不同栽培基质对碧玉兰光响应特性的影响

 为筛选出适合碧玉兰盆花无土栽培用的基质配方，采用LI-6400光合作用测定系统，以云南泥炭、椰丝，桤木树皮、梨树皮混合而成的9种栽培基质的碧玉兰叶片的光响应曲线进行了测定并采用了YE［1］构建的光响应新模型进行拟合。结果表明：9种栽培基质下碧玉兰的光合特性存在一定的差异，M3(椰丝)、M7［桤木树皮∶泥炭∶椰丝∶梨树皮=1∶1∶2∶1(体积比）］栽培基质下的碧玉兰光饱和点(LSP)分别为42380, 56344μmol/(m2·s)，最大净光合速率(Pmax)分别为528，451μmol/( m2·s)，均相对较高，表观量子效率(AQY)分别为00759，00743μmol/mol,说明M3, M7栽培基质下碧玉兰对弱光的利用率较高，气孔限制值(Ls较小，其水分利用率(WUE)也较高。试验结果表明，M3, M7是适合碧玉兰的栽培基质。

Studies on Photosynthetic Response of Cymbidium lowianum of Various Media

The photosynthetic characteristics of Cymbidium lowianum selected for medium formula were measured with the Li 6400 portable photosynthesis system and the new light response model by YE［1］ was applied to fit the measured data reasonably on the photosynthetic light-response curve of various medium formula．The results showed that various medium formula had different photosynthetic characteristics．The maximum photosynthetic net rate (Pmax)，light saturation point (LSP)，apparent quantum yield (AQY)，apparent carboxylation efficiency (ACE) in M3（shredded coconut），M7 ［alnus bark: peat: shredded coconut: pear bark=1∶1∶2∶1(volume ratio)］ were higher those of than treatments that the other. Furthermore, The water use efficiency (WUE) of M3, M7 was higher than the other because of stomatal limiting value in other medium formula than in M3, M7. The results indicated that M3, M7 showed higher ability of utilizing low light and WUE, so M3, M7 formula was the best medium for soilless culture of pot C. lowianum plants．