Germination response of black and yellow seed coated canola (Brassica napus) lines to chemical treatments under cold temperature conditions

Abstract

Seed quality is a key critical component to produce well established and vigorous seedlings under cool soil (\10°C) conditions experienced in Western Canada. A simple, relatively quick germination assay is required to separate small differences in seed germination which can have a significant impact on seedling growth. It has long been established that phytohormones regulate seed germination: abscisic acid inhibits germination whereas gibberellins enhance germination. We investigated the effects of ABA, GA, ethylene and inhibitors of these phytohormones alone and in combination on the germination rate of a black and a yellow seed canola (Brassica napus) imbibed at 8°C. The effects of either saline solutions, osmotic solutions, fusicoccin or testa on the germination of canola seeds imbibed at 8°C were also investigated. This temperature is representative of the soil temperatures experienced in the early spring of Western Canada. The two canola seed lines, especially the yellow seed line, were very sensitive to increasing concentration of saline solutions at 8°C, but not at 23°C; however, iso-osmotic solutions that reduced water potential were more inhibitory. The seed coat (testa) including the endosperm was a major factor affecting the germination rate of the yellow seed line at 8°C, however, GA 4?7 overcame the inhibitory effect of the testa, whereas ABA exacerbated it. Fusicoccin was more stimulatory to germination than GA 4?7 , however, unlike GA 4?7 , it was unable to overcome the inhibitory effect of paclobutrazol, a GA biosynthesis inhibitor. Fluridone, an ABA biosynthesis inhibitor, was unable to overcome the inhibitory effects of a saline solution suggesting that the inhibitory effect was not due to elevated ABA levels. Ethylene, a stimulator of germination did not appear to be involved in the germination of these two lines. Controlled deterioration at 35°C, 85% RH could be either partially or completely overcome by exogenous GA 4?7 . This study demonstrated the effect of hormones, salinity and testa on the germination of canola seeds under less than ideal environmental conditions.

Chlorophyll Fluorescence Sorting Method to Improve Quality of Capsicum Pepper Seed Lots Produced from Different Maturity Fruits

“…This may be alleviated by better seed production practices, i.e., harvesting at maximum maturity, which would reduce the proportion of lowquality seed. Moreover, use of the technique may be limited in cases in which seedcoat chlorophyll content or color may vary dramatically among cultivars within the same species, like in Brassica napus (Zhang and Gusta, 2010). In our work, CF worked on the four cultivars examined, and this shows that the method may be well suited for Capsicum annuum.…”

Patterns of amplified restriction fragment polymorphism in the germination ofFestuca halliiseeds

“…Second, seed germination potential is genetically controlled in dry seeds, while the germination rate is controlled by changes of gene expression initiated upon imbibition (Rajjou et al , 2004; Holdsworth et al , 2008). Zhang (2008) found differences in gene expression pattern between 50% germinated and 50% ungerminated canola seeds imbibed in water, gibberellic acid (GA), saline and abscisic acid (ABA) solutions. These differences may be due to genetic sorting during imbibition in different solutions.…”