Determination of resource mobilization during seedling growth of palmyra palm, Borassus flabellifer L.

498-509Asian palmyra palm (Borassus flabellifer L.) is a multipurpose tree with year round products as food for the dependent society. Besides edible items the tree offers around 801 useful goods which are economically important. Such a plant’s seedling bilogy has not been fully understood. Hence, the present study was aimed at understanding seedling developmental stages and resource mobilisation in Palmyra palm and further to determine the role of cotyledonary sheath (CS) during entire seedling growth. We investigated the developmental changes throughout growth of seedlings by providing different sets of growth conditions. Artificial seed bed made of coconut coir was compared with that of soil conditions to study germination and establishment of seedlings. Phloem loading dye was used to track the flow of nutrients from embryo to cotyledonary sheath. Seed germination in palmyra palm is hypogeal by forming ligular and tubular structures remotely in soil. Eight new organs differentiate from the seed embryo that includes haustorium, ligule, cotyledonary sheath, cataphyll, eophyll, mesocotyle (junction), primary root and mesocotyl roots during seed germination. Among these the first four are temporary organs and they disentegrate once the seedling is well established. The last four organs are responsible for developing a complete plantlet at later stages. The seed and seedling organs of Palmyra palm have four major storage reserves to support successful germination and firm establishment of seedling. Palmyra has evolved to control the solubilisation, movement and regulation of food among transient seedling organs and carry out translocation of food to the developing and differentiating organs. Seedlings also have developed physiological functions and strategies to mobilise the stored food without losing them at any point of their growth and developmental stages. Water required for seed germination permeates laterally only via cotyledonary sheath which has spongy tissues and lenticels all over. These tissues are the primary mode of water supply as the seedlings lack major root organs in the early stages of development. Flourescent microscopic and anatomical studies were carried out to observe the transport and storage of food substances required during seedling growth. Histochemical studies of seedling organs have revealed the presence of various type of nutrients such as simple sugars, carbohydrates, proteins, amino acids and lipids

Determination of resource mobilization during seedling growth ofpalmyra palm, Borassus flabellifer L.

Asian palmyra palm (Borassus flabellifer L.) is a multipurpose tree with year round products as food for the dependentsociety. Besides edible items the tree offers around 801 useful goods which are economically important. Such a plant’sseedling bilogy has not been fully understood. Hence, the present study was aimed at understanding seedling developmentalstages and resource mobilisation in Palmyra palm and further to determine the role of cotyledonary sheath (CS) during entireseedling growth. We investigated the developmental changes throughout growth of seedlings by providing different sets ofgrowth conditions. Artificial seed bed made of coconut coir was compared with that of soil conditions to study germinationand establishment of seedlings. Phloem loading dye was used to track the flow of nutrients from embryo to cotyledonarysheath. Seed germination in palmyra palm is hypogeal by forming ligular and tubular structures remotely in soil. Eight neworgans differentiate from the seed embryo that includes haustorium, ligule, cotyledonary sheath, cataphyll, eophyll,mesocotyle (junction), primary root and mesocotyl roots during seed germination. Among these the first four are temporaryorgans and they disentegrate once the seedling is well established. The last four organs are responsible for developing acomplete plantlet at later stages. The seed and seedling organs of Palmyra palm have four major storage reserves to supportsuccessful germination and firm establishment of seedling. Palmyra has evolved to control the solubilisation, movement andregulation of food among transient seedling organs and carry out translocation of food to the developing and differentiatingorgans. Seedlings also have developed physiological functions and strategies to mobilise the stored food without losing themat any point of their growth and developmental stages. Water required for seed germination permeates laterally only viacotyledonary sheath which has spongy tissues and lenticels all over. These tissues are the primary mode of water supply asthe seedlings lack major root organs in the early stages of development. Flourescent microscopic and anatomical studieswere carried out to observe the transport and storage of food substances required during seedling growth. Histochemicalstudies of seedling organs have revealed the presence of various type of nutrients such as simple sugars, carbohydrates,proteins, amino acids and lipids

Superconductivity on a crossover phenomenon of spin–ladder system SrCa13Cu24O41 single crystals

Electrical resistivity and alternating current susceptibility measurements were performed for the spin–ladder compound SrCa13Cu24O41 under hydrostatic pressure up to 8 GPa. The superconducting transition was observed below TC = 14.7 K at pressures above 2 GPa. By using high-quality single crystals, the bulk superconductivity with a volume fraction of 50% and temperature quadratic behavior of the normal state resistivity were observed above 3.7 GPa. They suggest that a strong interladder interaction induces the bulk superconductivity and transforms the system into a Fermi-liquid-like state. The optimal pressure was in a crossover region and the highest TC was observed without going through the bulk superconducting state. Our results suggest that the superconducting state on the crossover phenomenon presents the feature of the doped two-leg spin–ladder system because the spin gap was observed in this compound. © 2014, The Physical Society of Japan