Shoot

About: Shoot is a research topic. Over the lifetime, 32188 publications have been published within this topic receiving 693348 citations.

Micropropagation of Phalaenopsis and Doritaenopsis by culturing shoot tips of flower stalk buds.

Abstract: Green Protocorm-like Bodies (PLB) with high multiplication capacity were induced from shoot tips of flower stalk buds having 1 or 2 leaf primordia using New Dogashima Medium (NDM) containing 0.1 mg l−1 α-naphthaleneacetic acid (NAA) and 1 mg 1−1 6-benzylaminopurine (BAP). These PLB were subcultured on the same medium. More than 10,000 PLBs were obtained from a few buds on a single flower stalk within one year. After transfer onto NDM containing no plant growth regulator (PGR), the PLB developed into plantlets. The micropropagation method formulated in this study was applicable to 12 different genotypes. These results suggest that the methodology could be used on a commercial scale for vegetative propagation of Phalaenopsis and Doritaenopsis.

Arbuscular mycorrhizal fungi native from a Mediterranean saline area enhance maize tolerance to salinity through improved ion homeostasis

Abstract: Soil salinity restricts plant growth and productivity. Na + rep- resents the major ion causing toxicity because it competes with K + for binding sites at the plasma membrane. Inocula- tion with arbuscular mycorrhizal fungi (AMF) can alleviate salt stress in the host plant through several mechanisms. These may include ion selection during the fungal uptake of nutrients from the soil or during transfer to the host plant. AM benefits could be enhanced when native AMF isolates are used.Thus, we investigated whether native AMF isolated from an area with problems of salinity and desertification can help maize plants to overcome the negative effects of salinity stress better than non-AM plants or plants inoculated with non-native AMF. Results showed that plants inoculated with two out the three native AMF had the highest shoot dry biomass at all salinity levels. Plants inoculated with the three native AMF showed significant increase of K + and reduced Na + accumulation as compared to non-mycorrhizal plants, concomitantly with higher K + /Na + ratios in their tissues. For the first time, these effects have been correlated with regula- tion of ZmAKT2, ZmSOS1 and ZmSKOR genes expression in the roots of maize, contributing to K + and Na + homeostasis

The effect of developmental stage on direction of translocation of photosynthate in Vitis vinifera

Abstract: The direction of translocation of C14 following the assimilation of C14O2 by single leaves or shoot tips of the Muscat of Alexandria grapevine was determined by using radioautographic techniques. The first assimilate exported by the treated leaf was to the shoot tip. When the treated leaf was separated from the oldest importing leaf on the shoot tip by two or three other exporting leaves, the assimilate from the leaf was translocated both to the shoot tip and to the parent vine. With further shoot growth the basipetal movement predominated until translocation from a treated leaf below the shoot tip was completely reversed and was basipetal only. Translocation from leaves below the cluster was partially reversed again when fruit development started. Assimilate from these leaves was translocated both to the fruit cluster and parent vine. After the rate of shoot elongation decreased sharply, radiocarbon moved from the shoot tip in a basipetal direction. The young inflorescence had small power as a sink compared to the shoot tip and the parent vine, and was unable to influence the direction of translocation. From 10 to 14 days before bioom until fruit set the cluster was a weak sink. Axillary buds, tendrils, xylem, parenchyma, and pith were found normally to be weak sinks relative to the developing fruit cluster and unable to influence the longitudinal direction of translocation. Axillary shoots behaved as young leaves until 1 or 2 of their leaves were mature. Then no assimilate moved into them from the main shoot. Shoot tips and parent vines were more powerful sinks than the cluster during flower development but not during fruit set. Girdling and topping thus affect fruit set because they divert more assimilates into the cluster just prior to fruit set.

Growth, physiological and anatomical responses of two wheat genotypes to waterlogging and nutrient supply

Abstract: In order to investigate the responses of plant genotypes to waterlogging and nutrient supply, physiological, morphological, and anatomical features were determined for two genotypes of winter wheat (Triticum aestivum), «Bayles» and «Savannah». Plants were grown in a growth chamber and fertilized with half-strength or full-strength Hoagland's solution during 17 d of waterlogging. Waterlogging reduced leaf water potential, stomatal conductance, photosynthesis, chlorophyll content, shoot nitrogen content, shoot and root growth for both Bayles and Savannah; however, there were more adverse effects on Bayles than on Savannah