丛枝菌根真菌对桑树(Morus alba)地上部分的促进作用

Positive effects of arbuscular mycorrhizal fungi(AMF) on the aboveground part of Morus alba

为揭示接种丛枝菌根真菌(arbuscular mycorrhizal fungi, AMF)与桑树(Morus alba)地上部分(茎、叶)生长的内在联系,本研究以等体积混合的泥土、河沙和蛭石为培养基质,研究接种丛枝菌根真菌摩西斗管囊霉(Funneliformismosseae)对我国西南常栽桑树品种‘桂桑优62’幼苗的形态特征、生物量积累与分配、气体交换、叶绿素含量和营养元素含量方面的影响,进而揭示AMF对桑树幼苗地上部分生长的影响。结果发现:与对照相比,接种AMF后显著促进了桑树幼苗的形态生长和地上生物量的积累,植株的叶片数、株高、基径、总叶面积、茎干质量、叶干质量、总干质量和叶干质量分数分别增加了87.72%、193.88%、224.44%、133.68%、57.67%、131.29%、68.87%和40.00%。此外,接种AMF后净光合速率(Pn)、叶绿素b、总叶绿素以及叶片的碳(C)、氮(N)、磷(P)的含量也显著增加。但AMF对根系形态与根干质量的影响不显著。上述研究表明, AMF可以通过显著增加桑树叶的叶绿素和C、N、P的含量进而提高净光合速率,最终促进桑树幼苗茎和叶的生长。研究结果可为我国西南地区桑树的高产种植提供参考。

To investigate effects of arbuscular mycorrhizal fungi(AMF) on shoot growth of Morus alba, we grow the mulberry seedlings ’Gui-sang-you 62’, a widely cultivated plant in Southwest China, on homogenized soil substrate(equal volume of soil, river sand and vermiculite) with inoculating Funneliformis mosseae. The differences in morphological characteristics, biomass accumulation and allocation, gas exchange, concentrations of chlorophyll and nutrient of M. alba were compared. The results showed that the leaf numbers, height, basal diameter, total leaf area, dry mass of stem, leaf and total seedling, and the ratio of leaf and total dry mass were significantly higher under inoculating with AMF than without AMF inoculating, and these traits respectively increased by 87.72%, 193.88%, 224.44%, 133.68%, 57.67%, 131.29%, 68.87%, 40.00%. In addition, AMF also increased net photosynthetic rate, chlorophyll b, total chlorophyll and leaf carbon(C), nitrogen(N), phosphorus(P) concentrations. However, the morphology and dry mass of roots did not significantly affect by AMF. This study indicated that AMF can improve the photosynthetic rate by increasing the content of chlorophyll, C, N and P, and then promoting the growth of stems and leaves of M. alba seedlings. These results could contribute to improve the yield of M. alba silviculture in Southwest China.