Investigation Of Climbing Rose Varieties In Tianjin Andpreliminary Study On Adaptability Of Common Cultivars

In today's high-speed development of urbanization,the city's green land is of increasingly decreased.This requires us to screen plant varieties with both beautiful landscape effects and suitable indigenous characters to improve city's virescence.We first investigated the distribution and growth status of varieties of cultivated climbing rose in representative gardens in Tianjin.Our results showed that climbing rose was not widely accepted by administers of landscape and civilian,leading to a limited application in the city.Its application form is quite simplified.Thus,we suggest that introducing more climbing rose varieties from other places to Tianjin is urgent,making its landscape application widely.Moreover,we investigated preliminarily the growth status,photosynthesis,and other physiological/biochemical characters with four commonly used varieties of climbing rose grown in pots,including ‘Parade',‘Parkdirektor Riggers',‘Golden Celebration' and ‘Rattan Rainbow'.With these data,we further evaluated the suitability of these climbing rose in Tianjin with capabilities of salt and drought resistance.Under salt stress,the content of soluble sugar/protein,proline,and the enzymatic activity of superoxide dismutase,peroxidase in four climbing rose increased,while leaf area,leaf thickness,pigment,photosynthesis and root activity decreased.Among them,‘Parade' showed small changes,‘Rattan Rainbow' the biggest.For catalase(CAT),the ‘Parade' showed downward first and then upward,while ‘Parkdirektor Riggers',‘Golden Celebration',‘Rattan Rainbow showed the opposite trend.Under different concentration levels of salt stress,there are different changes among different treatments and different varieties.These may be due to the different mechanisms in different varieties.According to the result of subordinate function analysis and combined with the morphological construction of four climbing rose,we concluded that,from strong to weak,the intensity of salt resistance is ‘Parade',‘Parkdirektor Riggers',‘Golden Celebration',‘Rattan Rainbow',respectively.Under drought stress,the content of proline,soluble sugar and the enzymatic activity of peroxidase increased,while the leaf area,leaf thickness,pigment,photosynthesis,root activity,content of malondialdehyde,soluble protein decreased.The content of carotenoid,the enzymatic activity of superoxide dismutase and catalase showed contradictory,probably due to the different mechanisms in response to drought stress.Mechanisms of drought resistancein the climbing rose need further study.According to the result of subordinate function analysis and combined with the morphological construction of four climbing rose,we concluded that,from strong to weak,the intensity of drought resistance is ‘Parkdirektor Riggers' ‘Parade',‘Rattan Rainbow',‘Golden Celebration',respectively.In summary,from our investigation and test,the stress resistance of the four climbing rose,from strong to weak,is ‘Parkdirektor Riggers',‘Parade',‘Rattan Rainbow',‘Golden Celebration',respectively.The first two varieties,‘Parkdirektor Riggers',‘Parade',are recommended to use in landscape application in Tianjin.