Abstract: Brassica napus, an important oil crop, is extraordinarily sensitive to low phosphorus (P) deficiency. In order to clarify the effects of low P deficiency on seed yield and quality traits of B. napus, 9 quality traits and seed yield per plant of natural population, containing 189 B. napus varieties were investigated by field trials under normal P and low P conditions. The results showed that: ① There were significant differences for the phenotypic variation among all traits of B. napus under both P treatments, and the variation coefficient of eicosenoic acid, oleic acid and single plant yield were greater. P deficiency impairs yield of B. napus, but had relatively smaller effects on seed quality. ② No difference could be observed for the correlations among all quality traits under both P levels, but P deficiency could significantly decrease the correlation between yield and 3 quality traits including protein, water and oil content under P stress condition. ③ The effects of P deprivation on seed quality traits were different among various B. napus cultivars. Generally, contents of oil, water, oleic acid and linolenic acid were less influenced by low P stress compared to that of other quality traits. The linoleic acid and palmitic acid contents of over 75% cultivars decreased under low P stress, while the eicosenoic acid and oleic contents of over 60% cultivars were increased under the same condition. ④ Based on the oil content and single plant seed yield of the 187 cultivars under normal and low P levels, 6 varieties were selected as candidates for P tolerance. These results provided useful information for further unravel the genotypic difference and genetic mechanism for quality traits under low P deficiency in Brassica napus.

Key words: Brassica napus, low phosphorus stress, single plant yield, quality trait, screen of germplasm

摘要： 甘蓝型油菜作为重要的油料作物，对缺磷敏感。为了分析低磷胁迫对甘蓝型油菜自然品种产量及品质的影响，通过大田实验调查了187份甘蓝型油菜自然品种在正常磷和低磷胁迫条件下种子中9个品质性状及单株产量的变化。结果表明：①两处理条件下自然群体各性状变异范围差异较大，其中20碳烯酸、油酸和单株产量的变异系数较大。缺磷对群体产量的影响较大，而对品质性状的影响相对较小；②低磷胁迫不影响群体各品质性状间的相关性，但会显著降低含油量、蛋白质及水分含量与单株产量间的相关性；③低磷胁迫对品质性状的影响在品种间表现出不同的趋势。总体而言，含油量、水分、油酸和亚麻酸等受低磷胁迫影响的趋势不明显，75%以上品种的亚油酸和棕榈酸含量下降，60%以上品种的20碳烯酸和硬脂酸含量上升；④以磷正常和低磷条件下的含油量和单株产量为指标，挑选出6个耐低磷胁迫的优异种质。上述结果为深入开展低磷胁迫条件下油菜品质性状的基因型差异及遗传调控机制提供了基础。

关键词: 甘蓝型油菜, 低磷胁迫, 单株产量, 品质性状, 种质筛选