Chin J Plant Ecol ›› 2022, Vol. 46 ›› Issue (12): 1562-1572.DOI: 10.17521/cjpe.2022.0172

• Research Articles • Previous Articles     Next Articles

Calcium-tolerance type and adaptability to high-calcium habitats of Rosa roxburghii

MENG Qing-Jing, FAN Wei-Guo()   

  1. College of Agriculture, Guizhou University, Engineering Technology Research Centre for Rosa roxburghii of National Forestry and Grassland Administration, Guiyang 550025, China
  • Received:2022-04-29 Accepted:2022-08-22 Online:2022-12-20 Published:2023-01-13
  • Contact: *FAN Wei-Guo(wgfan@gzu.edu.cn)

Abstract:

Aims Rosa roxburghii is a special economic tree species native to southwest China, and it has been taken as a key fruit tree in karst mountainous areas of Guizhou Province. However, it is unclear whether R. roxburghii can adapt to high-calcium habitats in the karst areas. To provide scientific evidence for determining the potential planting sites of R. roxburghii, the calcium-tolerance type and adaptability to high-calcium habitats of R. roxburghii were needed to be clarified.

Methods In this study, different organs from 50 R. roxburghii individuals and different calcareous soils where R. roxburghii grew were sampled in karst areas of Guizhou. The pH, exchangeable calcium and magnesium contents in the soil, total calcium and calcium oxalate contents in the plant organs, and calcium and magnesium contents in the leaves were determined, and the proportion of calcium oxalate in different organs to total calcium content was calculated. Then, the correlations between the exchangeable calcium and magnesium content in the soil with total calcium in different organs, and calcium and magnesium content in the leaves were analyzed. In addition, the distribution of calcium oxalate crystals in different organs as well as on the leaf surface was observed in samples collected from low-calcium and high-calcium habitats.

Important findings The soil at R. roxburghii sites in karst areas had a high pH, and the content of exchangeable calcium and magnesium was abundant and varies greatly. In different calcareous habitats, the total calcium content in different organs of R. roxburghii was significantly and positively correlated with the exchangeable calcium content in the soil. Similarly, the contents of total calcium and magnesium in the leaves were correlated with those in the soil. The branches and leaves were the organs that accumulated the most calcium, whereas the calcium enrichment in the roots and fruit were relatively low. The total calcium and magnesium contents of all the sample leaves ranged from 1.71% to 2.73%, among which, the proportions of calcium oxalate in branches and leaves were 55.81% and 52.76% of the total calcium, respectively; while only 29.34% and 34.30% were in roots and fruit. In samples from a high-calcium habitats, calcium oxalate prismatic crystals were abundant in the branches, leaves, and around stomatal pores, while few needle crystals were observed in the fruits. However, in samples from a low-calcium environment, no calcium oxalate crystals were observed in the roots, fruit, and leaf stomatal pores. In this study, we clarified that the R. roxburghii is an intermediate type of calcium-tolerance, which has strong adaptability to different calcium habitats in karst areas. The physiological characteristics of storing abundant calcium oxalate crystals in branches and leaves, and excreting calcium through leaf stomata play important roles in reducing the calcium concentration in R. roxburghii tissues and alleviating damages from high-calcium stress. The results of this study provide important guidance for the determination of suitable planting sites for R. roxburghii in karst areas.

Key words: Rosa roxburghii, karst area, high-calcium habitat, calcium-tolerance type, adaptability analysis