表皮蜡质对‘翠鸟’玉簪生理特性的影响

Effects of Epidermal Wax on Physiological Characteristics of Hosta ‘Halcyon’

为探究表皮蜡质对植物抗旱性的影响,以蓝叶玉簪‘翠鸟’(Hosta‘Halcyon’)为研究对象,采用盆栽方法,通过干旱胁迫(土壤相对含水量为50%)和人工除蜡,将试验分为4种处理,分别为正常给水有蜡质(ZY)、正常给水无蜡质(ZW)、干旱处理有蜡质(GY)以及干旱处理无蜡质(GW),分析了蜡质对‘翠鸟’玉簪生理特性的影响。结果表明:在两种水分条件下,表皮自然覆有蜡质的叶片净光合速率、蒸腾速率、气孔导度和叶绿素含量等均高于人工去除表皮蜡质的叶片;随着时间的延长,各处理净光合速率都显著降低(p<0.05),且每1处理在14d时都达到了最低,最低值0.97μmol·m^(-2)·s^(-1),为干旱无蜡质处理。在干旱胁迫处理中,表皮有蜡质处理的水分利用效率在各个时间段均高于表皮无蜡质处理。随着时间的延长,4种处理的叶温总体呈现出逐渐升高的趋势,干旱无蜡质处理的叶片温度最高,正常给水有蜡质处理温度最低。在每一个时间节点上的离体失水率都是无蜡质的叶片高于有蜡质覆盖的叶片;干旱处理组的失水率总体上较正常处理组的失水速度低,且离体失水率随着时间的延长有先增加后降低的趋势。Fv/Fm的最小值均出现在4种处理后的第14天,且‘翠鸟’正常给水处理的Fv/Fm显著高于干旱胁迫处理,Fv/Fm的大小呈现出:ZY>ZW>GY>GW。本研究进一步明确了阴生植物‘翠鸟’玉簪叶片表皮蜡质在抗旱中的保水作用。

In order to explore the effect of epidermal wax on the drought resistance of plants, blue leaf species Hosta ‘Halcyon’grown in pots, through drought stress（soil relative water content 50%） and artificial wax removal, were divided into four different treatments（normal water supply with wax, ZY; normal supply without wax, ZW; drought treatment with wax, GY; drought treatment without wax, GW）. The study analyzed the influence of epidermis wax covered on the surface of shade plant Hosta‘Halcyon’ to the physiological characteristics under drought stress. The results showed that under the two water conditions, the net photosynthetic rate, transpiration rate, stomatal conductance and chlorophyll contents of the leaves covered with wax were higher than those of the leaves with artificial epidermis wax removal. With the time the net photosynthetic rate of each treatment was significantly decreased（p 〈0.05）, each treatment reached the lowest at 14 d and the lowest value was 0.97μmol·m-2·s-1 of GW. Under drought stress, the water use efficiency of the treatment GY was higher than that of the treatment GW in each period. The leaf temperature showed a gradual increase with the prolongation of time in four treatments, The leaf temperature of the treatment GW was the highest, and the treatment ZY was the lowest. The water loss rate of the leaves without wax was higher than the leaves with wax. The water loss rate of the drought treatment group was lower than that of the normal treatment group, it increased first and then decreased with the time. In the four treatments, the minimum value of Fv/Fm appeared on the 14 th day after treatment, and the Fv/Fm of normal water treatment was significantly higher than that of drought stress, and the size of 4 treatment Fv/Fm showed： ZY〉 ZW〉 GY 〉 GW. This study further defined the effects of epidermis wax covered on the surface of shade plant Hosta ‘Halcyon’ on drought stress and water retention.