关键词: 甘蓝型油菜, 低磷胁迫, 单株产量, 品质性状, 种质筛选

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