上海地区甘蓝型低芥酸油菜的保纯技术探讨

APPROACH TO QUALITY-KEEPING TECHNIQUES OF SINGLE LOW RAPESEED CULTIVARS(Brassica napus L.)IN SHANGHAI'S ECOLOGICAL CONDITIONS

在上海的生态和种植条件下,对甘蓝型低芥酸油菜的保纯技术进行了探讨。结果表明,甘蓝型油菜的异交率为17.3%～29.0%,不同基因型的油菜品种(系)其自然异交率不同。在一定地域范围内,品种间种植地相隔的距离越大,异交率越小,但超过一定范围其异交率变化不明显。单株套袋自交保纯效果最好,网罩隔离和自然隔离保纯效果相似。低芥酸油菜品种与常规品种间种植地相距越远,后代种子的芥酸含量升幅越小。低芥酸油菜品种与常规油菜相隔50m 以上成片种植,后代群体种子芥酸含量升幅为0～2.17个百分点;成片相邻或相间种植,其后代群体种子芥酸含量升幅为2.82～3.70个百分点。从而得出,生产低芥酸油菜,成片隔离种植的生产用种芥酸含量须低于2.5%。成片相邻或相间种植的应低于1%,这样才能有效控制商品种子芥酸含量低于5%。

The quality-keeping techniques of single low rapeseed cultivars (B.napus L.) were studied in Shanghai's ecological conditions.The result showed that the average out- crossing rate of B.napus L.was 17.3%～29.0%.But different genotypes of rapeseed had dif- ferent outcrossing rates.The effect of single plant self-crossing on keeping rapeseed quality was the best among the four tested methods.The effects of nylon mosquito-net isolation and natural isolation on keeping rapeseed quality were similar.The erucic acid content of filial seeds increased by about 0～2.17 percent and 2.82～3.70 percent when the single low rape- seed cultivars were planted with commercial rapeseed cultivars by isolation space of more than 50 metres and no isolation space,respectively.The result fully proved that the erucic acid content of stock seeds must be below 2.5% when the single low rapeseed cultivars were planted by isolation space for commercial seed production;under otherwise planting condi- tions,the erucic acid content of stock seeds must be below 1%.Under these conditions the erucic acid content of commercial seeds can keep below 5%.