RESUMO
Objective: To investigate the colonization of arbuscular mycorrhizal fungi (AMF) and dark septate endophytes (DSE) in the roots of Polygonatum kingianum planted at different areas, and explore the correlations between the colonization rate and the main functional components. Methods: Fresh roots of P. kingianum from five plots in Yunnan Province were taken as research objects. The alkali dissociation method was used to investigate the colonization of AMF and DSE in the roots of P. kingianum. Then the morphological structure was photographed. The content of P. sibiricum polysaccharides, diosgenin, total flavonoids and extractum were separately determined by phonel-sulfate method, colorimetry method of vanillin-acetic acid-perchloric acid, spectrophotometry method with rutin standard and hot dipping method with alcohol. The correlations between the colonization rates of AMF or DSE and four main functional components were analyzed by Pearson correlation coefficient method. Results: The average colonization of AMF and DSE in the five plots were 26.25%-57.54% and 31.67%-45.19%, respectively. The colonization rates of AMF and DSE from HHMZ was higher than the other four others. All of correlations among the colonization rates of AMF, DSE and their typical structure and the four main functional components in the rhizomes were positive correlation, in which the correlations between the content of polysaccharides, diosgenin or total flavonoids and the colonization rates of AMF or DSE were higher, and their correlation coefficient were respectively 0.838/0.887, 0.819/0.703, and 0.785/0.855 (AMF/DSE). Furthermore, the correlations between the content of polysaccharides and the colonization rates of AMF hypha or DSE were significant. In addition, there were high correlations among the colonization rates of AMF, DSE and their typical structures, as well as the content in pairs of four functional components. Conclusion: There were higher colonization rates of AMF and DSE in the fibrous roots of P. kingianum. The correlations between the colonization rates of AMF or DSE and each main functional component were positive. This study provides data support and experimental basis for the implementation of ecological planting of P. kingianum and the use of biological means to increase production and income.rates
RESUMO
Asteraceae family shows a great diversity in Cuba and presents threatened taxons in high number. Pinar del Río has 19 threatened species belonging to this family and three of them are characteristic of a sandy (quartzitic) soil at the Reserva Florística Manejada San Ubaldo-Sabanalamar (Floristic Reserve San Ubaldo-Sabanalamar). The arbuscular mycorrhizal status and colonization rate in Aster grisebachii, Erigeron bellidiastroides, Erigeron cuneifolius, Pectis juniperina and Sachsia polycephala (Asteraceae) from this Reserve was determined in October 2009 and April 2010, during hydrologic rainy and dry period, respectively. All species were mycotrophic in both periods with a high percentage of colonization rates, between 66 and 100% in rainy period and between 84 and 100% in dry period. Vesicles, arbuscules, spores, hyphal and arbuscular coils of arbuscular mycorrhizae were observed. Paris -type and Arum -type morphologies (both) were observed indistinctly in all the species, and Intermediate type was observed only in Aster grisebachii and Erigeron bellidiastroides, which could be a hint that these species are colonized by more than one fungal species, and therefore enhancing the relevance of fungal identity as a considerable character in the morphology association. Also, septate hyphae and microsclerotium of dark septate endophytes were identifyed inside the roots of all the species.
La familia Asteraceae muestra una gran diversidad en Cuba y presenta un elevado número de taxones amenazados. Pinar del Río cuenta con 19 especies amenazadas pertenecientes a esta familia, de las cuales tres son características de los suelos arenosos cuarcíticos de la Reserva Florística Manejada San Ubaldo-Sabanalamar. Se determinó el estatus micorrízico arbuscular y la tasa de colonización de Aster grisebachii, Erigeron bellidiastroides, Erigeron cuneifolius, Pectis juniperina y Sachsia polycephala (Asteraceae) presentes en esta Reserva, en octubre del 2009 y abril del 2010, durante los períodos hidrológicos húmedo y seco, respectivamente. Todas las especies estaban micorrizadas en ambos períodos con elevados porcentaje de colonización micorrízica, entre 66 y 100% en el período lluvioso y entre 84 y 100% en el período seco. Se identificaron vesículas, arbúsculos, esporas, enrollados hifales y arbusculares característicos de las micorrizas arbusculares. Los tipos morfológicos Paris y Arum (ambos) fueron observados indistintamente en todas las especies, y el tipo Intermedio solo se observó en Aster grisebachii y Erigeron bellidiastroides, lo cual sugiere la colonización de estas especies por más de una especie fúngica y con ello la importancia de la identidad fúngica en la determinación de la morfología de la asociación. Se identificaron además, hifas septadas y microesclerosios de endófitos oscuros septados en el interior de las raíces de todas las especies estudiadas.