|
|
黑暗条件下逆境胁迫诱导油菜籽次生休眠
收藏
周伟军 KRISTIANSSON Bo
浙江大学学报(农业与生命科学版). 2000 (5): 477-478.
Oilseed rape seeds (Brassica napus L.) harvested from mature plants require only imbibition of water and a suitable temperature. Despite this absence of primary dormancy, there is evidence that rapeseeds, due to the induction of secondary dormancy, are able to persist in the field for up to 10 years, and thus can emerge as volunteer plants in later crops. In addition, volunteers originate from seeds shed before and during harvest. The level of seed losses is influenced by the timing and technique of harvest, and can reach several thousand seeds per m2. As a consequence of both these effects, problems from volunteer rape occur frequently in subsequent crops. Volunteer rape has been particularly troublesome in broad-leaved crops. It is a highly competitive weed and due to its prolonged period of emergence, timing of herbicide application is sometimes a problem. Volunteer rape can contaminate the sown crop resulting in heterogenous mixtures of seeds. This not only affects breeding and the production of seed crops, but can also affect growers when they switch from one type or quality of rape to another, or if they grow different rape qualities in one rotation, e.g., rapeseed for human consumption in the normal rotation and rapeseed for industrial use on set-aside land. The problem will not disappear with the introduction of herbicide resistant oilseed rape, as there are no indications that seeds of these cultivars will not have the potential to persist. The ability of rapeseed to persist in the soil for a long time and at high percentages also has to be taken into account in risk assessment of genetically manipulated rape, as rape can escape in space by pollen transfer or in time via the soil seedbank. Although hybridization between oilseed rape and wild crucifers is infrequent, it does occur. Traits, such as herbicide resistance or pest and disease resistance, if transferred into wild plants have the potential to alter the agro-ecosystem significantly.……
|
|
|
瓠瓜果实发育中的蛋白质SDS-PAGE分析
收藏
李英 喻景权 朱祝军
浙江大学学报(农业与生命科学版). 2000 (5): 579-580.
In seed plants, successful fruit set and subsequent development are dependent on pollination and fertilization since fertilization activates cell division and triggers fruit development by producing phytohormones especially auxins and GAs. Fruit set was very low in Lagenaria leucantha Rusby during early spring. We found that CPPU ［N-(chloro-4-pyridyl)-N′-phenyurea］, a new kind of cytokinin, was more effective than NAA and GA3 in inducing parthenocarpic fruit growth and in decreasing fruit abortion. In this paper, we examined the possible role of fertilization and CPPU in protein synthesis in developing fruit of Lagenaria leucantha by SDS-PAGE analysis. 1 Materials and Methods 1.1 Plant materials Seeds of Lagenaria leucantha Rusby (cv. Hangzhou long- gourd) were sown on 15 February 1999, and the seedlings were transplanted on 20 March. There were three treatments: Nonpollination; Hand pollination, and Nonpollination+50 mg/L CPPU. Unpollinated ovaries were prepared by bagging the female flowers one day before anthesis. The solution of CPPU was applied with a spray to ovaries of bagged female flowers at anthesis at the rate of 0.5 mL per ovary. Fruit length was recorded every three days. For assays of protein, the flesh of fruits at anthesis and 8 days after treatment was frozen in liquid nitrogen and stored at -20 ℃. 1.2 Extraction of proteins Half gram of fruit tissue was homogenized in 1 mL extract buffer containing 25 mmol/L DTT and 250 mmol/L Tris-HCl, pH6.8. The homogenate was centrifuged at 12 500 g for 20 min. Aliquot of the 250 μL supernatant was added into an eppendorf tube filled with 1 mL of 80% acetone, then frozen in -20 ℃ for 10 min. After thawing at 25 ℃, it was centrifuged at 10 000 g for 10 min, the supernatant was carefully discarded.……
|
|
