Browsing by Author "Vijayakumar, G."

Now showing 1 - 9 of 9
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    Comparative performance of progenies from Chowghat Dwarf Orange coconut
    (2007-02-08) Satyabalan, K.; Vijayakumar, G.
    A comparative study was made of yield attributes and nut characters of the progenies of Chowghat Dwarf Orange, selected for seedling vigour from four different populations obtained by four different methods, viz. (1) unemasculated and open-pollinated, (2) unemasculated and selfed, (3) emasculated and hybridized with WCT, (4) emasculated and open-pollinated. Data indicate that progenies from population (3) gave the highest cumulative yield as well as annual yield, closely followed by those from population (2) although this relationship was not maintained for the other yield attributes studied. The mean copra outturn as well as oil content was maximum in progenies from population (2) followed by those from (3).
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    Cytological behaviour of first inbred generation of coconut
    (2007-02-08) Nambiar, M.C.; Thankamma Pillai, P.K.; Vijayakumar, G.
    Cytological consequences of inbreeding in a few geographically distinct exotic varieties of coconut palms available at Central Coconut Research Station, Kasaragod, were studied Inbred and open-pollinated progenies of Laccadive, Andaman, Philippine, New Guinea and Cochin China varieties and green, -yellow and orange types of dwarf variety of indigenous and Malayan origin -were screened for their meiotic behaviour. Meiosis was comparatively more regular in both inbred and open-pollinated progenies of Laccadive variety. Inbred progenies of Philippines and Andaman varieties and both inbred and open pollinated progenies of Cochin China and New Guinea show com paratively higher frequency of chromosome aberrations and higher percentage of pollen sterility. It is suggested that inbreeding depression observed inPhilippine, Andaman and Cochin China varieties and lack of inbreeding depression in Laccadive varieties is either due to the difference in the intensity of inbreeding and selection between these geographically distinct varieties or to the Laccadive genotypes being comparatively less sensitive to inbreeding.
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    Cytology of an abnormal coconut palm
    (2007-02-08) Thankamma Pillai, P.K.; Vijayakumar, G.
    Studies on the course of microscoporogenesis in the progeny of a self-polljinated New Guinea palm revealed highly aberrant meiosis. The sterility in this palm has been attributed to inbreeding.
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    Cytology of coconut
    (2007-02-08) Thankamma Pillai, P.K.; Vijayakumar, G.; Ravindran, P.N.
    The chromosome number in coconut is 2n=32. Karyomorphological studies show light differences between Tall and Dwarf varieties. Meiosis was generally regular ,n Tall cultivars and in hybrids between Tall and Dwarf, while several irregularities have been reported in the Dwarf and semi-tall cultivars. Pollen fertility is very high in Tails and hybrids as compared to that in Dwarfs and semi-tails. Meiotic irregularities are commonly met within the spicata palms and these are believed to have originated from Tails. Free nuclear division has been reported in coconut milk. C-mitosis leading to high ploidy level and several chromosome abnormalities occur in developing endosperm. In Philippines makapuno nuts, the endosperm development is very abnormal. An inverse relationship between ploidy level and oil content has been also observed by some authors. The two existing views on the origin of Dwarfs from Tails, namely, mutant origin or by continuous inbreeding, are presented. Another possibility that both Tails and Dwarfs might have had a common origin in a single ancestral form has been proposed.
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    Floral Biology - Study of pollination and fertilisation
    (Central Plantation Crops Research Institute Kasaragod - 671 124,Kerala, 1976-12) Vijayakumar, G.
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    Flowering behaviour, cytology, and pollen germination in ginger (Zingiber officinale Rosc.)
    (2007-02) Thankamma Pillai, P.K.; Vijayakumar, G.; Nambiar, M.C.
    The flowers of Zingiber officinale are trimerous, with an attractive labellum, a single fertile stamen, and an inferior ovary with many ovules on an axile placentum. The ovule is -anatropus and bitegmic. Meiosis was highly irregular. Only 37 % of the pollen grains was stainable in aceto-carmine. Maximum germination observed in an artificial medium was only 14.5 %.
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    Path Coefficient Analysis in Coconut
    (2007-02) Sukumaran, C.K.; Narasimhayya, C.; Vijayakumar, G.
    Yield in coconut is a complex character dependent upon a large number of components and their interactions. Path coefficient analysis was carried out to know direct and indirect effects of characters influencing yield. The correlation coefficients were partitioned into direct effects (path coefficients) and indirect effects in order to pinpoint the direct and indirect effects of these associations. In 43 progenies of eight high yielding W.C.T. palms of known parentage, planted at CPCRI, Kasaragod in 1953, 12 vegetative as well as reproductive characters observable at different stages of growth till yield stabilization were observed. The age of plants was calculated from the date of sowing of nuts. Path coefficient analysis was carried out for two yield characters namely, (1) yield of nuts during stabilized period, (2) cumulative yield upto 24 years after sowing, taking two sets of yield contributing characters. Seven yield contributing characters were kept common in these two analyses. The analysis for yield of nuts during stabilized period showed that the major contributing characters which influenced directly or indirectly were average number of female flowers, number of functioning leaves at 19 years, and internodal distance at fixed mark. These characters influenced yield negatively indicating their value in selection.
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    Yield and Nut Characteristics of Open—Pollinated Progeny of West Coast Tall and its Hybrids with Chowghat Dwarf Orange and Gangabondam
    (1984) Vijayakumar, G.; Satyabalan, K.
    A comparative study was made of the performance of open-pollinated progency of West Coast Tall (WCT), and its hybrids with Chowghat Dwarf Orange (CDO) and Gangabondam (GB) planted in laterite soil and maintained under rainfed conditions with the usual recommended dose of fertilisers. The superiority of the hybrids over WCT, and among the hybrids, the superiority of CDOxWCT over the reciprocal hybrids WCT x CDO and WCTxGB m yield of nuts, copra and oil out-turn was observed. The study has also shown that CDOxWCT hybrids wilt he more suitable and will have to be preferred to the order two hybrids and the local WCT to increase coconut production under the laterite soil conditions in the country.
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    Yield and Nut Characteristics of Open—Pollinated Progeny of West Coast Tall and its Hybrids with Chowghat Dwarf Orange and Gangabondam
    (1982) Vijayakumar, G.; Satyabalan, K.
    A comparative study was made of the performance of open-pollinated progency of West Coast Tall (WCT), and its hybrids with Chowghat Dwarf Orange (CDO) and Gangabondam (GB) planted in laterite soil and maintained under rainfed conditions with the usual recommended dose of fertilizers. The superiority of the hybrids over WCT, and among the hybrids, the superiority of CDOxWCT over the reciprocal hybrids WCT x CDO and WCTxGB in yield of nuts, copra and oil out-turn was observed. The study has also shown that CDOxWCT hybrids will be more suitable and will have to be preferred to the other two hybrids and the local WCT to increase coconut production under the laterite soil conditions in the country.