■杉木(Cunninghamialanceolata)人工林的连续建立跨越多代,导致土壤磷(P)对树木生长的影响有限。这一挑战对维护杉木的可持续管理构成了重大障碍。
■研究不同供磷处理下丛枝菌根真菌(AMF)对杉木生长和生理特性的影响。我们于2019年3月至2019年6月在福建农林大学林学院大棚内进行了杉木1年半生幼苗室内盆栽模拟实验,两个P水平处理组包括正常P供应处理(1.0mmolL-1KH2PO4,P1)和无P供应处理(0mmolL-1KH2PO4,P0)。P0和P1接种真菌真菌(F.m)或根瘤菌内(R.i)或未接种AMF处理。AMF在根系中的定殖率,苗高(SH),根领直径(RCD)增长,叶绿素(Chl)光合特性,酶活性,并对杉木内源激素含量进行了估算。
■结果表明,在P0时,杉木幼苗根中F.m的定殖率最高,达85.14%,是P1的1.66倍。在P0和P1处理下,用F.m或R.i接种促进SH生长,R.i治疗的SH是F.m治疗的1.38倍和1.05倍,分别。在P1治疗中,用F.m或R.i接种根会抑制RCD的生长。R.i比F.m.更积极地抑制RCD生长。在P0治疗中,根接种F.m和R.i降低了缺磷对RCD的抑制作用。此时,F.m之间的RCD没有显着差异,R.i和CK处理(p<0.05)。AMF接种增加了Fm,Fv,Fv/Fm,供试杉木幼苗叶绿素荧光响应过程中的Fv/Fo。在两个磷供应水平下,不同处理组杉木幼苗Fv和Fm的变化趋势为F.m>R.i>CK。在P0处理下,Fv值分别为235.86、221.86和147.71。Fm值分别为287.57、275.71和201.57。在一定程度上提高了叶片抗氧化酶活性,降低了叶片丙二醛(MDA)含量。
■得出的结论是,AMF可以增强寄主的光合能力,调节内源激素在植物中的分布,并通过增加抗氧化酶的活性来促进植物生长。当P供应不足时,AMF对植物更有帮助,R.i在缓解杉木P饥饿胁迫方面比F.m更有效。
UNASSIGNED: The continuous establishment of Chinese fir (Cunninghamia lanceolata) plantations across multiple generations has led to the limited impact of soil phosphorus (P) on tree growth. This challenge poses a significant obstacle in maintaining the sustainable management of Chinese fir.
UNASSIGNED: To investigate the effects of Arbuscular mycorrhizal fungi (AMF) on the growth and physiological characteristics of Chinese fir under different P supply treatments. We conducted an indoor pot simulation experiment in the greenhouse of the Forestry College of Fujian Agriculture and Forestry University with one-and-half-year-old seedlings of Chinese fir from March 2019 to June 2019, with the two P level treatment groups included a normal P supply treatment (1.0 mmol L-1 KH2PO4, P1) and a no P supply treatment (0 mmol L-1 KH2PO4, P0). P0 and P1 were inoculated with Funneliformis mosseae (F.m) or Rhizophagus intraradices (R.i) or not inoculated with AMF treatment. The AMF colonization rate in the root system, seedling height (SH), root collar diameter (RCD) growth, chlorophyll (Chl) photosynthetic characteristics, enzyme activities, and endogenous hormone contents of Chinese fir were estimated.
UNASSIGNED: The results showed that the colonization rate of F.m in the roots of Chinese fir seedlings was the highest at P0, up to 85.14%, which was 1.66 times that of P1. Under P0 and P1 treatment, root inoculation with either F.m or R.i promoted SH growth, the SH of R.i treatment was 1.38 times and 1.05 times that of F.m treatment, respectively. In the P1 treatment, root inoculation with either F.m or R.i inhibited RCD growth. R.i inhibited RCD growth more aggressively than F.m. In the P0 treatment, root inoculation with F.m and R.i reduced the inhibitory effect of phosphorus deficiency on RCD. At this time, there was no significant difference in RCD between F.m, R.i and CK treatments (p < 0.05). AMF inoculation increased Fm, Fv, Fv/Fm, and Fv/Fo during the chlorophyll fluorescence response in the tested Chinese fir seedlings. Under the two phosphorus supply levels, the trend of Fv and Fm of Chinese fir seedlings in different treatment groups was F.m > R.i > CK. Under P0 treatment, The values of Fv were 235.86, 221.86 and 147.71, respectively. The values of Fm were 287.57, 275.71 and 201.57, respectively. It increased the antioxidant enzyme activity and reduced the leaf\'s malondialdehyde (MDA) content to a certain extent.
UNASSIGNED: It is concluded that AMF can enhance the photosynthetic capacity of the host, regulate the distribution of endogenous hormones in plants, and promote plant growth by increasing the activity of antioxidant enzymes. When the P supply is insufficient, AMF is more helpful to plants, and R.i is more effective than F.m in alleviating P starvation stress in Chinese fir.