不同基质对香港四照花幼苗生长及光合特性的影响

Effects of Different Substrates on Growth and Photosynthetic Characteristics of Dendrobenthamia hongkongensis Seedling

以香港四照花为试验材料,研究比较了6种不同栽培基质对其幼苗生长特性和光合特性的影响。结果表明,M6(即黄土∶沙土∶泥炭土的比例为1∶1∶1)混合基质最适合香港四照花生长。M6基质处理的植株地径、株高、冠幅3项生长指标均显著高于其他基质(P <0.05),该混合基质促进了香港四照花对养分的吸收利用和植株的生长发育,捕获光的能力得到增强,净光合速率(Pn)、水分利用效率(WUE)和气体交换等相关参数亦均优于其他基质;而单一基质M5 (珍珠岩)处理的植株生长发育和光合特性的相关指标最差,不利于幼苗的生长发育;其他单一或混合基质对植株生长的影响介于二者之间。认为黄土∶沙土∶泥炭土的比例为1∶1∶1的混合基质可作为香港四照花栽培基质推广。

The effects of six different substrates on the growth and photosynthetic characteristics of D. hongkongensis were studied. The results showed that the M6 mixed substrate (loess : sandy soil : peat soil in 1 : 1:1 ) created better conditions for the growth of D. hongkongensis. The growth indexes of diam- eter, height and crown with the M6 mixed substrates were all significant (P < 0.05). I'n addition, the mixed substrate promoted the absorption and utilization of nutrients by D. hongkongensis and enhanced the ability to capture light. The parameters of net photosynthetic rate, water use efficiency and gas ex-change were better than other five substrates. The parameters of growth and photosynthetic characteristics with the single substrate M5 (perlite-based) were the worst and not conducive to the seeding growth.Effects of other single or mixed substrates on plant growth were in between. The M6 mixed substrate of lo- ess: sandy soil : peat soil in 1: 1:1 was considered as the popularized one to cultivate D. hongkongensis.