Browsing by Author "Rosamma, C A"

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Adaptability and acceptability components of the rice cultivar kunjukunju
(Kerala Agricultural University, 1995) Elsy, C R; Sukumara Dev, V P; Rosamma, C A; Rajan, K M; Nadarajan, L
Aryan muthal aiswarya vare /ആര്യൻ മുതൽ ഐശ്വര്യ വരെ
(Kerala Agricultural University, 1993-07) Rosamma, C A; Elsy, C R; Rajan, K M
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.
Breeding for photosensitive high yielding rice variety
(Kerala Agricultural University, 1994) Rosamma, C A; Elsy, C R
An ideal rice variety with high gram and straw yield, adaptability to the rabi season and consumer preference was evolved at the Regional Agricultural Research Station, i'attambi from the cross between Co 25, Triveni and Vellathil Kolappala. This variety called Niln (Ptb 48) combines in itself high grain and straw yield under average management conditions, adaptability to the season and tolerance to most of the pests and diseases.
Character association in ratoon crop of rice (Oryza sativa L.)
(Kerala Agricultural University, Vellanikara, 2002) Ambili S, Nair; Rosamma, C A
The present investigation was carried out with 24 rice genotypes, which exhibited ratoon performance. Observations recorded on various characters were subjected to correlation and path analysis. The characters viz. number of productive tillers plant'1, straw yield, total number of tillers during flowering, and LAI (flowering) were found to be the major contributing characters towards ratoon yield.
Convergent breeding for new plant type in rice(Oryza sativa L.)
(Department of Plant Breeding and Genetics, College of Horticulture, Vellanikkara, 2005) Divya Satheesh; Rosamma, C A
The present study on “Convergent breeding for new plant type in rice (Oryza sativa L.) was carried out under the Department of Plant Breeding and Genetics, College of Horticulture, Kerala Agricultural University, Vellanikkara. This study was carried out for 23 characters in six lines and four testers, and their hybrids developed through a line x tester mating design and was aimed at identification of donor parents for the development of new plant type, and evaluation of the nature of gene action involved in the expression of quantitative traits. In the experiment combining ability, heterosis, character association and gene action involved were estimated. The analysis of variance was significant for almost all the traits under study. Combining ability analysis revealed constantly higher magnitude of SCA variance compared to GCA variance suggesting the preponderance of non additive gene action. Based on mean performance and gca effects Mattatriveni, Kanchana, Jyothi, Gouri ,Swarnaprabha, Mahsuri and Ponmani were identified as best parents which can be utilized in the crossing programme for the development of rice varieties having high yield potential. Among the hybrids Mattatriveni x Ponmani and Mattatriveni x Mahsuri were identified as superior cross combinations based on mean performance, sca effects and standard heterosis and they can be exploited in the creation of new plant type. Characters viz., panicle weight, panicle length, grains per panicle, plant height, 1000 grain weight, total dry matter, grain density and root length which showed significant positive correlation also recorded positive direct effect on grain yield revealing improvement of these characters can directly increase grain yield. Varieties which can be used as donor parents for these characters were identified. Since combination of desirable characters cannot be achieved through one generation of breeding further evaluation and back crossing with specific donor parents is suggested as future line of work.
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 and physiological analysis of ratooning in rice
(Department of Plant Breeding and Genetics, College of Horticulture, Vellanikkara, 2000) Ambili Nair, S; Rosamma, C A
The present investigation 'Genetic and physiological analysis of ratooning in rice (Oryza sativa L.)' was conducted at the Agricultural Research Station, Mannuthy during 1999-2000 to study the main crop as well as ratoon crop behaviour of different rice genotypes. The study was carried out to determine genetic variability among the different genotypes used. The study was also aimed at identifying morphological and physiological characters for a genotype of rice with high productivity when main and ratoon crop yields are combined together, through correlation and character association studies. Suitable selection indices were also formulated for identifying superior genotypes. Among the 50 genotypes evaluated in the main crop 24 showed regrowing ability. Of these five varieties viz. CO 43, IR 20, White Ponni, Ponmani and Mangala Mahsuri recorded better ratoon performance. The ratoon crop characters were less pronounced compared to the main crop characters except chlorophyll contents. But the above mentioned genotypes 'exhibited a higher intensity of character expression in both crops compared to the remaining genotypes. The estimates of GCV, heritability and genetic gain were high in the caseofratoon crop for most of the characters studied. Present study revealed that higher total yield can be achieved with a main crop having long duration and increased number of unproductive tillers plant". Ratoon yield can be improved by a better performing main crop with characters such as long duration, more number of grains panicle", more number of unproductive tillers plant" and reduced grain production day". Ratooning ability was considered as an index of the ratoon performance but in the present study ratooning ability recorded a negative direct effect on yield, indicating that this cannot be used as a true index to assess the ratoon performance. The various genetic and physiological analysis thus revealed that the varieties viz. IR 20, Mangala Mahsuri, White Ponni and Ponmani can be recommended as genotypes suitable for ratooning in Kerala. By using these about one third of the main crop yield can be achieved without increasing the land area. Total yield recorded 1;>y these genotypes were also significantly high.
