摘要
通过对二倍体野生蕉与三倍体威廉斯香蕉苗进行24h的7℃低温处理,测量其组织含水量(WC)、脯氨酸(Pro)含量、丙二醛(MDA)含量、总抗氧化能力的变化,同时测定其气体交换特征参数与叶绿素荧光参数,比较分析其变化特征。结果显示:低温处理下,威廉斯香蕉WC较其对照处理显著性下降,下降幅度为14.36%;低温与对照处理的野生蕉WC与对照处理的威廉斯香蕉WC保持相同水平。低温下威廉斯香蕉Pro含量(与干重比)较其对照显著下降,下降幅度为17.05%,而野生蕉Pro变化不显著。低温处理下的威廉斯香蕉MDA含量显著高于其他处理,而其总抗氧化能力也较其他处理显著下降。光系统Ⅱ最大光化学效率(Fv/Fm)以低温处理的威廉斯香蕉下降幅度最大,与其他处理相比达显著性差异。光强光合曲线中随光强的增加,低温处理的威廉斯香蕉净光合速率(Pn)增加幅度低于对照处理,低温与对照处理的野生蕉随光强增加其Pn保持相同幅度的增加,且增加幅度居于对照与低温处理的威廉斯香蕉之间。总之,三倍体威廉斯香蕉对冷害更为敏感,其膜系统氧化加剧、脯氨酸含量降低、失水量增加,总抗氧化能力降低,光系统Ⅱ最大光化学效率明显受抑制、净光合速率明显下降;然而,同样低温处理下二倍体野生蕉则表现出与对照相似的生理状态,因此可认为野生蕉作为具抗寒性种质可作为抗寒育种的重要材料。
The seedlings of diploid wild banana and triploid Williams banana were treated with low temperature of 7℃ for 24 h, and then the tissue water content （WC）, proline （Pro） content, malondialdehyde （MDA） content, total antioxidant capacity （DPPH scavenging capability） , gas exchange parameters and chlorophyll fluorescence parameters were determined. The results showed that there were no significant differences between the low temperature treatments and the control in the physiological indexes of diploid wild banana. The WC in the Williams banana under low temperature treatment was 14.36% lower than that under the control condition. The Pro content （per dry weight） of Williams banana under low temperature treatment decreased by 17.05% in comparison with the control sample while the MDA content of the former was significant higher than that in the other treatment, and the total antioxidant capacity of the former sample was significant lower than that in the other treatment. Maximum photochemical efficiency of PSII （Fv/ Fm） of Williams banana in low temperature decreased obviously, and the ascending extent of net photosynthetic rate （Pn） in photosynthetic Pn-PPFD curve was the lowest, and that in the control group of Williams was the highest, and the differences in ascending extent of Pn of diploid wild banana between low temperature treatment and the control was not obvious. In summary, the triploid Williams banana was more easily affected by chilling injury, i. e. , its cell membrane system oxidation increased; Pro content decreased, total antioxidant capacity decreased, and gas exchange parameters such as Fv/Fm and Pn significantly decreased while PSII was obviously inhibited. However, the diploid wild banana at the same low temperature displayed a similar physiological reactions with the control ones. So the wild banana can be considered as a cold resistance germplasm which can be an important material of cold-resistance breeding.
出处
《核农学报》
CAS
CSCD
北大核心
2014年第8期1528-1533,共6页
Journal of Nuclear Agricultural Sciences
基金
广西自然科学基金项目(2013GXNSFBB053003)
关键词
香蕉苗
冷胁迫
生理响应
品种
Banana plantlet
Chilling stress
Physiological responses
Cultivar
