Seed Germination in Chenopodium album L

Abstract

feasibility of using ethylene or nitrate to enhance seed germination in the field.The initial experiments reported here were done to assess whether a combination of ethylene and nitrate could induce uniformly high germination in this seed. These investigations led to the information on the influence of the endogenous and exogenous availability of nitrate on the response of seeds to hormonal treatments. MATERIALS AND METHODSChenopodium album L. seeds were collected in the fall of 1982 and 1983 from the University of Alberta Parkland Farm and kept in dry storage in airtight glass bottles at -24°C. These storage conditions did not affect the degree of dormancy over the period of experimentation.Ethylene was administered either as ethephon (2-chloroethylphosphonic acid; Union Carbide) or in the gaseous form. Seeds were exposed to gaseous ethylene by placing open Petri plates inside flow-through plexiglass chambers, connected to a continuous flow of humidified air containing known amounts of ethylene. Potassium nitrate and GA4+7 were dissolved in distilled H20. Kinetin was dissolved in 1 N HCI and diluted with distilled H20 to the HCI concentration of 0.001 N. In experiments with kinetin as a treatment, the concentration of HCI in solutions of other chemicals was also was made to 0.001 N and the pH of each solution was adjusted to 6.0 with 1% (w/v) NaOH.Seeds were imbibed in 10-cm Petri plates, each containing one layer of Whatman No. 3 filter paper and 7 ml of the relevant solution or distilled H20. Each plate contained 100 to 150 seeds in all experiments, except that the interaction between GA4+7 and nitrate was studied using 50 seeds per plate. Plates were sealed with parafilm to minimize moisture loss, and were incubated in the dark at temperatures ranging from 12 to 32 ± 0. 1°C.The seeds were considered germinated when the protrusion of the radicle was visible with the naked eye. The extent of germination was recorded after 10 d of incubation. In the experiments where the rate of germination was studied, germination counts were taken from independent sets of plates on each day. This was done to eliminate any possible effect of seed movement during counting on germination.

Nitric oxide implication in the control of seed dormancy and germination

“…Thus, nitrate could stimulate the accumulation of cGMP, which then promotes some phytochrome responses (Ludidi and Gehring, 2003). Moreover, a positive correlation between endogenous or applied nitrate levels and germination response to ethylene or GAs was reported for Chenopodium album seeds (Saini et al, 1985). In Arabidopsis , high nitrate feeding of mother plants is associated with higher nitrate content and lower dormancy of the seed progeny (Alboresi et al, 2005).…”

Physiological quality of osmoprimed eggplant seeds

“…Trigo, Nedel and Trigo (1999) comment that the advantage of priming with KNO 3 may be related to the fact that this may act as an additional source of potassium and nitrogen during seed germination. Other researchers claim that the nitrate combined with some environmental factors, like temperature and light, may stimulate the synthesis of gibberellins and promote germination (SAINI; BASSI; SPENCER, 1985;HILHORST;SMITT;KARSSEN, 1986 Table 3 -Comparison between the control and each treatment from the factorial to the percentage of germination (PG), percentage of emergence (PE), speed index of emergence (SIE) and electric conductivity (EC -µS cm -1 g -1 ).…”

TheArabidopsisATNRT2.7 Nitrate Transporter Controls Nitrate Content in Seeds

“…In Sisymbrium officinale, seed nitrate was shown to be a necessary and limiting factor for light-induced germination in water (Hilhorst, 1990) and to be present both in seed coats (including the endosperm) and in the embryo, particularly in the axes and the radicle. The important role of nitrate alone or in combination with other factors, such as light, gibberellins, or ethylene, in breaking dormancy has also been shown in different species (Saini et al, 1985;Hilhorst and Karssen, 1988). It was recently demonstrated that the effect of nitrate in breaking dormancy in Arabidopsis is not nutritional but rather a signaling effect, whether it is provided exogenously during imbibition or accumulated during seed development (Alboresi et al, 2005).…”