CYTOPLASMIC LABEL FOLLOWING TRITIATED THYMIDINE TREATMENT OF ALLIUM CEPA L. ROOTS

Cytoplasmic Label following Tritiated Thymidine Treatment of Allium Cepa L. Roots

Tritiated thymidine routinely labels onion root cytoplasm during most of the cell cycle. One-third of this label could be cytochemically identified as DNA. The balance of the label was not RNA or a lipid, or attributable to labeled impurities in thymidine-(3)H. In electron microscope radioautographs one-third of the cytoplasmic silver grains was over organelles, presumably mitochondria and plas...

Assessment report on Allium cepa L., bulbus

Frequencies of plasmodesmata in Allium cepa L. roots: implications for solute transport pathways.

Plasmodesmatal frequencies (PFs) were analysed in Allium cepa L. roots with a mature exodermis (100 mm from the tip). For all interfaces within the root, the numbers of plasmodesmata (PD) microm(-2) wall surface (Fw) were calculated from measurements of 60 walls on ultrathin sections. For tissues ranging from the epidermis up to the stelar parenchyma, the frequencies were also expressed as tota...

Cytological Effects of 5- Amino Uracil on Allium cepa L. roots

5Amino Uracil is a structural analogue of pyrimidine. In this work the cytological effects of 5-AU has been evaluated in the root tip cells of Allium cepa L. following treatment with different concentrations for different durations. Microscopical observation of the cells revealed that 5-AU has considerable clastogenic activities as evidenced by altered MI (Mitotic index) values as well as occur...

Effect of sulphur application in onion (Allium cepa L.)

An experiment was conducted to study the effect of sulphur application on growth, yield and quality of onion at Horticulture Farm of Institute of Agriculture, Visva-Bharati, Sriniketan. The treatments consisted of six incremental doses of sulphur application (10, 20, 30, 40, 50 and 60 kg ha-1) and no sulphur application (control, 0 kg S ha-1). Treatments were arranged in Randomized Block Design...