Browsing by Author "Rajagopal, K."

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    Chlorophylls and nitrate reductase activity in relation to heterosis in coconut seedlings
    (1985) Shivashankar, S.; Rajagopal, K.; Ramadasan, A.
    The F1 progeny of Chowghat Dwarf Orange (CDO) and West Coast Tall (WCT) cross tend to be highly heterozygous with respect to the colour of petiole and seedling vigour. The study indicated that the greenish brown coloured vigorous plants had higher chlorophyll (a + b) content and nitrate reductase (NR) activity compared to the orange coloured vigorous plants and the dwarfs. The greenish brown seedlings were also characterized by a larger leaf area and shoot d. wt. The results provide biochemical evidence in support of the morphological criteria being used at present in the selection of hybrid coconut seedlings.
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    Genetic improvement of coconut palm - Combining ability of palms in Dwarf x Tall hybrids
    (2007-02) Satyabalan, K.; Rajagopal, K.
    Seedlings of eight combinations of Dwarf female x Tall male obtained from crosses between five Dwarf genotypes and three Tall genotypes were studied to identify the parental combination which would yield maximum number of hybrids. The palms were selected on the basis of nut characters like shell and copra content in the husked nuts of dwarf palms and husk and copra content in the fruits of tall palms. The seedlings obtained from these combinations were scored for heterotic hybrids on the basis of petiole colour and vigorous growth of the seedlings in the nursery. The study has indicated that to obtain maximum number of hybrid seedlings, it is preferable to select dwarf palms which yield nuts having a low shell content (less than 20 per cent of husked nut weight) as pistillate parents and tall palms which yield nuts which have less husk content (less than 50 per cent of the weight of fruit) and a high copra content per nut (above 150 gm per nut) as pollen parents. It may be possible to identify individual palms in both the parents which when combined may yield a large number of hybrid seedlings. Seedlings of the best combiners should be utilized for laying out hybrid seed gardens for large scale production of hybrids.
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    Genetic improvement of coconut palm- combining ability of palms in Dwarf x Tall hybrids
    (1987-06) Satyabalan, K.; Rajagopal, K.
    Seedlings of eight combinations of Dwarf female x Tall male obtained from crosses between five Dwarf genotypes and three Tall genotypes were studied to identify the parental combination which would yield maximum number of hybrids. The palms were selected on the basis of nut characters like shell and copra content in the husked nuts of dwarf palms and husk and copra content in the fruits of tall palms. The seedlings obtained from these combinations were scored for heterotic hybrids on the basis of petiole colour and vigorous growth of the seedlings in the nursery. The study has indicated that to obtain maximum number of hybrid seedlings, it is preferable to select dwarf palms which yield nuts having a low shell content (less than 20 per cent of husked nut weight) as pistillate parents and tall palms which yield nuts which have less husk content (less than SO per cent of the weight of fruit) and a high copra content per nut (above 150 gm per nut) as pollen parents. It may be possible to identify individual palms in both the parents which when combined may yield a large number of hybrid seedlings. Seedlings of the best combiners should be utilized for laying out hybrid seed gardens for large scale production of hybrids.
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    Genetic improvement of the coconut palm - Prepotency studies
    (2007-02) Satyabalan, K.; Rajagopal, K.
    A comparative study of two growth characters viz., collar girth and leaf production at the fifth month from germination of 1190 open pollinated progenies of 43 high yielding mother palms and 224 open pollinated progenies of 10 high yielding mother palms has indicated that the progenies of only five palms are superior to those of others in the nursery. In these palms 60% and above of their progenies have growth characters above the general mean of 1414 progenies of 53 palms. Three of these mother palms come under the first and third groups and are stable high yielders, yielding more than 80 nuts per palm per year and give a copra outturn of more than 15 kg per palm per year. The fourth one belongs to the second group, the copra outturn of which is low, and hence not considered. The fifth one belongs to the second lot of the fifth group of stable high yielders. The growth of the progenies of the selected four palms at the fifth month from the time of germination is in general more vigorous irrespective of the months of harvest and germination when compared to others. These palms which show a high rate of transmission of growth characters to their progenies can be considered as likely prepotents. In another study, of 146 F2 open pollinated progenies derived from three high yielding prepotent palms indicated that prepotency is not transmitted to all the open pollinated second generation progenies.
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    Genetic improvement of the coconut palm- prepotency studies
    (1985-12) Satyabalan, K.; Rajagopal, K.
    A comparative study of two growth characters viz., collar girth and leaf production at the fifth month from germination of 1190 open pollinated progenies of 43 high yielding mother palms and 224 open pollinated progenies of 10 high yielding mother palms has indicated that the progenies of only five palms are superior to those of others in the nursery. In these palms 60% and above of their progenies have growth characters above the general mean of 1414 progenies of S3 palms. Three of theae mother palms come under the first and third groups and are stable high yielders, yielding more than 80 nuts per palm per year and give a copra outturn of more than 15 kg per palm per year. The fourth one belongs to the second group, the copra outturn of which is low, and hence not considered. The fifth one belongs to the second lot of the fifth group of stable high yielders. The growth of the progenies of the selected four palms at the fifth month from the time of germination is in general more vigorous irrespective of the months of harvest and germination when compared to others. These palms which show a high rate of transmission of growlh characters to their progenies can be considered as likely prepotents. In another study, of 146 F2 open pollinated progenies derived from three high yielding prepotent palms indicated that prepotency is not transmitted to all the open pollinated second generation progenies.