TITLE	Metabolic changes during rooting in pre-girdled stem cuttings and air-layers of Heritiera
AUTHOR	P. Das Mangrove Research Centre, Regional Plant Resource Centre, Bhubaneswar 751 015, Orissa, India U.C. Basak Mangrove Research Centre, Regional Plant Resource Centre, Bhubaneswar 751 015, Orissa, India A.B. Das Mangrove Research Centre, Regional Plant Resource Centre, Bhubaneswar 751 015, Orissa, India
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ABSTRACT	The mangroves of the Mahanadi Delta are unique and include 62 of the 64 mangrove species distributed in India. Vegetative propagation through rooting in stem cuttings and air-layers of Heritiera fomes and H. littoralis, commonly known as Sundri, using IAA, IBA, and NAA is reported. Significant increase in the root number was recorded in the air-layers and the pre-girdled stem cuttings of H. fomes treated together with IBA (5,000 ppm) and NAA (2,500 ppm) as compared to H. littoralis. The maximum number of roots was obtained in H. littoralis with IBA (5,000 ppm) and NAA (1,000 ppm). The overall rooting response was better in the treatments with IBA and NAA rather than with IAA and NAA combinations. Variation in the rooting response due to the exogenous application of auxins was also reflected in the metabolic changes during the initiation, emergence, and development of roots in the cuttings and the air-layers. An increase in the level of reducing sugars was noted in the pre-girdled tissues at initiation as well as at subsequent stages of root development, which was further enhanced by the use of auxins. A decrease in the total sugar, carbohydrate, and polyphenols and an increase in the total nitrogen and a high C/N ratio were noted at the root initiation stage in both species. There was less accumulation of photosynthates and nitrogen in the above-girdled tissues in air-layers than the pre-girdled cuttings. Interaction of IBA and NAA promoted starch hydrolysis during root development and subsequently reduced the C/N ratio and increased the protein-nitrogen activity during the development of root primordia. The auxin influenced mobilization of nitrogen to the rooting zone promoted the rooting efficiency in Heritiera.
KEYWORD	Auxins; C/N ratio; Heritiera; Mangroves; Rooting; Sugars;
ARTICLE INFO	Botanical Bulletin of Academia Sinica, Volume 38 Number 2 April 1997, page 91-95, 5 pages
PUBLISHER	Institute of Plant and Microbial Biology, Academia Sinica, Taipei, Taiwan, Republic of China