摘要
通过向青色荧光蛋白(CFP)标记的两种根瘤菌菌液Ensifer meliloti LZgn5f(gn5f)和Ensifer meliloti 12531f(12531f)内添加不同浓度硼并接种于苜蓿幼苗根部,研究硼对荧光标记根瘤菌在甘农5号紫花苜蓿幼苗体内运移和定殖的动态变化及接种对苜蓿幼苗生长的影响。结果表明,添加1 mg/L硼较利于12531f生长,100 mg/L硼较利于gn5f生长。添加适宜浓度硼对苜蓿幼苗体内荧光标记根瘤菌运移和定殖具有促进作用,两种荧光标记根瘤菌在根部定殖数量较多,其中添加100 mg/L硼15 d时根部12531f数量最高,达2184.99 cfu/g,添加0.5 mg/L硼60 d时gn5f数量最高,达58307.11 cfu/g;同时可向地上运移,主要运移并定殖于下部茎叶内,1 mg/L硼利于12531f在下部茎叶内定殖,100 mg/L硼利于gn5f在下部茎内定殖。对照各部位未检测到两种荧光标记根瘤菌。添加硼处理的单株结瘤数、单株根瘤重、单株叶片数、株高、根长、地上鲜重、地上干重、根鲜重和根干重均高出对照和单独接菌处理,1 mg/L硼+12531f处理高出对照和单独接菌处理,范围在21.31%~909.28%之间;100 mg/L硼+gn5f处理高出对照和单独接菌处理,范围在15.07%~1424.24%之间;虽然单独接种12531f抑制了叶绿素的形成,但添加1 mg/L硼后其含量则升高,分别显著高出对照和单独接菌处理18.31%和36.86%(P<0.05),而接种gn5f则促进了叶绿素的合成,添加100 mg/L硼后含量分别显著高出对照和单独接种处理24.41%和12.92%(P<0.05)。因此,1 mg/L硼与12531f混合接种,100 mg/L硼与gn5f混合接种对根瘤菌在苜蓿幼苗体内运移和定殖及对幼苗的生长具有促进作用,为苜蓿种植提供了依据。
The effect of boron on the migration and colonization of rhizobia in Gannong No.5 alfalfa（Medicago sativa Gannong No.5） tissues and subsequently seedling growth were investigated by root drenching using two cyan fluorescent protein（CFP） tagged rhizobia; Ensifer meliloti 12531f（12531f） and Ensifer meliloti GN5f（gn5f） containing different boron concentrations.The results showed that the best supplementation levels were less than 1 and 100 mg/L boron for12531 f and gn5 f respectively.The optimum boron level enhanced the colonization of both rhizobia in alfalfa roots; colonization densities of 2184.99 and 58307.11 cfu/g were achieved by using 100 mg/L boron co-inoculated 12531 f and 0.5 mg/L boron co-inoculated gn5 f,respectively.Rhizobia were able to migrate to the aerial tissues and colonize lower stems and leaves through application of 1 mg/L boron co-inoculated 12531 f and 100 mg/L boron co-inoculated gn5 f,respectively.No fluorescent tagged rhizobia were detected in the control treatment.Individual plant root nodule number,nodule weight,leaf number,plant height,root length,aerial fresh weight,aerial dry weight,root fresh weight and root dry weight were increased by 21.31%-909.28% for the 1 mg/L boron co-inoculated 12531 f treatment compared with control and zero boron innoculation.These traits were increased by 15.07%-1424.24% for the 100 mg/L boron co-inoculated gn5 f treatment compared with control and zero boron inoculation treatments.Leaf chlorophyll content was reduced by 12531 f without boron whereas 1 mg/L boron co-inoculated 12531 f significantly increased the leaf chlorophyll content by 18.31% and 36.86% compared with the control and zero boron inoculation,respectively（P〈0.05）.Boron supplemented gn5 f enhanced the leaf chlorophyll content; 100 mg/L boron co-inoculated gn5 f increased leaf chlorophyll content by 24.41% and 12.92% compared with control and zero born inoculation,respectively（P〈0.05）.The results suggest that 1 mg/L boron co-inoculation with 12531 f,100 mg/L boron
出处
《草业学报》
CSCD
北大核心
2017年第4期120-133,共14页
Acta Prataculturae Sinica
基金
国家自然科学基金项目(31560666)资助
关键词
荧光标记根瘤菌
硼
紫花苜蓿
运移和定殖
促生效应
fluorescent tagged rhizobia
boron
Medicago sativa
migration and colonization
growth promoting
