, K M
Biological effects of gamma rays and EMS in the M2 generation of red gram (Cajanus cajan L.)
(Department of Agricultural Botany, College of Horticulture, Vellanikkara, 1987) Brenda Valentina Aranha; Narayanan Namboodiri, K M
The studies reported herein were undertaken in the Department of Agricultural Botany, College of Horticulture, Vellanikkara, during the period 1984-86. Seeds of the M1 generation of SA-1 variety of red gram (Cajan L.) which were initially subjected to induced mutagenesis using five doses of gamma rays (10, 20, 30, 40 and 50 ) and five doses of EMS (0.3 , 0.4, 0.5, 0.6 and 0.7per cent) were made use of to raise the M2 generation and their biological effects were studied. It was observed that in the chlorophyll mutation frequencyrestricted on M2 progeny row basis and M2 seedling basis , the pattern of change in the frequency in relation to dose was found to be the same not only for gamma rays but also for EMS. In case of both the mutagens the frequency did not appear to exhibit any dose relationship.
Biometrical studies in banana
(Department of Agricultural Botany, College of Horticulture, Vellanikkara, 1982) Rosamma, C A; Narayanan Namboodiri, K M
Studies were undertaken with forty eight banana varieties belonging to five different genomic groups at the Banana Research Station, Kannara and Department of Agricultural Botany, College of Horticulture, Vellanikkara during 1981-82 to estimate the extent of genetic variability, association among the selected characters and its partition into direct and indirect effects through path coefficient analysis. Selection indices were worked out to estimate the efficiency of selection through discriminant function over straight selection or vice versa.
Genetic analysis in red gram (Cajanus cajan L.)
(Department of Agricultural Botany, College of Horticulture, Vellanikkara, 1990) Achamma Oommen; Narayanan Namboodiri, K M
The research project "Genetic analysis in red gram" was carried out in the College of Horticulture, Kerala Agricultural University, Vellanikkara, Trichur during the period 1985-90. A 5 x 5 diallel cross, excluding reciprocals conducted in red gram revealed the predominance of additive gene effect for all the characters except days to first flowering. The combining ability analysis showed PLA-550 as the best general combiner; and the F 1 of the cross UPAS-120 x I.C. 15708 to have good specific combining ability. Negative heterosis over both the parents was exhibited by UPAS-120 x I.C. 15708 and PLA-550 x PLA-600 for days to first flowering and days to maturity which showed that early maturing segregants could be obtained from these crosses. The same crosses showed relative heterosis for yield also. The analysis of generation means by using six parameter model revealed the importance of both additive and dominance gene effects in the expression of most of the characters. Additive x additive and dominance x dominance effects showed influence in the expression of the characters. Among the components of variances dominance variance was higher for most of the characters. Heritability in narrow sense was found to be low. Number of clusters per plant and number of pods per plant were highly correlated with yield in parents, F 1 's and F2's. As the yield and yield components in the present study were under all the three types of gene action viz., additive, dominance and epistasis, reciprocal recurrent selection procedure seems to be the best suited method of breeding for improvement of this crop.
Genetic analysis of yield in banana
(Kerala Agricultural University, 1990) Rosamma, C A; Narayanan Namboodiri, K M
The forty eight banana varieties showed significant differences with reference to the 18 characters studied and a large portion of variability in all the characters except length of individual finger was due to genetic factors. Out of 17 characters studied, 13 showed strong correlation with bunch weight. Heritability estimates in the broad sense was high (over 80%) for eleven components and moderately high (65 to 80%) for all the rest except length of individual finger. Genetic gain was highest for weight of individual finger which recorded maximum direct effect on bunch weight. Characters like total number of fingers per bunch, number of hands per bunch, bunch length and girth at the base of pseudostem at shooting time have positive direct effect on bunch weight while, girth of individual finger, total number of leaves per plant and leaf area contributed mainly through other characters. Selection index formulated using characters such as bunch weight, number of hands per bunch, bunch length, total number of fingers per bunch and weight of individual finger was the most effective.
Genetic studies in cowpea
(Division of Agricultural Botany,College of Horticulture, Vellanikkara, 1979) Chandrika, P; Narayanan Namboodiri, K M
Geneticstudies were undertaken with 202 varieties of cowpea (Vigna ungulculata L.) maintained in the germplasm collection of the Division of Agricultural Botany, College of Horticulture, Vellanikkara. The studies conducted during the two khariff seasons of 1977-78 and 1978-79 were mainly directed towards estimation of the variability available in the collection, working out of the heritable components of the variability, identification of promising donor varieties for important characters and grouping the varieties into clusters according to the estimated genetic distances following the Mahalanobis D2-statistic.
Genetic studies in red gram (Cajanus cajan L.)
