Studies On Pre-Harvest Sprouting Resistance In Brassica Napus

A series of studies on pre-harvest sprouting resistance in Brassica napus is conducted in this paper, including seed germination, effects of seed germination on its yield and quality, investigation of hormones in fresh shells and seeds, Water absorbing rate and its correlation with pre-harvest sprouting percentage, effects of different concentrations of Abscisin acid(ABA) and Gibberellin-3-acid(GA3) on seed germination. The main results are as follows:1. Percentages of pre-harvest sprouting in crop field and laboratory, germination of seeds newly harvested are investigated. The results show that different percentage of pre-harvest sprouting were found among different varieties of Brassica napus, the shell is the key factor in pre-harvest sprouting.2. The pre-harvest sprouting effects of 780,890 and 11-5 on their yields and qualities are analyzed. The results show that 1000 seeds weights decline by 5.52-22.17%; oil and erucic acid contents decline too; but contents of glucosinolate and protein increase.3. High performance liquid chromatographic (HPLC) determination of internal hormones including abscisic acid (ABA), Indole acetic acid(IAA), Cytokinin(CK) in fresh shell and seed. The results suggest that pre-harvest sprouting of Brassica napus belongs to outer inhibition mechanism caused mainly by abscisic acid.4. The experiment is conducted to study siliqua water absorbing rate and its relation with seed germination in Brassica napus. The results suggest that water absorbing rate goes up in pre-time, subsequently down, lastly up again; and that the shell influences on seed's water absorbing and hampers pre-harvest sprouting.5. The experiments are conducted to study effects of exogenous ABA and GA3 on germination of seeds of Brassica napus. The results showed that 10³0mg.L^-1 GA3 could not obviously increase germination rate and germination vigor, have not...