摘要
试验从银荆树、刺槐、银合欢和山毛豆根部分离的4种根瘤菌分别接种到木豆、银合欢、滇合欢的1年生幼苗上,采用PEG(聚乙二醇6000)配置成水势分别为-3 bar、-9 bar、-15 bar的水溶液对木豆苗木进行干旱胁迫,银合欢、滇合欢在-3 bar条件下进行干旱胁迫,约14 h后测定苗木的光合特性。结果表明,苗木结瘤可提高净光合速率,延长高光效时间,不同菌株和不同树种对干旱胁迫下的净光合速率影响显著。接种银合欢根瘤菌的木豆和滇合欢苗木,接种银荆树根瘤菌的银合欢苗木,都有着较高的净光合速率,而接种山毛豆菌株的苗木净光合速率较低。在不同干旱胁迫下,木豆结瘤苗木的净光合速率表现为-9 bar>-3 bar>-15 bar;结瘤苗木在相同-3 bar干旱胁迫下,银合欢、木豆、滇合欢的净光合速率日均值依次递减。但各处理14∶00时的水分利用效率与净光合速率和14∶00时的气孔导度表现相反,主要由于栽培基质为贫瘠的河沙,在干旱胁迫下,气孔导度大,光合及蒸发量也大。
Four rhizobia isolated from the roots of Acacia dealbata, Robinia pseudoacacia, Tephrosia candida were inoculated to 1 year old seedlings of Cajanus cajan, Leucaena leucocephala and Albizia simeonis to cultivate the nod- ulated seedlings. Three concentrations （ -15 bar, -9 bar, -3bar ） of PEG 6000 solution were used to impose drought stress treatments to the seedlings of C. cajan, while - 3bar was used to the seedlings of L. leucocephala and A. simeonis. Photosynthetic characteristics of the seedlings were measured after 14 h. The results showed that inoc- ulation could accelerate net photosynthesis rate （Pn） and prolong high photosynthetic efficiency time. Under drought stress, both rhizobia strain and plant species had significant effects on Pn. The seedlings of C. cajan and A. simeonis inoculated with the rhizobium of L. leucocephala, and the seedlings of L. leucocephala inoculated with the rhizobium of A. dealbata had high Pn but the seedlings inoculated with the rhizobium of T. candida had low Pn. Under different drought stress conditions, the order of Pn of nodulated C. cajan seedlings was - 9 bar 〉 - 3 bar 〉 - 15 bar; under the same condition （ -3 bar）, the order of Pn was L. leucocephala 〉 C. cajan 〉A. simeonis. Wa- ter used rate and Pn of all treatments were opposite to stomatal conductance at 14 ： 00, which was mainly caused by nutrient poor sand used in the experiment and high evaporation.
出处
《西部林业科学》
CAS
北大核心
2013年第2期82-87,共6页
Journal of West China Forestry Science
基金
国家自然科学基金(31260175和30760199)
关键词
豆科结瘤苗木
干旱胁迫
净光合速率
水分利用效率
气孔导度
Leguminosae
nodulated seedlings
drought stress
net photosynthesis rate
water used rate
stomatal conductance