(Department of Agricultural Botany, College of Horticulture, Vellanikkara, 1988) Radhakrishnan, V V; Narayanan Namboodiri, K M
The research project “Genetic studies in red gram (Csjsnus csjsn h. Mill sp.)* wae carried out at the College of Horticulture, Kerala Agricultural University, Vellanikkara, Trichur during the period 1983-86. The genetic diversity studies among the 112 genotypes of red grans obtained from NBPGR, Vellanikkera and THAU, Coimbatore during 1963-84 showed that the genotypes of the same place of origin fell into different clusters while those of diversified origin fell into seme cluster. All the genotypes studied were grouped into five clusters. Based on both the inter and intr©cluster distances 20 genotypes representing the broad spectrum of variability were selected and raised during 1965-86. The values estimated for phenotypic coefficient of variation and genotypic coefficient of variation showed that number of clusters per plant, number of pods per plant and seed yield possessed high estimates. Number of days from sowing to 50 per cent flowering and seed yield have exhibited high heritabllity coupled with moderately high genetic gain estimate* indicating the involvement of additive gene effect* Ku:ber of days from sowing to harvest and height of plant at harvest, have high or moderately high estimates of heritability together with low values of genetic gain indicating the action of non-additive genes. In nine out of ten cases there has been significant positive correlation between component characters and seed yield both in the phenotypic and genotypic levels, however the correlation of hundred seed weight with seed yield was not significant both at phenotypic and genotypic levels* Intercorrelaticna studies have shown that characters exhibiting significant association with seed yield per plant were also highly intercorrelated indicating that these characters can be simultaneously improved. Path coefficient analysis showed that number of poda par plant, hundred seed weight, number of primary branches at harvest, number of secondary branches at harvest and length of pod bearing branches had high positive direct effects on seed yield in th at order* The residual effect wea 0*07227 indicating that about 93 per cent of the variation in yield were contributed by the ten components considered in path coefficient analysis. The selection index formulated with characters like seed yield, number of pods per plant and hundred seed weight showed an efficiency of 8.4 per cent over direct selection and it includes 57 per cent of the factors determining the yield. Hence it is suggested for isolating superior genotypes. A comparison of different genotypes based on the index value has revealed the superiority of the genotypes NSPGR-XX-EC—10046-1 and HBPGR-124-PLA-345-1 over others. The study paved the way for understanding the source of variability for various factors contributing to yield, the degree of diversity among the genotypes, on the association between yield and its components and between themselves, and helped to formulate selection index for selecting superior genotypes.
Genetic studies in red gram (eafanui caiaixL)
(Department of Agricultural Botany, College of Horticulture, Vellanikkara, 1988) Radhakrishnan, V V; Narayanan Namboodiri, K M
Genomic relationship in Vigna species
(Department of Agricultural Botany, College of Horticulture, Vellanikkara, 1986) Neema, V P; Narayanan Namboodiri, K M
Investigations on the genomic relationship in Vigna species were undertaken in the Department of Agricultural Botany, College of Horticulture during 1983-1985. Pure seeds of the two subspecies of Vigna unguiculata, viz. unguiculata and sesguipedalis were sown and crop raised. Direct and reciprocal crosses were made. Morphological and cytological investigations were done. It was found that the two subspecies easily crossable. In both the subspecies there was high prefertilisation shed. The chromosome number of subsp. unguiculata was 2n=22, of subsp. sesguipedalis 2n=24 and of F1 hybrid was 2n= 23. Both the parents and hybrid showed cells with laggards. Length of meiotic and somatic metaphase chromosomes was more in subsp. sesguipedalis, lowest in subsp. unguiculata and intermediate in their F1 hybrid. Both the subspecies and their hybrid had almost similar TF % which gave an indication of similarity in their karyotypes. Pollen fertility was more in subsp. sesguipedalis. Reciprocal difference was seen in the case of morphological characters like height of the plant, number of primary branches, internodal length, seeds per pod, seed colour and seed volume. However, these differences were not seen traceable in the cytology of the hybrid.
IC divergence in coconut
(Department of Agricultural Botany, College of Horticulture, Vellanikkara, 1982) Balakrishnan, P C; Narayanan Namboodiri, K M
A study was conducted at the Regional Agricultural Research Station, Pilicode and in the College of Horticulture, Vellanikkara during 1981-82 with the objectives of assessing the extent of variability present in the 24 cultivars of coconut maintained in the germplasm collection at Pilicode and to assess their genetic divergence using Mahalanobis D2 statistic. All the 24 cultivars were planted during 1924-25, and hence were of the same age group and were receiving the same management practices. Observations on 17 economic characters were recorded from 120 palms at the rate of 5 palms per cultivar. Four observations at quarterly intervals were recorded during the 12 month period of study. The data were subjected to relevant statistical analyses and the results were interpreted.
