石灰岩山地根瘤菌对台湾相思苗木生长效应

从石灰岩山地不同立地条件的台湾相思林分中采集根瘤并分离获得12株根瘤菌,将其接种到台湾相思盆栽苗木中,5个月后测量苗木的株高、地径、生物量及根瘤结瘤情况。试验结果表明:①在石灰岩山地的台湾相思林分中,根瘤数量较多的是中、下坡,最少的是下坡;单个根瘤平均质量最重的是中坡,上坡和下坡次之,表明石灰岩山地的中坡最适合根瘤菌生长。②供试的12株菌株回接到台湾相思苗木后能全部侵染苗木根部并结成有效根瘤;与对照比较,菌株回接都不同程度地促进台湾相思苗木的株高、地径、生物量的增长,增长幅度分别为1.7%~39.0%、1.7%~18.1%和21.4%~135.7%;根瘤生物量也比对照增长3.04~12.94倍。综合分析结果表明,台4、台10菌株为优良菌株。

The effects of the karst Rhizobia on the growth of Acacia confusa seedlings

Total 12 Rhizobia strains were effectively selected from the stands of Acacia confusa in different slope sites of limestone region,then inoculated to the seedlings of Acacia confusa.The height,ground diameter,biomass and the ratio of nodulation were determined after 5 months treatment.The results showed: ①In the stands of Acacia confusa at different limestone slope sites,larger number of Rhizobia exited in the middle-slope and the downslope,less number in the upslope;As for the mean weight of the Rhizobia nodulation, larger exited in the middle slope,less in the upslope and downslope.It meant that the conditions of middle-slope were preferable to the growth of Rhizobia.②The inoculation of the 12 Rhizobia strains can effectively produce the nodules in the seedlings of A.confusa seedlings.Compared to the CK treatment,the seedling height increased 1.7%～39.0%,the ground diameter as 1.7%～18.1%,total biomass as 21.4%～135.7%,while the nodulation increased as 3.04～12.94 times.Comprehensively, the 4 and 10 strains were selected as the super strains.