初花期干旱对甘蓝型油菜生理和农艺性状的影响

初花期是油菜生殖生长的关键时期。为研究干旱对这一时期油菜的影响,在人工控水条件下(当土壤含水量为田间持水量的45%~50%时计为干旱胁迫开始,处理持续10d,然后复水;CK正常灌水,保持田间持水量在80%~85%),利用4个具有不同耐旱性的甘蓝型油菜品种浔油8号、阳光2009、浙油50和华油杂13号,研究生理特性、农艺性状和产量的变化。结果表明,在干旱胁迫10d后,耐旱性品种(浔油8号和阳光2009)的叶片SPAD值、可溶性蛋白质、MDA含量变幅不大,可溶性糖含量小幅下降,CAT酶活性小幅增加,游离脯氨酸含量显著增加(其中浔油8号和阳光2009分别比对照增加了4.1倍和2.9倍)。相比之下,敏感性品种(浙油50和华油杂13号)的叶片SPAD值、可溶性蛋白质和可溶性糖含量均显著减少,MDA含量显著增加,CAT酶活性变幅不大,游离脯氨酸含量显著增加,但增幅小于耐旱品种。初花期干旱影响油菜的主要农艺性状和产量,表现为敏感性品种的株高、一次分枝数、相对分枝高、主花序长、主花序角果数、角果长、单株角果数、角果粒数和单株产量均显著下降,而且降幅明显大于耐旱性品种。

Drought effects on physiological and agronomic traits of rapeseed (Brassica napus L.) at initial blooming stage

 Initial blooming is the key stage of rapeseed growth. To understand the effect of drought on rapeseed at this stage, 10 days of drought (beginning from the day when field moisture was 45-50%) was conducted in pots under rain-proof shelter during initial flowering period. Normal irrigation was controlled (with 80-85% field moisture). 4 cultivars were used, including 2 drought-resistant Brassica napus L. cv Xunyou 8 and Yanguang 2009, and 2 drought-sensitive cv Zheyou 50 and Huayouza 13. After 10d-drought, resistant cultivars’ leaf SPAD value, soluble protein and malondialdelyde (MDA) content changed little, soluble sugar content declined slightly, catalase (CAT) activity increased slightly, while free proline significantly increased by 2.9-4.1 folds. On the contrary, sensitive cultivars’ physiology indicators changed significantly, including decreased SPAD value, soluble protein and soluble sugar contents, and increased free proline (but less than resistant cultivars). The drought stress had significant impacts on agronomic traits and yield. For sensitive cultivars, plant height, primary branches, inflorescence length, pods number on main inflorescence, pod length, pods per plant, seeds per pod and yield decreased significantly. But for resistant cultivars, the decrease rate was much lower.