Investigations on intervarietal F2 hybrids in cowpea
(Department of Agricultural Botany, College of Horticulture Vellanikkara, Trichur, 1981) Sumathikutty Amma, B; Narayanan Namboodiri, K M
Pollination studies in cashew
(Department of Agricultural Botany, College of Horticulture, Vellanikkara, 1985) Elsy, C R; Narayanan Namboodiri, K M
Investigation on the various aspects of pollination viz., flower opening, fruit set and fruit drop under natural pollination and assisted pollination, effect of pollinating agents and intensity of pollen in the atmosphere were undertaken at the Cashew Research station, Madakkathara and Department of Agricultural Botany, College of Horticulture, Vellanikkara during 1983-84, on six year old BLA-139/1 trees (air layers) under uniform cultural and manurial conditions. The data were subjected to various statistical analysis. The results have shown that the period of flower opening in both male and hermaphrodite flowers was same, starting after 23 hr and extending upto 15 hr next day. The peak period of flower opening for male flowers was between 7 and 9 hr and for hermaphrodite flowers between 9 and 11 hr. Climatic factors such as temperature, sunshine hours, relative humidity and wind velocity have not shown any significant influence on the magnitude of flower opening. Type BLA-139/1 has a relatively low sex-ratio of 1: 2. 83 resulting a higher percentage of hermaphrodite flowers. There is variation in sex-ratio even within the panicles of the same tree. When compared to natural pollination, assisted pollination resulted in significantly higher initial fruit set indicating the inefficiency or inadequacy of pollinating agents. But the higher initial fruit set was not fully reflected in the percentage of fruits harvested since a major portion of the set fruits dropped at different stages of development. In both cases of natural and hand pollination, fruit droop was more in early stages of nut development. This necessitates the need for improving the initial fruit set and more over reducing post fertilization drop for higher yields in cashew. In completely bagged panicles no fruit was set, confirming the cross pollinated nature of cashew. The failure of fruit set in water sprayed panicles rules out the possibility of water as a pollinating agent. Wind plays a significant role in cashew pollination along with insects like red and black ants, honey bees and butterflies which frequently visit cashew inflorescence. The intensity of pollen grains on the atmosphere was 20 times higher than that of hermaphrodite flowers in a unit area.
Seed dormancy in groundnut
(Department of Agricultural Botany, College of Horticulture, Vellanikkara, 1992) Presanna Kumari, K T; Narayanan Namboodiri, K M
The present investigation entitled "Seed dormancy in groundnut" was undertaken in the Department of Agricultural Botany, College of Horticulture, Vellanikkara during 1987-1990 using the 419 genotypes received from ICRISAT, Hyderabad. The 419 genotypes possessed varying levels of dormancy at the time of harvest. Genotypes with varying degrees of dormancy were present in all the three botanical groups, viz., hypogaea, fastigiata and vulgaris. The dormancy period of genotypes ranged from 20 to 110 days. The hypogaea genotypes required longer period of rest. The nature of breakage of dormancy and the period of dormancy were found to be two independent phenomena. The factors for dormancy in groundnut were found to be residing in two distinct sites, the cotyledons and the seed coat (testa). Leaching improved the germinability of decoated seeds where as it failed to elicite germination in intact seeds. This indicates that germination inhibitors may be present in the cotyledons and testa retarded the removal of the same. Different genotypes responded differently to various presowing treatments. HgCl2 1, 1000 for five minutes was found to be the best treatment for breaking dormancy. The study of germinability of F1,F2 and F3(embryonic generation) seeds on the day of harvest indicated that dormancy was controlled by polygenes.
Studies on intervarietal hybrids in cowpea
(Division of Agricultural Botany, College of Horticulture, Vellanikkara, 1980) Inasi, K A; Narayanan Namboodiri, K M
Among the green vegetables cultivated in Kerala, cowpea (Vigna ungulculata L.) occupies about 70 per cent of the total area. At present cowpea cultivation in the state is showing a declining trend due to the low productivity of the available local varieties. The highly contrasting systems of cultivation of cowpea in the various parts and in different seasons in the State compels compels cowpea breeders to evolve varieties of different combinations of plant, pod and seed characters. This is possible by combining of desirable characteristics found distributed in different varieties, through hybridisation followed by selection.
Studies on the mechanism of seed dormancy in rice
(Kerala Agricultural University, Vellanikara, 1968) Narayanan Namboodiri, K M
Variability in inter varietal hybrids and open pollinated seed progenies of black pepper ( Piper nigrum L .)
(Department of Agricultural Botany, College of Horticulture, Vellanikkara, 1991) Sujatha, R; Narayanan Namboodiri, K M
Variability studies in cowpea
(Department of Agricultural Botany, College of Horticulture, Vellanikkara, 1981) Jalajakumari, M B; Narayanan Namboodiri, K M
Studies were undertaken with seventeen cowpea varieties representing seventeen clusters, in the Department of Agricultural Botany, College of Horticulture, Vellanikkara during 1979-80 to estimate the extent of genetic variability, association among the selected characters and its partition into direct and indirect effects through Path Coefficient Analysis. A discriminant function analysis was carried out with a view to isolating superior genotypes from among those studied.