《植物生理学报》 2017, 53(3): 437-444

甘蔗不同组织联合固氮能力评价

胡浩南¹, 敖俊华², 黄晓财¹, 李欣欣^3,*, 廖红³

¹华南农业大学农学院, 广州510642; ²广州甘蔗糖业研究所, 广州510642; ³福建农林大学根系生物学研究中心, 福州350002

通信作者：李欣欣；E-mail: lixinxin0476@163.com

摘　要：

以甘蔗栽培品种ROC22和含有野生斑茅蔗血缘的BC2-32为材料, 通过乙炔还原法评价了甘蔗不同组织的固氮能力。结果显示, 在分蘖期, ROC22根系的固氮酶活性较高, 可能是联合固氮的主要器官; 在伸长期, 利用以蔗糖为碳源的LGI、SNX和SH培养基培养, 甘蔗叶片的固氮酶活性最高; 以苹果酸为碳源的JNFb和Mal处理, 积累一定糖分的+4和+5茎的固氮酶活性较高, 暗示了叶片主要定殖以蔗糖为碳源的内生固氮菌, 是伸长期固氮效率最高的部位, 其次为蔗茎。ROC22根系在SH培养条件下的固氮酶活性比BC2-32高25倍, 说明ROC22根系中含有某些优势内生固氮菌; 而两种甘蔗不同叶和蔗茎的固氮酶活性在伸长期表现较为相似的趋势, 说明ROC22和BC2-32中定殖的主要是以蔗糖为碳源, 较为保守且专性较强的内生固氮菌。

关键词：甘蔗; 联合固氮; 固氮酶活性; 培养基; 组织

收稿：2016-11-14   修定：2017-02-08

资助：福建省高效联合基础研究项目(2017J01603)。

Evaluation on associative nitrogen fixation capability in different tissues of sugarcane

HU Hao-Nan¹, AO Jun-Hua², HUANG Xiao-Cai¹, LI Xin-Xin^3,*, LIAO Hong³

¹College of Agriculture, South China Agricultural University, Guangzhou 510642, China; ²Guangzhou Sugarcane Industry Research Institute, Guangzhou 510642, China; ³Root Biology Center, Fujian Agriculture and Forestry University, Fuzhou 350002, China

Corresponding author: LI Xin-Xin; E-mail: lixinxin0476@163.com

Abstract:

Using two sugarcane varieties including ROC22 cultivar and BC2-32 which harboring blood lineage from Erianthus arundinaceus as plant materials, an acetylene reduction method was employed to evaluate the nitrogen (N₂) fixation capability in different tissues of sugarcane. Results showed that, ROC22 had the higher nitrogenase activities in roots than other tissues, and thus might be the primary N₂ fixation organ at tillering stage. While sugarcane leaves had the highest nitrogenase activities when separately cultured by LGI, SNX and SH which providing with sucrose as the carbon source, and +4 and +5 stem with certain sugar accumulation showed relatively high nitrogenase activity when using JNFb and Mal which malate as carbon, suggested that sugarcane leaves predominantly colonized by sucrose-preferred endophytic diazotroph and possessing the highest N2 fixation efficiency, and followed by sugarcane stalks at elongation stage. The nitrogenase activities in roots of ROC22 are more than 25 times than BC2-32 by using SH culture medium, elucidated that there are some N₂ fixation efficient and dominant azotobacter in ROC22, while it is showed the similar tendency of nitrogenase activities in different leaves and stalks in both two sugarcane varieties at elongation stage, indicated that ROC22 and BC2-32 mainly colonized by some conserved and specific strains of endophytic diazotroph which prefer sucrose as carbon source.

Key words: sugarcane; associative nitrogen fixation; nitrogenase activity; culture medium; tissue