中文摘要：

在4个生态区种植11个不同抗寒性白菜型冬油菜品种,探讨北移种植后冬油菜生育期进程、农艺性状、品质等的变化特征及与主要生态因子间的相关性。结果表明：与原种植区（天水）相比,冬油菜北移后其生育期进程发生明显改变,主要表现在冬前生育期缩短,越冬期延长;越冬后返青期～成熟期生育期总天数不变,但早期（返青期～终花期）生育期进程加快,而角层期延长。北移种植后冬油菜株高、分枝部位降低,主花序变短、单株角果数减少,分枝数增加,株型变差;角粒数、千粒重增加,角、粒性状改善。含油量、油酸、亚麻酸、芥酸含量增加,亚油酸、廿碳烯酸、硫苷含量降低;油酸、亚麻酸含量与纬度、海拔呈显著正相关,与降雨量、年均温度、最冷月温度呈显著负相关;廿碳烯酸、硫苷与油酸、亚麻酸表现相反。冬油菜北移后株型变差,角、粒性状改善;冬前生育期变短,越冬期延长,返青后生育期加快,而角层期延长,有利于粒重增加;籽粒含油量增加,高纬度、高海拔有利于油酸、亚麻酸积累,而高降雨量、低温有利于廿碳烯酸积累。

英文摘要：

Eleven winter rapeseed（ Brassica campestris L.） cultivars with different levels of cold resistance were grown in four ecological regions in Gansu province,northwest China. Changes in the progression of growth,agronomic traits,and quality of northward-expanded rapeseed plants were determined,and their correlations with major regional ecological factors were evaluated,in order to provide a reference for northward expansion and cultivation of this crop. Compared with those in the original growing area（ Tianshui）,northward- expanded rapeseed plants exhibited great changes in the progression of growth,as reflected mainly by the significantly shortened growth period in pre-winter and prolonged over-wintering period. Total growth period（ number of days） between seedling establishment and maturation stages after wintering was not changed. However,early growth process during seedling establishment to final flower stage was accelerated,while the podding stage was prolonged. Additionally,northward-expanded rapeseed cultivars had taller plant height and lower branch part,with shorter primary inflorescence than the control plants. The former had a reduced number of siliques per plant but an increased number of branches,showing poor plant morphology. The number of seeds per silique and thousand seed weight were increased,suggesting improvements in silique and seed traits. Seed oil content as well as oleic,linolenic,and erucic acid contents became increased,which coincided with reductions in linoleic,eicosenoic acid,and thioglycoside contents. Seed oleic and linolenic acid contents were positively correlated with latitude and altitude,and negatively correlated with rainfall,mean annual temperature,and temperature of the coldest month,whereas gadoleic acid and thioglycoside contents showed the opposite. In conclusion,northward expansion ofwinter rapeseed cultivars resulted in the poor plant morphology but improved silique and seed traits; during the progression of plant growth,the pre-winter growth period was shorten