紫枝玫瑰与重瓣红玫瑰在半干旱沙区花期生理适应性及抗旱性OA

To screen Rosa rugosa germplasm resources suitable for cultivation in semi-arid sandy areas and clarify the adaptive differences and drought-tolerant physiological mechanisms of different R.rugosa cultivars in such regions,field adaptation trials were conducted in Tailai County,Qiqihar City-a typical semi-arid sandy zone-using R.rugosa'Zizhi'introduced from Pingyin County,Jinan City,Shandong Province,and R.rugosa'Plena'introduced from Qingcheng Village,Ning'an City,Heilongjiang Province as research materials.Intact petals of the two R.rugosa cultivars were collected across five flowering stages:bud stage,initial blooming stage,half-blooming stage,full blooming stage,and late full blooming stage.Petal morphological traits were systematically observed,and petal area was measured.Meanwhile,drought tolerance-relat-ed physiological indices were determined,including mass fractions of petal pigments(anthocyanins and carotenoids),ac-cumulation levels of basic physiological substances(water content,soluble sugars,and soluble proteins),activities of an-tioxidant enzymes(SOD and POD),molality of membrane lipid peroxidation product(malondialdehyde,MDA),and mass fraction of osmotic adjustment substance(proline).The membership function method was adopted to comprehensively evaluate drought resistance of the two cultivars.The results showed that both R.rugosa cultivars could complete the entire flowering developmental cycle in the semi-arid sandy area of Tailai County,while significant inter-cultivar differences exis-ted in morphological formation(e.g.,petal area)and physiological metabolic responses.The petal pigment content of R.rugosa'Plena'was significantly higher than that of R.rugosa'Zizhi',presenting superior flower color quality.In con-trast,R.rugosa'Zizhi'maintained relatively high tissue water content and soluble sugar accumulation at the late full blooming stage.Its peak SOD and POD activities were 34.8%and 79.3%higher than those of R.rugosa'Plena',re-spectively,and the molality of MDA remained consistently low(≤0.53μmol·g-1).By comparison,drought tolerance-related physiological indices of R.rugosa'Plena'fluctuated drastically,with its MDA molality at the late full blooming stage 52.8%higher than that of R.rugosa'Zizhi',indicating severer membrane lipid peroxidation damage.Based on the comprehensive evaluation values calculated by the subordinate function method,the average subordinate function value of R.rugosa'Zizhi'was 0.643,while that of R.rugosa'Plena'was 0.315.Overall,R.rugosa'Zizhi'exhibited stron-ger drought resistance than R.rugosa'Plena'.