Identification of stable male sterile lines and better combiners for exploitation of hybrid vigour in rice (Oryza Sativa L.)
(Department of Plant Breeding and Genetics, College of Horticulture, Vellanikkara, 1998) Rosamma, C A; Vijayakumar, N K
Investigations to identify stable male sterile lines and better combiners for the exploitation of hybrid vigour in rice were conducted at College of Horticulture, Vetlantkkara and at Agricultural Research Station, Mannuthy during 1994-98. The study included evaluation of cytoplasmic - genic male sterile (CMS) lines to identify stable lines, identification of maintainers and restorers for different CMS lines, inheritance of fertility restoration, studies on the genetic distance between maintainers and restorers and genetic analysis of the hybrids. Out of the ten CMS lines evaluated, seven were identified as stable for pollen and spikelet sterility behaviour. Studies on the floral traits which influence outcrossing expressed variation between CMS lines and between seasons. Jyothi, Aruna, Pavizham and Ptb 10 produced more number of sterile hybrids when crossed with CMS lines having WA cytoplasm and hence these varieties can be used as maintainers. More number of fertile hybrid combinations were produced by Annapoorna, Matta Triveni, Kanchana, IR 36 and Aiswarya indicating the use of these varieties as restorers for WA cytoplasmic source. All the genotypes under study produced sterile hybrids when crossed with CMS lines having O. perennis cytoplasm and no restorers could be identified for this new source of cytoplasmic male sterility. Inheritance studies on fertility restoration indicated polygenic mode of inheritance for this particular character. Forty four rice genotypes included in the hybrid rice breeding programme were grouped into nine clusters, each having different number of genotypes. Maintainers and restorers were distributed in different clusters and no direct relation could be established between heterosis and genetic distance of the parents. Genetic analysis of the 34 fertile hybrids resulted in the identification of five hybrids having significant positive standard heterosis. Among the male sterile lines IR 68890A was identified as the best combiner for most of the agronomic traits and IR 68890A/Aiswarya was the best specific hybrid combination. Magnitude of the gca variance was more than the variance due to sca for days to flowering, total duration, harvest index, 100 seed weight and other grain characters indicating predominance of additive variance for these characters. Variance due to sca was more for plant height, tillers per plant, total dry matter production, grain yield per plant, straw yield per plant, panicle length and filled grains per panicle indicating predornlnance of variance due to dominance and epistasis. Studies on association of characters in hybrids revealed that total drymatter accumulation, harvest index, number of filled grains per panicle, grain breadth, panicle weight, grain density, flag leaf area and leaf area index at 60 days after sowing were positively correlated with grain yield produced by the hybrids. Negative influence of sterile cytoplasm was identified for most of the agronomic attributes.
Inter-seasonal stability of high yielding rice genotypes
(Kerala Agricultural University, 1995) Elsy, C R; Rosamma, C A; Jose Mathew
Pigmented high yielding genotypes for wild rice infested wet lands
(Kerala Agricultural University, 1994) Rosamma, C A; Elsy, C R
PTB 47, a promising flood tolerant rice variety
(Kerala Agricultural University, 1993) Rosamma, C A; Karunakaran, K; Rajappan Nair, N
In order to identify a high yielding variety suited to the flood prone areas, a total of 405 entries were screened for their flood tolerance. Selected entries were yield tested for three seasons and finally BR 51-315-4, a semi-tall nonlodging variety with reasonably high grain as well as straw yield was identified as the ideal variety for these areas. Performance of this variety was highly promising in the multilocational farmers field trials also and this high yielding variety is capable of replacing all the traditional rice varieties in flood prone areas.
Red triveni, a promising rice variety
(Kerala Agricultural University, 1993) Rosamma, C A; Karunakaran, K; Rajappan Nair, N
Reselection has been effectively utilised as a breeding programme for defect elimination by many workers and a successful programme in this direction is discussed in this paper. Reselection was attempted in the variety Triveni in order to overcome the drawback of sprouting of grains on the panicle itself under high moisture conditions. While attempting for reselection, red riced plants which might have evolved through natural mutation were identified. Red riced plants wilh dormancy were selected after progeny testing and the new line was designated as Red Triveni. Red Triveni exhibited dormancy fora period of 15 to 20 days. Performance of this culture was highly promising in all the station trials and adaptive trials and was released as Ptb 45.
Stability of new rice genotypes for grain yield
(Kerala Agricultural University, 1994) Elsy, C R; Rosamma, C A; Prabhakaran, P V
The yield potential and grain yield stability of three medium duration rice cultures were studied over six cropping seasons at the Regional Agricultural Research Station, 1'attambi. Cul-8770 and Cul-8772 had shown stable high yield potential over the seasons. These two cultures recorded high mean yield and lesser deviation from regression. BR-51-46-1 with its lower mean yield and higher deviation from regression, is not suited for general cultivation, especi.illy during kharif season. The added advantage of Cul-8770 and Cul-8772 is the good straw yield and red bold grains which are highly preferred in Kerala. All these attributes make Cul-8770 and Cul-8772 suited for release as varieties for general cultivation.