[Impacts of salt stress on the growth and physiological characteristics of Rosa rugosa].

Taking 1-year-old cuttings of a wild type and three cultivars of Rosa rugosa as test materials, this paper studied their biomass, photosynthesis, osmotic adjustment substance contents, root activity, and ion contents under the stress of different concentration NaCl. Salt stress inhibited the growth of the cuttings, and root was more sensitive than shoot. Under salt stress, wild rose had significantly higher contents of free proline and soluble sugar than the cultivars, and the contents of free proline and soluble sugar in cultivar 'Ziyan' were higher than those in cultivars 'Zhongke 2' and 'Purple Branch'. Compared with rose cultivars, the wild rose under salt stress had smaller changes in its photosynthetic characteristics and root activity. It was suggested that wild rose had a higher resistance to salt stress than the cultivars, and cultivar 'Ziyan' had a higher resistance than 'Purple Branch' and 'Zhongke 2'. All the test indices could be used as the indicators of R. rugosa salt-tolerance.

Comparative analysis of headspace volatiles of Chinese Rosa rugosa.

The floral headspace compounds of Chinese Rosa rugosa germplasms that were isolated by an automated headspace sampler with built-in trap, and followed by gas chromatography-mass spectrometry for identification and quantification. Up to 33 volatile compounds were identified from the 23 rose germplasms, including nine alcohols, five esters, three alkanes, 10 terpenes, three aldehydes, two ketones, and one ether. The main floral components identified were 2-phenylethanol, ß-citronellol, ethanol, and n-hexane. 'xizi', 'miaofengshan', 'xiangciguo', and 'tangbai' contained the highest amounts of 2-phenylethanol at 84.66 µg·g⁻¹, ß-citronellol at 70.98 µg·g⁻¹, ethanol at 83.87 µg·g⁻¹, and n-hexane at 18.23 µg·g⁻¹, respectively. 'Rongchengyesheng', 'tanghong', 'xizi', 'miaofengshan', and 'baizizhi' could be considered good materials for extracting rose oil and breeding new cultivars.