Leading up to the National Moth Week on July 22, we interview some contributors of moth observations.Listen to the first podcast episode with Nagesh O. S. on the IBP blog.

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2 documents found tagged stigma receptivity [X]
  • Title
    Evaluation of some mangrove species on the nature of their reproduction along the coastal belt of the Indian Sunderbans
    Type
    Journal Article
    Description
    Reproductive biology of three dominating mangrove species Rhizophora mucronata, Ceriops decandra and Avicennia marina from the Indian Sunderbans were studied. A comparative account on all floral parts revealed that as the bud progresses to completely open, the length of androecium surpassed the length of gynoecium and the anther matured first thus showing protandrous nature and favouring cross-fertilization. A study of pollen grain viability revealed that all of them produces fairly good amounts of viable pollen grains in their natural condition. The pollens showed their maximum viability late in the morning till early noon. The stigma showed peak receptivity after three days of flower opening in C. decandra and four days of flower opening in R. mucronata and A. marina. All the species showed out-breeding mechanism of pollination. The fruit setting percentage obtained by xenogamy was the highest and autogamy failed to show any result in all the three genera. Although Ceriops decandra and Avicennia marina showed very limited fruit set with geitonogamy, these two species can be called facultative out-crossers, while Rhizophora was obligate outcrosser in nature. The study on floral structure, pollen viability along with stigma receptivity of the investigated taxa guided to maximum exploitation of reproductive behavior for rising artificial and natural plant population in addition to build up a future research strategy in ecosystem conservation.
    Attribution
    Ghosh Arunima, Chakraborti Prabir (2012). Journal of Threatened Taxa 3(4) pp. 2427-2435; doi:10.11609/JoTT.o2416.2427-35
  • Title
    Pollination biology of Impatiens cuspidate Wight and Arn. (Balsaminaceae), a rare and endemic balsam of the Western Ghats, India
    Type
    Journal Article
    Description
    The pollination biology of Impatiens cuspidata, a rare and endemic balsam from the Western Ghats, has been studied with special reference to phenology, pollination, pollen-pistil interactions, breeding experiments and stigma receptivity. It flowers at night between 2330 and 0430 hr; flowering days extend up to 160 days in a year. The anther dehisced one day before anthesis, which confirmed the protandrous condition of the flower. Pollen-ovule ratio was calculated as 1729:1. Hawk moths, honeybees, flies and butterflies are the major pollinators of Impatiens cuspidata. Pollen grains are oval, having an average diameter of 28.24μm. Pollen viability by FCR test confirmed that 82% pollen grains are viable on the day of anthesis. Best pollen germination along with 1636μm tube development was achieved in Brewbakers medium. Stigma was more receptive (up to 80%) on the first day of flower opening. It chiefly reproduced by means of cross pollination, where the fruit set was only 40%, but artificial cross-pollination through xenogamy enhanced fruit set up to 80%. The plant is an obligate out-crosser and self incompatible, as confirmed by various hand pollination experiments. Seed germination in natural and controlled conditions was only 20%. Its dependence on a specialized habitat, bottlenecks in sexual reproduction, low percentage of seed germination and other abiotic factors could be reasons for its limited distribution and endemism.
    Attribution
    Sreekala A.K., Pandurangan A.G., Ramasubbu R., Kulloli S.K. (2011). Journal of Threatened Taxa 6(3) pp. 1818-1825; doi:10.11609/JoTT.o2385.1818-25