野生玫瑰与玫瑰栽培品种光合特性的比较

Comparison of Photosynthetic Characteristics between Wild Plants and Cultivars of Rosa rugosa

以2个产地的野生玫瑰(吉林珲春野生玫瑰和山东牟平野生玫瑰)和2个玫瑰栽培品种(山东平阴的紫枝玫瑰和甘肃苦水的苦水玫瑰)为试材,利用CIRAS-2型便携式光合测定系统和FMS-2型调制式荧光仪对其叶片气体交换参数和叶绿素荧光参数日进程进行比较研究。结果表明:1)珲春野生玫瑰Pn日变化为单峰曲线,牟平野生玫瑰和紫枝玫瑰Pn日变化为不显著的双峰曲线,苦水玫瑰Pn日变化则为典型的双峰曲线;2个野生玫瑰的Pn最高值明显高于2个玫瑰栽培品种,表现出显著的高光合效率特性;珲春野生玫瑰、紫枝玫瑰和苦水玫瑰都表现出明显的光合“午休”,而牟平野生玫瑰没有“午休”;紫枝玫瑰Pn的降低主要是非气孔因素所致,而珲春野生玫瑰、牟平野生玫瑰和苦水玫瑰Pn的降低则受气孔和非气孔因素的共同影响。2)叶绿素荧光参数的日变化表明,4个玫瑰均出现了不同程度的光抑制,野生玫瑰比玫瑰栽培品种对高光强敏感,中午光抑制程度较大,但却比玫瑰栽培品种能更有效地利用上午的光能进行光合碳同化,而玫瑰栽培品种对下午光能的利用率比野生玫瑰高;PSⅡ反应中心的可逆失活和有效的非辐射能量耗散是玫瑰叶片防御光破坏的主要保护机制。

Photosynthetic characteristics of two wild roses （ Rosa rugosa, from Hunchun, Jilin Province and Muping, Shandong Province） and two rose cultivars （R. rugosa ‘Purple Branch‘ from Pingyin, Shandong Province and R. sertata × R. rugosa from Kushui, Gansu Province） were studied comparatively with CIRAS-2 portable photosynthetic instrument and FMS-2 fluorometer. The results showed that the curve of the diurnal change in the net photosynthetic rate （ P, ） of ‘ Hunchun’ wild rose showed only one peak, but that of ‘ Muping＇ wild rose and R. rugosa ‘Purple Branch＇ were all inapparent bimodal curves, and for R. sertata x R. rugosa, it was a typical bimodal curve. The maximal P, values of the wild roses were significantly higher than those of the two cultivars, especially from 6：30 to 14：30, and the wild roses showed the characteristic of high photosynthetic efficiency. ‘ Midday depression＇ phenomenon of photosynthesis occurred in ‘ Hunchun＇ wild rose, R. rugosa ‘ Purple Branch＇ and R. sertata × R. rugosa, nor ‘ Muping＇ wild rose. The depression of P, in R. rugosa ‘ Purple Branch＇ was mainly induced by non-stomatal factors, but for ‘Hunchun＇ wild rose, ‘Muping＇ wild rose and R. sertata × R. rugosa, it was jointly affected by stomatal factors and non-stomatal factors. The diurnal changes of the chlorophyll fluorescent parameters showed that photoinhibition occurred in all roses, but the wild roses were more sensible to strong light and showed a more serious photoinhibition than the rose cultivars at noon; they could use the light to carrying out photosynthesis more efficiently than the rose cultivars in the morning, but the rose cultivars could use the light more efficiently than the wild roses in the afternoon. The reversible inactivations of PSⅡ reaction centers and the course of dissipating excess energy efficiently through non-photochemical quenching （NPQ） were the main mechanism of protecting PSⅡ reaction centers of rose leaves from damaging by strong light.