Key Laboratory of National Forestry and Grassland Administration on Bamboo Resources and Utilization, China National Bamboo Research Center, Zhejiang, 310012, Hangzhou, China.
Key Laboratory of Mountain Surface Processes and Ecological Regulation, Institute of Mountain Hazards and Environment, Chinese Academy of Sciences, 610041, Chengdu, China.
BMC Plant Biol. 2021 Aug 18;21(1):379. doi: 10.1186/s12870-021-03159-3.
The decrease in Cunninghamia lanceolata (Lamb.) production on continuously planted soil is an essential problem. In this study, two-year-old seedlings of two cultivars (a normal cultivar, NC, and a super cultivar, SC) were grown in two types of soil (not planted (NP) soil; continuously planted (CP) soil) with three watering regimes, and the interactive effects on plant growth and physiological traits were investigated in a greenhouse experiment. The water contents of the soil in the control (CK) (normal water content), medium water content (MWC) and low water content (LWC) treatments reached 75-80 %, 45-50 % and 20-25 % of the field water capacity, respectively.
The results indicated that the CP soil had a negative effect on growth and physiological traits and that the LWC treatment caused even more severe and comprehensive negative effects. In both cultivars, the CP soil significantly decreased the height increment (HI), basal diameter increment (DI), dry matter accumulation (DMA), net photosynthetic rate (Pn), total chlorophyll content (TChl), carotenoid content (Caro) and photosynthetic nitrogen use efficiency (PNUE). Compared to the NP soil, the CP soil also decreased the proline and soluble protein contents, nitrogen use efficiency (NUE) and phosphorus use efficiency (PUE) and increased the nitrogen:phosphorus ratio in roots, stems and leaves. The LWC treatment decreased growth and photosynthesis, changed ecological stoichiometry, induced oxidative stress, promoted water use efficiency and damaged chloroplast ultrastructure. Significant increases in ascorbate peroxidase (APX), peroxidase (POD), soluble protein and proline contents were found in the LWC treatment. Compared with the NC, the SC was more tolerant to the CP soil and water stress, as indicated by the higher levels of DMA, Pn, and WUE. After exposure to the CP soil and watering regimes, the decreases in biomass accumulation and gas exchange were more pronounced.
The combination of drought and CP soil may have detrimental effects on C. lanceolata growth, and low water content enhances the impacts of CP soil stress on C. lanceolata seedlings. The superiority of the SC over the NC is significant in Chinese fir plantation soil. Therefore, continuously planted soil can be utilized to cultivate improved varieties of C. lanceolata and maintain water capacity. This can improve their growth and physiological performance to a certain extent.
在连续种植的土壤中，杉木产量下降是一个亟待解决的问题。本研究通过温室试验，以 2 年生的 2 个品种（普通品种 NC 和超级品种 SC）的幼苗为研究对象，在两种土壤（未种植土壤 NP 和连续种植土壤 CP）和三种水分处理（对照 CK（正常含水量）、中水分 MWC 和低水分 LWC）下，研究了它们对植物生长和生理特性的交互影响。在对照 CK（正常水分）、中水分 MWC 和低水分 LWC 处理中，土壤的含水量分别达到田间持水量的 75-80%、45-50%和 20-25%。
结果表明，CP 土壤对生长和生理特性有负面影响，而 LWC 处理则产生更严重和更全面的负面影响。在两个品种中，CP 土壤显著降低了苗高增量 HI、地径增量 DI、干物质积累 DMA、净光合速率 Pn、总叶绿素含量 TChl、类胡萝卜素含量 Caro 和光合氮利用效率 PNUE。与 NP 土壤相比，CP 土壤还降低了脯氨酸和可溶性蛋白含量、氮利用效率 NUE 和磷利用效率 PUE，并增加了根、茎和叶中的氮磷比。LWC 处理降低了生长和光合作用，改变了生态化学计量，诱导了氧化应激，促进了水分利用效率，并破坏了叶绿体的超微结构。在 LWC 处理中发现，抗坏血酸过氧化物酶 APX、过氧化物酶 POD、可溶性蛋白和脯氨酸含量显著增加。与 NC 相比，SC 对 CP 土壤和水分胁迫的耐受性更强，表现为 DMA、Pn 和 WUE 水平更高。在暴露于 CP 土壤和水分处理后，生物量积累和气体交换的减少更为明显。
干旱和 CP 土壤的结合可能对杉木的生长产生不利影响，而低水分含量加剧了 CP 土壤胁迫对杉木幼苗的影响。在杉木人工林土壤中，SC 优于 NC。因此，可以利用连续种植的土壤来培育改良的杉木品种，并保持土壤的水分容量。这可以在一定程度上提高它们的生长和生理性能。
