西辽河平原矮秆蓖麻杂交种抗氧化酶活性、产量与油分含量对氮肥水平的响应

Responses of antioxidant enzyme activities,yield,and oil content to nitrogen fertilizer in dwarf castor hybrids in the Xiliaohe Plain

采用大田随机区组试验设计,以矮秆蓖麻杂交种通蓖11号为试材,以高秆杂交种通蓖9号为对照,在N 0、60、120、180 kg/hm^(2) 4个氮肥用量处理下,探讨灌浆期间叶片抗氧化酶活性、产量和油分含量对氮肥水平的响应。结果表明,在0~120 kg/hm^(2)施氮水平范围内,随着氮肥水平的提高,2品种的超氧化物歧化酶(SOD)、过氧化物酶(POD)和过氧化氢酶(CAT)活性不断增强,丙二醛(MDA)含量则持续下降。当施氮水平提高到180 kg/hm^(2)时,SOD、POD、CAT活性不再升高,反而下降,MDA含量则略有上升。在各个氮肥水平和灌浆阶段通蓖11号SOD、POD、CAT活性均高于通蓖9号,MDA含量均低于通蓖9号;在低氮水平处理下,2品种间大部分差异不显著;在高氮水平处理下,大部分差异显著。随着灌浆进程,SOD、POD活性呈单峰曲线变化,但通蓖11号的峰值较通蓖9号有所延迟。CAT活性呈下降趋势,MDA含量呈上升趋势。各处理籽粒产量、油分含量与抗氧化酶活性趋势相同。相关分析结果表明,籽粒产量和油分含量与SOD、POD、CAT活性呈正相关关系,与MDA含量呈负相关关系。灌浆前期,花后10 d通蓖9号SOD、POD和CAT活性与籽粒重的相关关系达显著或极显著水平,通蓖11号则达显著水平。花后20 d通蓖9号SOD、POD和CAT活性与籽粒重的相关关系未达显著水平,通蓖11号则达显著水平。灌浆中期,通蓖11号SOD、POD活性与油分含量呈显著正相关关系,而通蓖9号油分含量仅与POD活性呈显著正相关关系,与SOD和CAT相关关系未达显著水平。说明适量施用氮肥可以提高蓖麻主茎叶片抗氧化酶活性,降低MDA含量,但通蓖11号保护酶活性对氮肥的生理响应更积极,具有更强的改善细胞中活性氧产生与清除之间的平衡能力,这是其籽粒产量和油分含量高于通蓖9号的生理原因。120 kg/hm^(2)氮肥用量是通蓖11号在西辽河平原取得优质高产的最佳施肥水平。

The response of leaf antioxidant enzyme activity,yield and oil content to nitrogen fertilizer level during grain filling was investigated by using field experiment with randomized block design,taking dwarf castor hybrid Tongbi 11 as test material and high-stalk hybrid Tongbi 9 as control under 4 nitrogen fertilizer treatments of N 0,60,120,180 kg/hm^(2). The results showed that the activities of superoxide dismutase(SOD),peroxidase(POD) and catalase(CAT) increased continuously and the content of malondialdehyde(MDA) decreased continuously with the increase of nitrogen application level in the range of 0 ~ 120 kg/hm^(2). When nitrogen application level increased to 180 kg/hm^(2),SOD,POD,CAT activities decreased,while MDA content slightly increased. The activities of SOD,POD and CAT of Tongbi 11 were higher than those of Tongbi 9 at various nitrogen fertilizer levels and filling stage,and the MDA content was lower than that of Tongbi 9. Under low nitrogen level treatment,most of the differences between the two varieties were not significant,while under high nitrogen level treatment,most of the differences were significant. With the grouting progress,SOD and POD activities showed a single peak curve,but the peak value of Tongbi 11 was delayed compared with Tongbi 9. CAT activity decreased and MDA content increased. Grain yield,oil content and antioxidant enzyme activity of each treatment showed the same trend. Correlation analysis results showed that grain yield and oil content were positively correlated with SOD,POD and CAT activities,and negatively correlated with MDA content. In the early stage of filling,the correlation between SOD,POD and CAT activities of Tongbi 9 and grain weight reached significant or extremely significant level at 10 d after anthesis,while Tongbi 11 reached a significant level. The correlation between SOD,POD and CAT activities of Tongbi 9 and grain weight did not reach a significant level at 20 d after anthesis,but those of Tongbi 11 reached a significant level. In the middle stage of filling,the SOD and POD activities of Tongbi 11 were significantly positively correlated with oil content,while the oil content of Tongbi 9 was only significantly positively correlated with POD activity,and the correlation with SOD and CAT was not significant. The results showed that proper application of nitrogen fertilizer could improve antioxidant enzyme activity and reduce MDA content in castor main stem leaves. The protective enzyme activity of Tongbi 11 has a more positive physiological response to nitrogen fertilizer and has a stronger ability to improve the balance between production and removal of active oxygen in cells,which is the physiological reason why its grain yield and oil content are higher than those of Tongbi 9. The application rate of 120 kg/hm^(2) nitrogen fertilizer is the best fertilization level for Tongbi 11 to obtain high quality and high yield in Xiliaohe plain.